MSP432 User's Guide Driver Lib Users MSP432P4xx 3 21 00 05
MSP432_DriverLib_Users_Guide-MSP432P4xx-3_21_00_05
User Manual: Pdf
Open the PDF directly: View PDF 
.
Page Count: 389
| Download | |
| Open PDF In Browser | View PDF |
MSP432® Peripheral Driver Library
USER’S GUIDE
Copyright © 2016 Texas Instruments Incorporated.
Copyright
Copyright © 2016 Texas Instruments Incorporated. All rights reserved. MSP430/MSP432 and MSPWare are trademarks of Texas Instruments Instruments. ARM and Thumb are registered trademarks and Cortex is a trademark of ARM Limited. Other names and brands may be claimed as the property
of others.
Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of Texas Instruments semiconductor products and disclaimers thereto appears at the end of this document.
Texas Instruments
13532 N. Central Expressway MS3810
Dallas, TX 75243
www.ti.com/
Revision Information
This is version of this document, last updated on Thu Jan 21 2016 12:34:41 AM.
Thu Jan 21 2016 12:34:41 AM
1
Table of Contents
Table of Contents
Copyright . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1
Revision Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1
1
1.1
1.2
1.3
1.4
1.5
1.6
DriverLib Introduction . . . .
What DriverLib is . . . . . . . .
What DriverLib is not . . . . .
Cross Module Considerations
DriverLib in ROM . . . . . . .
MSP430 Legacy APIs . . . . .
Quick Start . . . . . . . . . . .
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
3
3
4
4
5
5
7
2
2.1
2.2
2.3
2.4
2.5
2.6
14-Bit Analog-to-Digital Converter (ADC14)
Module Operation . . . . . . . . . . . . . . . .
Conversion Modes . . . . . . . . . . . . . . . .
Repeat Modes . . . . . . . . . . . . . . . . . .
Conversion of Results . . . . . . . . . . . . . .
Programming Example . . . . . . . . . . . . .
Definitions . . . . . . . . . . . . . . . . . . . .
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
8
8
8
9
10
10
12
3
3.1
3.2
3.3
3.4
3.5
Advanced Encryption Standard 256 Module (AES256)
Module Operation . . . . . . . . . . . . . . . . . . . . . .
Key Features . . . . . . . . . . . . . . . . . . . . . . . . .
Encryption/Decryption Cycle Times . . . . . . . . . . . .
Programming Example . . . . . . . . . . . . . . . . . . .
Definitions . . . . . . . . . . . . . . . . . . . . . . . . . .
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
29
29
29
30
30
31
4
4.1
4.2
4.3
Analog Comparator (COMP_E)
Module Operation . . . . . . . .
Programming Example . . . . .
Definitions . . . . . . . . . . . .
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
40
40
41
42
5
5.1
5.2
5.3
Cyclic Redundancy Check 32 (CRC32)
Module Operation . . . . . . . . . . . . .
Programming Example . . . . . . . . . .
Definitions . . . . . . . . . . . . . . . . .
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
60
60
60
61
6
6.1
6.2
6.3
6.4
6.5
6.6
Clock System (CS) . . . . . . . . . . . .
Module Operation . . . . . . . . . . . . .
Timeout Parameters . . . . . . . . . . . .
Custom DCO Frequency . . . . . . . . .
Specifying External Crystal Frequencies
Programming Example . . . . . . . . . .
Definitions . . . . . . . . . . . . . . . . .
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
65
65
65
65
65
66
67
7
7.1
7.2
7.3
Direct Memory Access Controller (DMA)
Module Operation . . . . . . . . . . . . . .
Programming Example . . . . . . . . . . .
Definitions . . . . . . . . . . . . . . . . . .
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
83
83
85
86
8
8.1
8.2
8.3
8.4
Flash Memory Controller (FlashCtl)
Module Operation . . . . . . . . . . .
Flash Controller Limitations . . . . . .
Wait State Considerations . . . . . .
Programming Example . . . . . . . .
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
101
101
101
101
102
Thu Jan 21 2016 12:34:41 AM
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
2
Table of Contents
8.5
Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103
9
9.1
9.2
9.3
Floating Point Unit (FPU)
Module Operation . . . . .
Programming Example . .
Definitions . . . . . . . . .
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
122
122
123
124
10
10.1
10.2
10.3
10.4
General Purpose Input/Output (GPIO) .
Module Operation . . . . . . . . . . . . .
Key Features . . . . . . . . . . . . . . . .
Programming Example . . . . . . . . . .
Definitions . . . . . . . . . . . . . . . . .
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
129
129
129
130
131
11
11.1
11.2
11.3
11.4
11.5
11.6
Inter-Integrated Circuit (I2C)
I2C Module Operation . . . . .
Master Operation . . . . . . .
Slave Operation . . . . . . . .
Timeout Parameters . . . . . .
Programming Example . . . .
Definitions . . . . . . . . . . .
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
162
162
162
163
164
164
165
12
12.1
12.2
12.3
12.4
Nested Vector Interrupt Controller (NVIC)
Module Operation . . . . . . . . . . . . . . .
Basic Operation Modes . . . . . . . . . . . .
Programming Example . . . . . . . . . . . .
Definitions . . . . . . . . . . . . . . . . . . .
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
196
196
197
197
198
13
13.1
13.2
13.3
13.4
Memory Protection Unit (MPU)
Module Operation . . . . . . . .
Module Operation . . . . . . . .
Programming Example . . . . .
Definitions . . . . . . . . . . . .
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
208
208
208
209
210
14
14.1
14.2
14.3
14.4
14.5
14.6
14.7
Power Control Module (PCM) . . . .
Module Operation . . . . . . . . . . .
Switching States . . . . . . . . . . . .
Switching Modes/Levels . . . . . . . .
Low Power Mode and State Retention
Enabling/Disabling Rude Mode . . . .
Programming Example . . . . . . . .
Definitions . . . . . . . . . . . . . . .
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
217
217
217
217
218
218
219
220
15
15.1
15.2
15.3
Port Mapper (PMAP) .
Module Operation . . .
Programming Example
Definitions . . . . . . .
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
235
235
235
236
16
16.1
16.2
16.3
Power Supply System (PSS)
Module Operation . . . . . . .
Programming Example . . . .
Definitions . . . . . . . . . . .
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
238
238
238
239
17
17.1
17.2
17.3
Reference Module (REF_A)
Module Operation . . . . . .
Programming Example . . .
Definitions . . . . . . . . . .
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
245
245
245
246
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
18 Reset Controller (ResetCtl) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 251
18.1 Module Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 251
Thu Jan 21 2016 12:34:41 AM
3
Table of Contents
18.2 Reset Sources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 251
18.3 Programming Example . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 251
18.4 Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 253
19
19.1
19.2
19.3
Real Time Clock (RTC_C)
Module Operation . . . . .
Programming Example . .
Definitions . . . . . . . . .
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
261
261
262
263
20
20.1
20.2
20.3
20.4
Serial Peripheral Interface (SPI)
Module Operation . . . . . . . . .
Basic Operation Modes . . . . . .
Programming Example . . . . . .
Definitions . . . . . . . . . . . . .
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
275
275
275
276
277
21
21.1
21.2
21.3
System Control Module (SysCtl)
Module Operation . . . . . . . . .
Programming Example . . . . . .
Definitions . . . . . . . . . . . . .
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
307
307
307
308
22
22.1
22.2
22.3
System Tick (SysTick)
Module Operation . . .
Programming Example
Definitions . . . . . . .
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
319
319
319
320
23
23.1
23.2
23.3
23.4
32-bit ARM Timer (Timer32)
Module Operation . . . . . .
Basic Operation Modes . . .
Programming Example . . .
Definitions . . . . . . . . . .
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
324
324
324
325
326
24
24.1
24.2
24.3
24.4
16-Bit Timer with Precision PWM (Timer_A)
Module Operation . . . . . . . . . . . . . . . .
Basic Operation Modes . . . . . . . . . . . . .
Programming Example . . . . . . . . . . . . .
Definitions . . . . . . . . . . . . . . . . . . . .
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
334
334
334
335
336
25
25.1
25.2
25.3
Universal Asynchronous Receiver/Transmitter (UART)
Module Operation . . . . . . . . . . . . . . . . . . . . . . .
Programming Example . . . . . . . . . . . . . . . . . . . .
Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . .
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
364
364
365
366
26
26.1
26.2
26.3
26.4
26.5
26.6
Watchdog Timer (WDT_A)
Module Operation . . . . . .
Watchdog Mode . . . . . . .
Interval Mode . . . . . . . .
Setting Reset Type . . . . . .
Programming Example . . .
Definitions . . . . . . . . . .
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
381
381
381
381
382
382
383
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
IMPORTANT NOTICE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 388
Thu Jan 21 2016 12:34:41 AM
4
DriverLib Introduction
1
DriverLib Introduction
What DriverLib is . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
What DriverLib is not . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Cross Module Considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
DriverLib in ROM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
MSP430 Legacy APIs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Quick Start . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
1.1
What DriverLib is
The Texas Instruments MSP432 Driver Library (DriverLib) is a set of fully functional APIs used to
configure, control, and manipulate the hardware peripherals of the MSP432 platform. In addition
to being able to control the MSP432 peripherals, DriverLib also gives the user the ability to use
common ARM peripherals such as the Interrupt (NVIC) and Memory Protection Unit (MPU) as well
as MSP430 peripherals such as the eUSCI Serial peripherals and Watchdog Timer (WDT).
DriverLib for MSP432 Series has been tested and compiled under a variety of different toolchains.
Subsequently, for each toolchain a specific debugger was used for testing validation. Below is a
list that contains the supported toolchain and corresponding hardware debugger used.
Texas Instruments Code Composer Studio 6.1 (XDS100v3)
IAR Embedded Workbench for ARM 7.30 (SEGGER J-LINK)
GNU C Compiler 4.8 (gcc) (SEGGER J-LINK)
Keil Embedded Development Tools for ARM 5.13 (KEIL U-LINK Pro)
The DriverLib is meant to provide a "software" layer to the programmer in order to facilitate higher
level of programming compared to direct register accesses. Nearly every aspect of a MSP432
device can be configured and driven using the DriverLib APIs. By using the high level software
APIs provided by DriverLib, users can create powerful and intuitive code which is highly portable
between not only devices within the MSP432 platform, but between different families in the
MSP430/MSP432 platforms.
Writing code in DriverLib will make user code more legible and easier to share among a group. For
example, examine the following pair of code snippets. Both sets of code set MCLK to be sourced
from VLO with a divider of four:
Traditional Register Access
CSKEY = 0x695A;
CSCTL1 |= SELM_1 | DIVM_2;
CSKEY = 0;
DriverLib Equivalent
CS_initClockSignal(CS_MCLK,
CS_VLOCLK_SELECT,
CS_CLOCK_DIVIDER_32);
As can be seen, the DriverLib API is readable, sensible, and easy to program for the software
engineer. Additionally, DriverLib APIs for other platforms such as MSP430 will use very similar (if
not identical) APIs giving code written with DriverLib APIs a boost in portability.
Thu Jan 21 2016 12:34:41 AM
5
DriverLib Introduction
1.2
What DriverLib is not
The Driver Library is not meant to provide a layer of intelligence on the level of a user application.
It is meant to be an aid to the programmer to be part of the larger solution- not the solution itself.
Interrupt handlers are also not included with the DriverLib APIs. APIs to manage/enable/disable
interrupts are included, however the actual authoring of the interrupt service routine is left up to
the programmer. For reference, A typical interrupt handler that takes advantage of DriverLib APIs
can be seen in the following code snippet:
void port6_isr(void)
{
uint32_t status = GPIO_getEnabledInterruptStatus(GPIO_PORT_P6);
GPIO_clearInterruptFlag(GPIO_PORT_P6,
status);
if (status & GPIO_PIN7)
{
if (powerStates[curPowerState] == PCM_LPM3)
{
curPowerState = 0;
}
stateChange = true;
}
}
1.3
Cross Module Considerations
Each DriverLib module will, for the most part, only interact and configure the module that it is
designed for. Any cross-module interaction is left up to the user. For example, when changing
power modes to a low frequency mode with the PCM module, the user will have to ensure that the
proper frequency requirements are configured with the CS module (low frequency requires that
the system frequency be no greater that 128Khz).
Calling the following API alone while MCLK is greater that 128Khz will result in a system error:
PCM_setPowerState(PCM_AM_LF_VCORE1);
This is because the DriverLib module will not account for the overall system frequency of the
system. Instead, similar APIs to the following must be called in conjunction:
CS_setReferenceOscillatorFrequency(CS_REFO_128KHZ);
CS_initClockSignal(CS_MCLK, CS_REFOCLK_SELECT, CS_CLOCK_DIVIDER_1);
PCM_setPowerState(PCM_AM_LF_VCORE1);
Cross-module considerations such as these must be taken when programming with DriverLib APIs
as DriverLib was not designed to account for high level system requirements.
Thu Jan 21 2016 12:34:41 AM
6
DriverLib Introduction
1.4
DriverLib in ROM
With all MSP432 devices, a copy of DriverLib is included within the device’s ROM space. This
allows programmers to take advantage of using high level APIs without having to worry about
additional memory overhead of a flash library. In addition to a more optimized execution, the user
can drastically cut down the memory footprint requirement of their application when using the
software Driver Libraries available in ROM.
Accessing Driver Library APIs in ROM is as easy as including the rom.h header file, and then
replacing normal API calls with a ROM_ prefix. For example, take the following API from the pcm.c
module that changes the power state to PCM_AM_DCDC_VCORE1:
PCM_setPowerState(PCM_AM_DCDC_VCORE1);
After including the rom.h file, all that would have to be done to switch to the ROM equivalent of the
API would be add the ROM_ prefix to the API:
ROM_PCM_setPowerState(PCM_AM_DCDC_VCORE1);
While the majority of DriverLib APIs are available in ROM, due to architectural limitations some
APIs are omitted from being included in ROM. In addition, if any bug fixes were added to the API
after the device ROM was programmed, it is desirable to use the flash version of the API. An
"intelligence" has been created to account for this problem. If the user includes the rom_map.h
header file and uses the MAP_ prefix in front of the API, the header file will automatically use
preprocessor macros to decide whether to use a ROM or flash version of the API.
MAP_PCM_setPowerState(PCM_AM_DCDC_VCORE1);
1.5
MSP430 Legacy APIs
Since the MSP432 platform is built with many modules from Texas Instruments’ MSP430 platform,
many shared modules exist between MSP430 and MSP432. For this reason, a "compatibility"
layer is provided to provide between the MSP430 Driver Library and the MSP430 Driver Library.
The following modules are shared between MSP432 and MSP430:
AES256
COMP_E
CRC32
GPIO
EUSCI_A_SPI (SPI)
EUSCI_A_UART (UART)
EUSCI_B_I2C (I2C)
EUSCI_B_SPI (SPI)
PMAP
REF_A
RTC_C
Thu Jan 21 2016 12:34:41 AM
7
DriverLib Introduction
TIMER_A
WDT_A
To use these legacy APIs, no additional work is needed. All that is needed is to include the header
file of the module you want to use and both the old and the new APIs will be available. For
example, for WDT_A:
#include
By including this header file, the user is granted access to all of the legacy DriverLib APIs from
MSP430 Driver Library verbatim. For additional documentation on the MSP430 implementation of
DriverLib, please refer to the MSP430Ware Website.
Many of the APIs were simplified and refactored for the MSP432 version of Driver Library. For
example, to halt the watchdog module for a 5xx MSP430 device, the following API is used:
WDT_A_hold(WDT_A_BASE);
Thu Jan 21 2016 12:34:41 AM
8
DriverLib Introduction
For MSP432 Driver Library, this same API has been simplified to the following API:
WDT_A_holdTimer();
Note that while many Driver Library APIs are shared between MSP430 and MSP432, there are a
few underlying differences between the two architectures. Interrupts, for example, are a bit
difference on MSP432 compared to MSP430 due to integration with ARM’s interrupt controller (the
NVIC). While each module will still have individual status (IFG), enable/disable, and clear bits,
interrupt service routines now have to be associated with the ARM NVIC before usage.
1.6
Quick Start
Getting started using DriverLib for MSP432 Series is very simple regardless of the chosen
development environment.
An empty "skeleton" project is provided in the examples directory of the MSPWare release. This
project includes links to the DriverLib library as well as everything that is needed for the
programmer to immediately start writing a DriverLib application. A user can import this project in
CCS using the TI Resource Explorer, or open the workspace with IAR Embedded Workbench for
ARM or KEIL uVision 5. All of the include paths and compiler options are set up to allow the user
to seamlessly start development on their MSP432 DriverLib application.
The GNU compiler tools for ARM are fully supported by the MSP432 Series DriverLib. While no
IDE in specific is supported, Makefiles are provided for both the library and all of the code
examples. Vector table definitions that are compatible with the GCC compiler are also provided for
code examples in the startup_gcc.c file for each individual code example. For the GNU tools,
separate header files are included in the inc directory of the root installation of DriverLib. These
header files are the latest that are available at the time of DriverLib release, however newer
header files may be downloaded as a part of the CCS installation.
Thu Jan 21 2016 12:34:41 AM
9
14-Bit Analog-to-Digital Converter (ADC14)
2
14-Bit Analog-to-Digital Converter (ADC14)
Module Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Conversion Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Repeat Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Conversion of Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Programming Example . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
2.1
Module Operation
The ADC14 module for Driver Library is designed to allow the user to make simple analog to
digital conversions as well make complex and simultaneous conversions across multiple channels.
2.2
Conversion Modes
With Single Conversion Mode, the user will sample only a single ADC channel which will be stored
in a single ADC memory location. This is the most basic ADC sample/convert mode and allows for
very simple measurements on a single channel. To configure single sample mode, only a single
destination is configured for the sample/conversion result. The following is a code snippet for
configuring/initializing the ADC module in single conversion mode as well as kicking off the start of
conversion/sampling.
/* Initializing ADC (MCLK/1/4) */
MAP_ADC14_enableModule();
MAP_ADC14_initModule(ADC_CLOCKSOURCE_MCLK,
0);
ADC_PREDIVIDER_1,
/* Configuring GPIOs (5.5 A0) */
MAP_GPIO_setAsPeripheralModuleFunctionInputPin(GPIO_PORT_P5,
GPIO_TERTIARY_MODULE_FUNCTION);
/* Configuring ADC Memory */
MAP_ADC14_configureSingleSampleMode(ADC_MEM0,
MAP_ADC14_configureConversionMemory(ADC_MEM0,
ADC_INPUT_A0, false);
ADC_DIVIDER_4,
GPIO_PIN5,
true);
ADC_VREFPOS_AVCC_VREFNEG_VSS,
/* Configuring Sample Timer */
MAP_ADC14_enableSampleTimer(ADC_MANUAL_ITERATION);
/* Enabling/Toggling Conversion */
MAP_ADC14_enableConversion();
MAP_ADC14_toggleConversionTrigger();
Thu Jan 21 2016 12:34:41 AM
10
14-Bit Analog-to-Digital Converter (ADC14)
When using single sample mode, only one memory location will be written for a
conversion/sample cycle. To access the result of this conversion, the ADC14_getResult API is
used with the corresponding memory location specified. This is usually done within the interrupt
service routine of the ADC module.
/* ADC Interrupt Handler. This handler is called whenever there is a conversion
* that is finished for ADC_MEM0.
*/
void ADC14_IRQHandler(void)
{
uint64_t status = MAP_ADC14_getEnabledInterruptStatus();
MAP_ADC14_clearInterruptFlag(status);
if (ADC_INT0 & status)
{
curADCResult = MAP_ADC14_getResult(ADC_MEM0);
normalizedADCRes = (curADCResult * 3.3) / 16384;
MAP_ADC14_toggleConversionTrigger();
}
}
The ADC14 APIs also support the setup/configuration of multiple conversion mode. With multiple
conversion mode, multiple ADC channels are sampled and stored in multiple ADC memory
addresses in a single sweep. This is particularly useful when the user wants to take a sample of
multiple channels over a period of time (also known as scan mode). The
ADC14_getMultiSequenceResult function is used to populate the given array pointer with the
result over a wide memory arrange (setup with ADC14_configureMultiSequenceMode ).
2.3
Repeat Modes
When configuring the ADC module to use multiple or single sample/conversion mode, a boolean
argument is provided to signal whether the DriverLib ADC module should work in "repeat" mode.
With repeat mode, once a conversion/sample is completed and read by the API, a new conversion
happens until the user manually stops conversion using the ADC14_toggleConversionTrigger
command. Repeat mode is useful when the user wants to continuously sample an ADC channel
over an extended period of time.
When repeat mode is specified to be false, whenever a conversion/sample is finished and read
from the result register, the module will stop conversion until called by the
ADC14_toggleConversionTrigger function.
Thu Jan 21 2016 12:34:41 AM
11
14-Bit Analog-to-Digital Converter (ADC14)
2.4
Conversion of Results
When reading a result of an ADC14 conversion, it is important to note that the result will be
relevant to the current resolution of the ADC14 device. For example, say the ADC14 module is
setup with a 14-bit resolution and a positive reference of 2.5v (and a negative of 0v). In this case, if
the conversion result of 16383 would signify a value of 2.5v (if in unsigned) mode. A snippet of
code that converts the conversion result in the ADC register to a real life value can be seen in the
following:
/* Converts the ADC result (14-bit) to a float with respect to a 3.3v reference
*/
static float convertToFloat(uint16_t result)
{
int32_t temp;
if(0x8000 & result)
{
temp = (result >> 2) | 0xFFFFC000;
return ((temp * 3.3f) / 8191);
}
else
return ((result >> 2)*3.3f) / 8191;
}
It is important to note that when using floating point arithmetic, it is important to enable the devices
FPU (if available) to save CPU cycles and energy consumption.
2.5
Programming Example
The DriverLib package contains a variety of different code examples that demonstrate the usage
of the ADC14 module. These code examples are accessible under the examples/ folder of the
MSPWare release as well as through TI Resource Explorer if using Code Composer Studio.
These code examples provide a comprehensive list of use cases as well as practical applications
involving each module.
Below is a very brief code example showing how to configure the ADC14 module in single sample
mode. For a set of more detailed code examples, please refer to the code examples in the
examples/ directory of the MSPWare release:
/* Initializing ADC (MCLK/1/1) */
ADC14_enableModule();
ADC14_initModule(ADC_CLOCKSOURCE_MCLK,
0);
ADC_PREDIVIDER_1,
ADC_DIVIDER_1,
/* Configuring ADC Memory (ADC_MEM0 A0/A1) in repeat mode
* with use of external references */
ADC14_configureSingleSampleMode(ADC_MEM0, true);
ADC14_configureConversionMemory(ADC_MEM0,
ADC_VREFPOS_EXTPOS_VREFNEG_EXTNEG,
ADC_INPUT_A0, false);
/* Setting up GPIO pins as analog inputs (and references) */
GPIO_setAsPeripheralModuleFunctionInputPin(GPIO_PORT_P5,
GPIO_PIN7 | GPIO_PIN6 | GPIO_PIN5 | GPIO_PIN4, GPIO_TERTIARY_MODULE_FUNCTION);
/* Enabling sample timer in auto iteration mode and interrupts*/
ADC14_enableSampleTimer(ADC_AUTOMATIC_ITERATION);
ADC14_enableInterrupt(ADC_INT0);
/* Enabling Interrupts */
Interrupt_enableInterrupt(INT_ADC14);
Thu Jan 21 2016 12:34:41 AM
12
14-Bit Analog-to-Digital Converter (ADC14)
Interrupt_enableMaster();
/* Triggering the start of the sample */
ADC14_enableConversion();
ADC14_toggleConversionTrigger();
Thu Jan 21 2016 12:34:41 AM
13
14-Bit Analog-to-Digital Converter (ADC14)
2.6
Definitions
Functions
void ADC14_clearInterruptFlag (uint_fast64_t mask)
bool ADC14_configureConversionMemory (uint32_t memorySelect, uint32_t refSelect,
uint32_t channelSelect, bool differntialMode)
bool ADC14_configureMultiSequenceMode (uint32_t memoryStart, uint32_t memoryEnd,
bool repeatMode)
bool ADC14_configureSingleSampleMode (uint32_t memoryDestination, bool repeatMode)
bool ADC14_disableComparatorWindow (uint32_t memorySelect)
void ADC14_disableConversion (void)
void ADC14_disableInterrupt (uint_fast64_t mask)
bool ADC14_disableModule (void)
bool ADC14_disableReferenceBurst (void)
bool ADC14_disableSampleTimer (void)
bool ADC14_enableComparatorWindow (uint32_t memorySelect, uint32_t windowSelect)
bool ADC14_enableConversion (void)
void ADC14_enableInterrupt (uint_fast64_t mask)
void ADC14_enableModule (void)
bool ADC14_enableReferenceBurst (void)
bool ADC14_enableSampleTimer (uint32_t multiSampleConvert)
uint_fast64_t ADC14_getEnabledInterruptStatus (void)
uint_fast64_t ADC14_getInterruptStatus (void)
void ADC14_getMultiSequenceResult (uint16_t ∗res)
uint_fast32_t ADC14_getResolution (void)
uint_fast16_t ADC14_getResult (uint32_t memorySelect)
void ADC14_getResultArray (uint32_t memoryStart, uint32_t memoryEnd, uint16_t ∗res)
bool ADC14_initModule (uint32_t clockSource, uint32_t clockPredivider, uint32_t
clockDivider, uint32_t internalChannelMask)
bool ADC14_isBusy (void)
void ADC14_registerInterrupt (void(∗intHandler)(void))
bool ADC14_setComparatorWindowValue (uint32_t window, int16_t low, int16_t high)
bool ADC14_setPowerMode (uint32_t powerMode)
void ADC14_setResolution (uint32_t resolution)
bool ADC14_setResultFormat (uint32_t resultFormat)
bool ADC14_setSampleHoldTime (uint32_t firstPulseWidth, uint32_t secondPulseWidth)
bool ADC14_setSampleHoldTrigger (uint32_t source, bool invertSignal)
bool ADC14_toggleConversionTrigger (void)
void ADC14_unregisterInterrupt (void)
2.6.1
Detailed Description
The code for this module is contained in driverlib/adc14.c, with driverlib/adc14.h
containing the API declarations for use by applications.
Thu Jan 21 2016 12:34:41 AM
14
14-Bit Analog-to-Digital Converter (ADC14)
2.6.2
Function Documentation
2.6.2.1
void ADC14_clearInterruptFlag ( uint_fast64_t mask )
Clears the indicated ADCC interrupt sources.
Parameters
mask
is the bit mask of interrupts to clear. The ADC_INT0 through ADC_INT31 parameters
correspond to a completion event of the corresponding memory location. For example,
when the ADC_MEM0 location finishes a conversion cycle, the ADC_INT0 interrupt will
be set. Valid values are a bitwise OR of the following values:
ADC_INT0 through ADC_INT31
ADC_IN_INT - Interrupt enable for a conversion in the result register is either greater
than the ADCLO or lower than the ADCHI threshold.
ADC_LO_INT - Interrupt enable for the falling short of the lower limit interrupt of the
window comparator for the result register.
ADC_HI_INT - Interrupt enable for the exceeding the upper limit of the window comparator for the result register.
ADC_OV_INT - Interrupt enable for a conversion that is about to save to a memory
buffer that has not been read out yet.
ADC_TOV_INT -Interrupt enable for a conversion that is about to start before the
previous conversion has been completed.
ADC_RDY_INT -Interrupt enable for the local buffered reference ready signal.
Returns
NONE
2.6.2.2
bool ADC14_configureConversionMemory ( uint32_t memorySelect, uint32_t
refSelect, uint32_t channelSelect, bool differntialMode )
Configures an individual memory location for the ADC module.
Thu Jan 21 2016 12:34:41 AM
15
14-Bit Analog-to-Digital Converter (ADC14)
Parameters
memorySelect
is the individual ADC memory location to configure. If multiple memory locations want to
be configured with the same configuration, this value can be logically ORed together with
other values.
ADC_MEM0 through ADC_MEM31
refSelect
is the voltage reference to use for the selected memory spot. Possible values include:
ADC_VREFPOS_AVCC_VREFNEG_VSS [DEFAULT]
ADC_VREFPOS_INTBUF_VREFNEG_VSS
ADC_VREFPOS_EXTPOS_VREFNEG_EXTNEG
ADC_VREFPOS_EXTBUF_VREFNEG_EXTNEG
channelSelect
selects the channel to be used for ADC sampling. Note if differential mode is enabled,
the value sampled will be equal to the difference between the corresponding even/odd
memory locations. Possible values are:
ADC_INPUT_A0 through ADC_INPUT_A31
differntialMode
selects if the channel selected by the channelSelect will be configured in differential mode.
If this parameter is given as true, the configured channel will be paired with its neighbor in
differential mode. for example, if channel A0 or A1 is selected, the channel configured will
be the difference between A0 and A1. If A2 or A3 are selected, the channel configured
will be the difference between A2 and A3 (and so on). Users can enter true or false, or
one of the following values:
ADC_NONDIFFERENTIAL_INPUTS
ADC_DIFFERENTIAL_INPUTS
Returns
false if setting fails due to an in progress conversion
2.6.2.3
bool ADC14_configureMultiSequenceMode ( uint32_t memoryStart, uint32_t
memoryEnd, bool repeatMode )
Configures the ADC module to use a multiple memory sample scheme. This means that multiple
samples will consecutively take place and be stored in multiple memory locations. The first
sample/conversion will be placed in memoryStart, while the last sample will be stored in
memoryEnd. Each memory location should be configured individually using the
ADC14_configureConversionMemory function.
The ADC module can be started in "repeat" mode which will cause the ADC module to resume
sampling once the initial sample/conversion set is executed. For multi-sample mode, this means
that the sampling of the entire memory provided.
Thu Jan 21 2016 12:34:41 AM
16
14-Bit Analog-to-Digital Converter (ADC14)
Parameters
memoryStart
Memory location to store first sample/conversion value. Possible values include:
ADC_MEM0 through ADC_MEM31
memoryEnd
Memory location to store last sample. Possible values include:
ADC_MEM0 through ADC_MEM31
repeatMode
Specifies whether or not to repeat the conversion/sample cycle after the first round of
sample/conversions. Valid values are true or false.
Returns
false if setting fails due to an in progress conversion
2.6.2.4
bool ADC14_configureSingleSampleMode ( uint32_t memoryDestination, bool
repeatMode )
Configures the ADC module to use a a single ADC memory location for sampling/conversion. This
is used when only one channel might be needed for conversion, or where using a multiple
sampling scheme is not important.
The ADC module can be started in "repeat" mode which will cause the ADC module to resume
sampling once the initial sample/conversion set is executed. In single sample mode, this will cause
the ADC module to continuously sample into the memory destination provided.
Parameters
memoryDestination
repeatMode
Memory location to store sample/conversion value. Possible values include:
ADC_MEM0 through ADC_MEM31
Specifies whether or not to repeat the conversion/sample cycle after the first round of
sample/conversions
Returns
false if setting fails due to an in progress conversion
2.6.2.5
bool ADC14_disableComparatorWindow ( uint32_t memorySelect )
Disables the comparator window on the specified memory channels
Parameters
memorySelect
is the mask of memory locations to disable the comparator window for. This can be a
bitwise OR of the following values:
ADC_MEM0 through ADC_MEM31
Thu Jan 21 2016 12:34:41 AM
17
14-Bit Analog-to-Digital Converter (ADC14)
Returns
false if setting fails due to an in progress conversion
2.6.2.6
void ADC14_disableConversion ( void )
Halts conversion conversion of the ADC module. Note that the software bit for triggering
conversions will also be cleared with this function.
If multi-sequence conversion mode was enabled, the position of the last completed conversion can
be retrieved using ADCLastConversionMemoryGet
Returns
none
2.6.2.7
void ADC14_disableInterrupt ( uint_fast64_t mask )
Disables the indicated ADCC interrupt sources. Only the sources that are enabled can be
reflected to the processor interrupt; disabled sources have no effect on the processor. The
ADC_INT0 through ADC_INT31 parameters correspond to a completion event of the
corresponding memory location. For example, when the ADC_MEM0 location finishes a
conversion cycle, the ADC_INT0 interrupt will be set.
Parameters
mask
is the bit mask of interrupts to disable. Valid values are a bitwise OR of the following
values:
ADC_INT0 through ADC_INT31
ADC_IN_INT - Interrupt enable for a conversion in the result register is either greater
than the ADCLO or lower than the ADCHI threshold.
ADC_LO_INT - Interrupt enable for the falling short of the lower limit interrupt of the
window comparator for the result register.
ADC_HI_INT - Interrupt enable for the exceeding the upper limit of the window comparator for the result register.
ADC_OV_INT - Interrupt enable for a conversion that is about to save to a memory
buffer that has not been read out yet.
ADC_TOV_INT -Interrupt enable for a conversion that is about to start before the
previous conversion has been completed.
ADC_RDY_INT -Interrupt enable for the local buffered reference ready signal.
Returns
NONE
2.6.2.8
bool ADC14_disableModule ( void )
Disables the ADC block.
This will disable operation of the ADC block.
Thu Jan 21 2016 12:34:41 AM
18
14-Bit Analog-to-Digital Converter (ADC14)
Returns
false if user is trying to disable during active conversion
2.6.2.9
bool ADC14_disableReferenceBurst ( void )
Disables the "on-demand" activity of the voltage reference register.
Returns
false if setting fails due to an in progress conversion
2.6.2.10 bool ADC14_disableSampleTimer ( void )
Disables SAMPCON from being sourced from the sample timer.
Returns
false if the initialization fails due to an in progress conversion
2.6.2.11 bool ADC14_enableComparatorWindow ( uint32_t memorySelect, uint32_t
windowSelect )
Enables the specified mask of memory channels to use the specified comparator window. THe
ADCC module has two different comparator windows that can be set with this function.
Parameters
memorySelect
is the mask of memory locations to enable the comparator window for. This can be a
bitwise OR of the following values:
ADC_MEM0 through ADC_MEM31
windowSelect
Memory location to store sample/conversion value.
COMP_WINDOW0 [DEFAULT] ADCOMP_WINDOW1
Possible values include: AD-
Returns
false if setting fails due to an in progress conversion
2.6.2.12 bool ADC14_enableConversion ( void )
Enables conversion of ADC data. Note that this only enables conversion. To trigger the
conversion, you will have to call the ADC14_toggleConversionTrigger or use the source trigger
configured in ADC14_setSampleHoldTrigger.
Returns
false if setting fails due to an in progress conversion
Thu Jan 21 2016 12:34:41 AM
19
14-Bit Analog-to-Digital Converter (ADC14)
2.6.2.13 void ADC14_enableInterrupt ( uint_fast64_t mask )
Enables the indicated ADCC interrupt sources. The ADC_INT0 through ADC_INT31 parameters
correspond to a completion event of the corresponding memory location. For example, when the
ADC_MEM0 location finishes a conversion cycle, the ADC_INT0 interrupt will be set.
Parameters
mask
is the bit mask of interrupts to enable. Valid values are a bitwise OR of the following
values:
ADC_INT0 through ADC_INT31
ADC_IN_INT - Interrupt enable for a conversion in the result register is either greater
than the ADCLO or lower than the ADCHI threshold.
ADC_LO_INT - Interrupt enable for the falling short of the lower limit interrupt of the
window comparator for the result register.
ADC_HI_INT - Interrupt enable for the exceeding the upper limit of the window comparator for the result register.
ADC_OV_INT - Interrupt enable for a conversion that is about to save to a memory
buffer that has not been read out yet.
ADC_TOV_INT -Interrupt enable for a conversion that is about to start before the
previous conversion has been completed.
ADC_RDY_INT -Interrupt enable for the local buffered reference ready signal.
Returns
NONE
2.6.2.14 void ADC14_enableModule ( void )
Enables the ADC block.
This will enable operation of the ADC block.
Returns
none.
2.6.2.15 bool ADC14_enableReferenceBurst ( void )
Enables the "on-demand" activity of the voltage reference register. If this setting is enabled, the
internal voltage reference buffer will only be updated during a sample or conversion cycle. This is
used to optimize power consumption.
Returns
false if setting fails due to an in progress conversion
Thu Jan 21 2016 12:34:41 AM
20
14-Bit Analog-to-Digital Converter (ADC14)
2.6.2.16 bool ADC14_enableSampleTimer ( uint32_t multiSampleConvert )
Enables SAMPCON to be sourced from the sampling timer and to configures multi sample and
conversion mode.
Thu Jan 21 2016 12:34:41 AM
21
14-Bit Analog-to-Digital Converter (ADC14)
Parameters
multiSampleConvert
- Switches between manual and automatic iteration when using the sample timer. Valid
values are:
ADC_MANUAL_ITERATION The user will have to manually set the SHI signal (
usually by ADC14_toggleConversionTrigger ) at the end of each sample/conversion
cycle.
ADC_AUTOMATIC_ITERATION After one sample/convert is finished, the ADC module will automatically continue on to the next sample
Returns
false if the initialization fails due to an in progress conversion
2.6.2.17 uint_fast64_t ADC14_getEnabledInterruptStatus ( void )
Returns the status of a the ADC interrupt register masked with the enabled interrupts. This
function is useful to call in ISRs to get a list of pending interrupts that are actually enabled and
could have caused the ISR. The ADC_INT0 through ADC_INT31 parameters correspond to a
completion event of the corresponding memory location. For example, when the ADC_MEM0
location finishes a conversion cycle, the ADC_INT0
Returns
The interrupt status. Value is a bitwise OR of the following values:
ADC_INT0 through ADC_INT31
ADC_IN_INT - Interrupt enable for a conversion in the result register is either greater
than the ADCLO or lower than the ADCHI threshold.
ADC_LO_INT - Interrupt enable for the falling short of the lower limit interrupt of the
window comparator for the result register.
ADC_HI_INT - Interrupt enable for the exceeding the upper limit of the window
comparator for the result register.
ADC_OV_INT - Interrupt enable for a conversion that is about to save to a memory
buffer that has not been read out yet.
ADC_TOV_INT -Interrupt enable for a conversion that is about to start before the
previous conversion has been completed.
ADC_RDY_INT -Interrupt enable for the local buffered reference ready signal.
References ADC14_getInterruptStatus().
2.6.2.18 uint_fast64_t ADC14_getInterruptStatus ( void )
Returns the status of a the ADC interrupt register. The ADC_INT0 through ADC_INT31
parameters correspond to a completion event of the corresponding memory location. For example,
when the ADC_MEM0 location finishes a conversion cycle, the ADC_INT0 interrupt will be set.
Thu Jan 21 2016 12:34:41 AM
22
14-Bit Analog-to-Digital Converter (ADC14)
Returns
The interrupt status. Value is a bitwise OR of the following values:
ADC_INT0 through ADC_INT31
ADC_IN_INT - Interrupt enable for a conversion in the result register is either greater
than the ADCLO or lower than the ADCHI threshold.
ADC_LO_INT - Interrupt enable for the falling short of the lower limit interrupt of the
window comparator for the result register.
ADC_HI_INT - Interrupt enable for the exceeding the upper limit of the window
comparator for the result register.
ADC_OV_INT - Interrupt enable for a conversion that is about to save to a memory
buffer that has not been read out yet.
ADC_TOV_INT -Interrupt enable for a conversion that is about to start before the
previous conversion has been completed.
ADC_RDY_INT -Interrupt enable for the local buffered reference ready signal.
Referenced by ADC14_getEnabledInterruptStatus().
2.6.2.19 void ADC14_getMultiSequenceResult ( uint16_t ∗ res )
Returns the conversion results of the currently configured multi-sequence conversion. If a
multi-sequence conversion has not happened, this value is unreliable. Note that it is up to the user
to verify the integrity of and proper size of the array being passed. If there are 16 multi-sequence
results, and an array with only 4 elements allocated is passed, invalid memory settings will occur
Parameters
res
conversion result of the last multi-sequence sample in an array of unsigned 16-bit integers
Returns
None
2.6.2.20 uint_fast32_t ADC14_getResolution ( void )
Gets the resolution of the ADC module.
Returns
Resolution of the ADC module
ADC_8BIT (10 clock cycle conversion time)
ADC_10BIT (12 clock cycle conversion time)
ADC_12BIT (14 clock cycle conversion time)
ADC_14BIT (16 clock cycle conversion time)
2.6.2.21 uint_fast16_t ADC14_getResult ( uint32_t memorySelect )
Returns the conversion result for the specified memory channel in the format assigned by the
ADC14_setResultFormat (unsigned binary by default) function.
Thu Jan 21 2016 12:34:41 AM
23
14-Bit Analog-to-Digital Converter (ADC14)
Parameters
memorySelect
is the memory location to get the conversion result. Valid values are:
ADC_MEM0 through ADC_MEM31
Returns
conversion result of specified memory channel
2.6.2.22 void ADC14_getResultArray ( uint32_t memoryStart, uint32_t memoryEnd,
uint16_t ∗ res )
Returns the conversion results of the specified ADC memory locations. Note that it is up to the
user to verify the integrity of and proper size of the array being passed. If there are 16
multi-sequence results, and an array with only 4 elements allocated is passed, invalid memory
settings will occur. This function is inclusive.
Parameters
memoryStart
is the memory location to get the conversion result. Valid values are:
ADC_MEM0 through ADC_MEM31
memoryEnd
is the memory location to get the conversion result. Valid values are:
ADC_MEM0 through ADC_MEM31
res
conversion result of the last multi-sequence sample in an array of unsigned 16-bit integers
Returns
None
2.6.2.23 bool ADC14_initModule ( uint32_t clockSource, uint32_t clockPredivider,
uint32_t clockDivider, uint32_t internalChannelMask )
Initializes the ADC module and sets up the clock system divider/pre-divider. This initialization
function will also configure the internal/external signal mapping.
Thu Jan 21 2016 12:34:41 AM
24
14-Bit Analog-to-Digital Converter (ADC14)
Note
A call to this function while active ADC conversion is happening is an invalid case and will
result in a false value being returned.
Parameters
clockSource
The clock source to use for the ADC module.
ADC_CLOCKSOURCE_ADCOSC [DEFAULT]
ADC_CLOCKSOURCE_SYSOSC
ADC_CLOCKSOURCE_ACLK
ADC_CLOCKSOURCE_MCLK
ADC_CLOCKSOURCE_SMCLK
ADC_CLOCKSOURCE_HSMCLK
clockPredivider
Divides the given clock source before feeding it into the main clock divider. Valid values
are:
ADC_PREDIVIDER_1 [DEFAULT]
ADC_PREDIVIDER_4
ADC_PREDIVIDER_32
ADC_PREDIVIDER_64
clockDivider
Divides the pre-divided clock source Valid values are
ADC_DIVIDER_1 [Default value]
ADC_DIVIDER_2
ADC_DIVIDER_3
ADC_DIVIDER_4
ADC_DIVIDER_5
ADC_DIVIDER_6
ADC_DIVIDER_7
ADC_DIVIDER_8
Thu Jan 21 2016 12:34:41 AM
25
14-Bit Analog-to-Digital Converter (ADC14)
internalChannelMask
Configures the internal/external pin mappings for the ADC modules. This setting determines if the given ADC channel or component is mapped to an external pin (default), or
routed to an internal component. This parameter is a bit mask where a logical high value
will switch the component to the internal routing. For a list of internal routings, please refer
to the device specific data sheet. Valid values are a logical OR of the following values:
ADC_MAPINTCH3
ADC_MAPINTCH2
ADC_MAPINTCH1
ADC_MAPINTCH0
ADC_TEMPSENSEMAP
ADC_BATTMAP
ADC_NOROUTE If internalChannelMask is not desired, pass ADC_NOROUTE in
lieu of this parameter.
Returns
false if the initialization fails due to an in progress conversion
2.6.2.24 bool ADC14_isBusy ( void )
Returns a boolean value that tells if a conversion/sample is in progress
Returns
true if conversion is active, false otherwise
2.6.2.25 void ADC14_registerInterrupt ( void(∗)(void) intHandler )
Registers an interrupt handler for the ADC interrupt.
Parameters
intHandler
is a pointer to the function to be called when the ADC interrupt occurs.
This function registers the handler to be called when an ADC interrupt occurs. This function
enables the global interrupt in the interrupt controller; specific ADC14 interrupts must be enabled
via ADC14_enableInterrupt(). It is the interrupt handler’s responsibility to clear the interrupt source
via ADC14_clearInterruptFlag().
See Also
Interrupt_registerInterrupt() for important information about registering interrupt handlers.
Returns
None.
References Interrupt_enableInterrupt(), and Interrupt_registerInterrupt().
Thu Jan 21 2016 12:34:41 AM
26
14-Bit Analog-to-Digital Converter (ADC14)
2.6.2.26 bool ADC14_setComparatorWindowValue ( uint32_t window, int16_t low, int16_t
high )
Sets the lower and upper limits of the specified window comparator. Note that this function will
truncate values based of the resolution/data format configured. If the ADC is operating in 10-bit
mode, and a 12-bit value is passed into this function the most significant 2 bits will be truncated.
The parameters provided to this function for the upper and lower threshold depend on the current
resolution for the ADC. For example, if configured in 12-bit mode, a 12-bit resolution is the
maximum that can be provided for the window. If in 2’s complement mode, Bit 15 is used as the
MSB.
Parameters
window
low
high
Memory location to store sample/conversion value.
Possible values include:
ADC_COMP_WINDOW0 [DEFAULT] ADC_COMP_WINDOW1
is the lower limit of the window comparator
is the upper limit of the window comparator
Returns
false if setting fails due to an in progress conversion
2.6.2.27 bool ADC14_setPowerMode ( uint32_t powerMode )
Sets the power mode of the ADC module. A more aggressive power mode will restrict the number
of samples per second for sampling while optimizing power consumption. Ideally, if power
consumption is a concern, this value should be set to the most restrictive setting that satisfies your
sampling requirement.
Parameters
adcPowerMode
is the power mode to set. Valid values are:
ADC_UNRESTRICTED_POWER_MODE (no restriction)
ADC_LOW_POWER_MODE (500ksps restriction)
ADC_ULTRA_LOW_POWER_MODE (200ksps restriction)
ADC_EXTREME_LOW_POWER_MODE (50ksps restriction)
Returns
false if setting fails due to an in progress conversion
2.6.2.28 void ADC14_setResolution ( uint32_t resolution )
Sets the resolution of the ADC module. The default resolution is 12-bit, however for power
consumption concerns this can be limited to a lower resolution
Thu Jan 21 2016 12:34:41 AM
27
14-Bit Analog-to-Digital Converter (ADC14)
Parameters
resolution
Resolution of the ADC module
ADC_8BIT (10 clock cycle conversion time)
ADC_10BIT (12 clock cycle conversion time)
ADC_12BIT (14 clock cycle conversion time)
ADC_14BIT (16 clock cycle conversion time)[DEFAULT]
Returns
none
2.6.2.29 bool ADC14_setResultFormat ( uint32_t resultFormat )
Switches between a binary unsigned data format and a signed 2’s complement data format.
Parameters
resultFormat
Format for result to conversion results.
Possible
ADC_UNSIGNED_BINARY [DEFAULT] ADC_SIGNED_BINARY
values
Returns
false if setting fails due to an in progress conversion
2.6.2.30 bool ADC14_setSampleHoldTime ( uint32_t firstPulseWidth, uint32_t
secondPulseWidth )
Sets the sample/hold time for the specified memory register range. The duration of time required
for a sample differs depending on the user’s hardware configuration.
There are two values in the ADCC module. The first value controls ADC memory locations
ADC_MEMORY_0 through ADC_MEMORY_7 and ADC_MEMORY_24 through
ADC_MEMORY_31, while the second value controls memory locations ADC_MEMORY_8
through ADC_MEMORY_23.
Thu Jan 21 2016 12:34:41 AM
28
include:
14-Bit Analog-to-Digital Converter (ADC14)
Parameters
firstPulseWidth
Pulse width of the first pulse in ADCCLK cycles Possible values must be one of the following:
ADC_PULSE_WIDTH_4 [DEFAULT]
ADC_PULSE_WIDTH_8
ADC_PULSE_WIDTH_16
ADC_PULSE_WIDTH_32
ADC_PULSE_WIDTH_64
ADC_PULSE_WIDTH_96
ADC_PULSE_WIDTH_128
ADC_PULSE_WIDTH_192
secondPulseWidth
Pulse width of the second pulse in ADCCLK cycles. Possible values must be one of the
following:
ADC_PULSE_WIDTH_4 [DEFAULT]
ADC_PULSE_WIDTH_8
ADC_PULSE_WIDTH_16
ADC_PULSE_WIDTH_32
ADC_PULSE_WIDTH_64
ADC_PULSE_WIDTH_96
ADC_PULSE_WIDTH_128
ADC_PULSE_WIDTH_192
Returns
false if setting fails due to an in progress conversion
2.6.2.31 bool ADC14_setSampleHoldTrigger ( uint32_t source, bool invertSignal )
Sets the source for the trigger of the ADC module. By default, this value is configured to a
software source (the ADCSC bit), however depending on the specific device the trigger can be set
to different sources (for example, a timer output). These sources vary from part to part and the
user should refer to the device specific datasheet.
Thu Jan 21 2016 12:34:41 AM
29
14-Bit Analog-to-Digital Converter (ADC14)
Parameters
source
Trigger source for sampling. Possible values include:
ADC_TRIGGER_ADCSC [DEFAULT]
ADC_TRIGGER_SOURCE1
ADC_TRIGGER_SOURCE2
ADC_TRIGGER_SOURCE3
ADC_TRIGGER_SOURCE4
ADC_TRIGGER_SOURCE5
ADC_TRIGGER_SOURCE6
ADC_TRIGGER_SOURCE7
invertSignal
When set to true, will invert the trigger signal to a falling edge. When false, will use a rising
edge.
Returns
false if setting fails due to an in progress conversion
2.6.2.32 bool ADC14_toggleConversionTrigger ( void )
Toggles the trigger for conversion of the ADC module by toggling the trigger software bit. Note that
this will cause the ADC to start conversion regardless if the software bit was set as the trigger
using ADC14_setSampleHoldTrigger.
Returns
false if setting fails due to an in progress conversion
2.6.2.33 void ADC14_unregisterInterrupt ( void )
Unregisters the interrupt handler for the ADCC module.
This function unregisters the handler to be called when an ADCC interrupt occurs. This function
also masks off the interrupt in the interrupt controller so that the interrupt handler no longer is
called.
See Also
Interrupt_registerInterrupt() for important information about registering interrupt handlers.
Returns
None.
References Interrupt_disableInterrupt(), and Interrupt_unregisterInterrupt().
Thu Jan 21 2016 12:34:41 AM
30
Advanced Encryption Standard 256 Module (AES256)
3
Advanced Encryption Standard 256 Module
(AES256)
Module Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
Key Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .29
Encryption/Decryption Cycle Time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
Programming Example . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
3.1
Module Operation
The AES256 accelerator module performs encryption and decryption of 128-bit data with 128-bit
keys according to the advanced encryption standard (AES256) (FIPS PUB 197) in hardware.
3.2
Key Features
The key features of the AES256 module include:
Encryption and decryption according to AES256 FIPS PUB 197 with 128-bit key
On-the-fly key expansion for encryption and decryption
Off-line key generation for decryption
Byte and word access to key, input, and output data
AES256 ready interrupt flag
The AES256256 accelerator module performs encryption and decryption of 128-bit data with
128-/192-/256-bit keys according to the advanced encryption standard (AES256) (FIPS PUB 197)
in hardware.
Thu Jan 21 2016 12:34:41 AM
31
Advanced Encryption Standard 256 Module (AES256)
3.3
Encryption/Decryption Cycle Times
The the AES256 accelerator decryption/encryption cycle counts are as follows:
AES256 encryption
128 bit - 168 cycles
192 bit - 204 cycles
256 bit - 234 cycles
AES256 decryption:
128 bit - 168 cycles
192 bit - 206 cycles
256 bit - 234 cycles
3.4
Programming Example
The DriverLib package contains a variety of different code examples that demonstrate the usage
of the AES256 module. These code examples are accessible under the examples/ folder of the
MSPWare release as well as through TI Resource Explorer if using Code Composer Studio.
Below is a simple code example of how to encrypt/decrypt data using a cipher key with the
AES256 module
/* Load a cipher key to module */
MAP_AES256_setCipherKey(AES256_BASE,
CipherKey,
AES256_KEYLENGTH_256BIT);
/* Encrypt data with preloaded cipher key */
MAP_AES256_encryptData(AES256_BASE, Data, DataAESencrypted);
/* Load a decipher key to module */
MAP_AES256_setDecipherKey(AES256_BASE,
CipherKey, AES256_KEYLENGTH_256BIT);
/* Decrypt data with keys that were generated during encryption - takes
214 MCLK cyles. This function will generate all round keys needed for
decryption first and then the encryption process starts */
MAP_AES256_decryptData(AES256_BASE, DataAESencrypted, DataAESdecrypted);
Thu Jan 21 2016 12:34:41 AM
32
Advanced Encryption Standard 256 Module (AES256)
3.5
Definitions
Functions
void AES256_clearErrorFlag (uint32_t moduleInstance)
void AES256_clearInterruptFlag (uint32_t moduleInstance)
void AES256_decryptData (uint32_t moduleInstance, const uint8_t ∗data, uint8_t
∗decryptedData)
void AES256_disableInterrupt (uint32_t moduleInstance)
void AES256_enableInterrupt (uint32_t moduleInstance)
void AES256_encryptData (uint32_t moduleInstance, const uint8_t ∗data, uint8_t
∗encryptedData)
bool AES256_getDataOut (uint32_t moduleInstance, uint8_t ∗outputData)
uint32_t AES256_getErrorFlagStatus (uint32_t moduleInstance)
uint32_t AES256_getInterruptFlagStatus (uint32_t moduleInstance)
uint32_t AES256_getInterruptStatus (uint32_t moduleInstance)
bool AES256_isBusy (uint32_t moduleInstance)
void AES256_registerInterrupt (uint32_t moduleInstance, void(∗intHandler)(void))
void AES256_reset (uint32_t moduleInstance)
bool AES256_setCipherKey (uint32_t moduleInstance, const uint8_t ∗cipherKey,
uint_fast16_t keyLength)
bool AES256_setDecipherKey (uint32_t moduleInstance, const uint8_t ∗cipherKey,
uint_fast16_t keyLength)
void AES256_startDecryptData (uint32_t moduleInstance, const uint8_t ∗data)
void AES256_startEncryptData (uint32_t moduleInstance, const uint8_t ∗data)
bool AES256_startSetDecipherKey (uint32_t moduleInstance, const uint8_t ∗cipherKey,
uint_fast16_t keyLength)
void AES256_unregisterInterrupt (uint32_t moduleInstance)
3.5.1
Detailed Description
The code for this module is contained in driverlib/aes256.c and
driverlib/legacy/MSP432xx/legacy_aes256.c, with driverlib/aes256.h and
driverlib/legacy/MSP432xx/legacy_aes256.h containing the API declarations for use by
applications.
Thu Jan 21 2016 12:34:41 AM
33
Advanced Encryption Standard 256 Module (AES256)
3.5.2
Function Documentation
3.5.2.1
void AES256_clearErrorFlag ( uint32_t moduleInstance )
Clears the AES256 error flag.
Parameters
moduleInstance
is the base address of the AES256 module.
Modified bits are AESERRFG of AESACTL0 register.
Returns
None
3.5.2.2
void AES256_clearInterruptFlag ( uint32_t moduleInstance )
Clears the AES256 ready interrupt flag.
Parameters
moduleInstance
is the base address of the AES256 module.
Modified bits are AESRDYIFG of AESACTL0 register.
Returns
None
3.5.2.3
void AES256_decryptData ( uint32_t moduleInstance, const uint8_t ∗ data,
uint8_t ∗ decryptedData )
Decrypts a block of data using the AES256 module.
This function requires a pregenerated decryption key. A key can be loaded and pregenerated by
using function AES256_setDecipherKey() or AES256_startSetDecipherKey(). The decryption
takes 167 MCLK.
Parameters
moduleInstance
data
decryptedData
is the base address of the AES256 module.
is a pointer to an uint8_t array with a length of 16 bytes that contains encrypted data to be
decrypted.
is a pointer to an uint8_t array with a length of 16 bytes in that the decrypted data will be
written.
Returns
None
3.5.2.4
void AES256_disableInterrupt ( uint32_t moduleInstance )
Disables AES256 ready interrupt.
Thu Jan 21 2016 12:34:41 AM
34
Advanced Encryption Standard 256 Module (AES256)
Parameters
moduleInstance
is the base address of the AES256 module.
Modified bits are AESRDYIE of AESACTL0 register.
Returns
None
3.5.2.5
void AES256_enableInterrupt ( uint32_t moduleInstance )
Enables AES256 ready interrupt.
Parameters
moduleInstance
is the base address of the AES256 module.
Modified bits are AESRDYIE of AESACTL0 register.
Returns
None
3.5.2.6
void AES256_encryptData ( uint32_t moduleInstance, const uint8_t ∗ data,
uint8_t ∗ encryptedData )
Encrypts a block of data using the AES256 module.
The cipher key that is used for encryption should be loaded in advance by using function
AES256_setCipherKey()
Parameters
moduleInstance
data
encryptedData
is the base address of the AES256 module.
is a pointer to an uint8_t array with a length of 16 bytes that contains data to be encrypted.
is a pointer to an uint8_t array with a length of 16 bytes in that the encrypted data will be
written.
Returns
None
3.5.2.7
bool AES256_getDataOut ( uint32_t moduleInstance, uint8_t ∗ outputData )
Reads back the output data from AES256 module.
This function is meant to use after an encryption or decryption process that was started and
finished by initiating an interrupt by use of AES256_startEncryptData or
AES256_startDecryptData functions.
Thu Jan 21 2016 12:34:41 AM
35
Advanced Encryption Standard 256 Module (AES256)
Parameters
moduleInstance
outputData
is the base address of the AES256 module.
is a pointer to an uint8_t array with a length of 16 bytes in that the data will be written.
Returns
true if data is valid, otherwise false
3.5.2.8
uint32_t AES256_getErrorFlagStatus ( uint32_t moduleInstance )
Gets the AES256 error flag status.
Parameters
moduleInstance
is the base address of the AES256 module.
Returns
One of the following:
AES256_ERROR_OCCURRED
AES256_NO_ERROR
indicating the error flag status
3.5.2.9
uint32_t AES256_getInterruptFlagStatus ( uint32_t moduleInstance )
Gets the AES256 ready interrupt flag status.
Parameters
moduleInstance
is the base address of the AES256 module.
Returns
One of the following:
AES256_READY_INTERRUPT
AES256_NOTREADY_INTERRUPT
indicating the status of the AES256 ready status
Referenced by AES256_getInterruptStatus().
3.5.2.10 uint32_t AES256_getInterruptStatus ( uint32_t moduleInstance )
Returns the current interrupt flag for the peripheral.
Parameters
moduleInstance
Instance of the AES256 module
Returns
The currently triggered interrupt flag for the module.
References AES256_getInterruptFlagStatus().
Thu Jan 21 2016 12:34:41 AM
36
Advanced Encryption Standard 256 Module (AES256)
3.5.2.11 bool AES256_isBusy ( uint32_t moduleInstance )
Gets the AES256 module busy status.
Thu Jan 21 2016 12:34:41 AM
37
Advanced Encryption Standard 256 Module (AES256)
Parameters
moduleInstance
is the base address of the AES256 module.
Returns
true if busy, false otherwise
3.5.2.12 void AES256_registerInterrupt ( uint32_t moduleInstance, void(∗)(void)
intHandler )
Registers an interrupt handler for the AES interrupt.
Parameters
moduleInstance
intHandler
Instance of the AES256 module
is a pointer to the function to be called when the AES interrupt occurs.
This function registers the handler to be called when a AES interrupt occurs. This function enables
the global interrupt in the interrupt controller; specific AES interrupts must be enabled via
AES256_enableInterrupt(). It is the interrupt handler’s responsibility to clear the interrupt source
via AES256_clearInterrupt().
Returns
None.
References Interrupt_enableInterrupt(), and Interrupt_registerInterrupt().
3.5.2.13 void AES256_reset ( uint32_t moduleInstance )
Resets AES256 Module immediately.
Parameters
moduleInstance
is the base address of the AES256 module.
Modified bits are AESSWRST of AESACTL0 register.
Returns
None
3.5.2.14 bool AES256_setCipherKey ( uint32_t moduleInstance, const uint8_t ∗
cipherKey, uint_fast16_t keyLength )
Loads a 128, 192 or 256 bit cipher key to AES256 module.
Thu Jan 21 2016 12:34:41 AM
38
Advanced Encryption Standard 256 Module (AES256)
Parameters
moduleInstance
cipherKey
keyLength
is the base address of the AES256 module.
is a pointer to an uint8_t array with a length of 16 bytes that contains a 128 bit cipher key.
is the length of the key. Valid values are:
AES256_KEYLENGTH_128BIT
AES256_KEYLENGTH_192BIT
AES256_KEYLENGTH_256BIT
Returns
true if set correctly, false otherwise
3.5.2.15 bool AES256_setDecipherKey ( uint32_t moduleInstance, const uint8_t ∗
cipherKey, uint_fast16_t keyLength )
Sets the decipher key.
The API AES256_startSetDecipherKey or AES256_setDecipherKey must be invoked before
invoking AES256_startDecryptData.
Parameters
moduleInstance
cipherKey
keyLength
is the base address of the AES256 module.
is a pointer to an uint8_t array with a length of 16 bytes that contains a 128 bit cipher key.
is the length of the key. Valid values are:
AES256_KEYLENGTH_128BIT
AES256_KEYLENGTH_192BIT
AES256_KEYLENGTH_256BIT
Returns
true if set, false otherwise
3.5.2.16 void AES256_startDecryptData ( uint32_t moduleInstance, const uint8_t ∗ data )
Decypts a block of data using the AES256 module.
This is the non-blocking equivalant of AES256_decryptData(). This function requires a
pregenerated decryption key. A key can be loaded and pregenerated by using function
AES256_setDecipherKey() or AES256_startSetDecipherKey(). The decryption takes 167 MCLK. It
is recommended to use interrupt to check for procedure completion then use the
AES256_getDataOut() API to retrieve the decrypted data.
Parameters
Thu Jan 21 2016 12:34:41 AM
39
Advanced Encryption Standard 256 Module (AES256)
moduleInstance
data
is the base address of the AES256 module.
is a pointer to an uint8_t array with a length of 16 bytes that contains encrypted data to be
decrypted.
Returns
None
3.5.2.17 void AES256_startEncryptData ( uint32_t moduleInstance, const uint8_t ∗ data )
Starts an encryption process on the AES256 module.
The cipher key that is used for decryption should be loaded in advance by using function
AES256_setCipherKey(). This is a non-blocking equivalent pf AES256_encryptData(). It is
recommended to use the interrupt functionality to check for procedure completion then use the
AES256_getDataOut() API to retrieve the encrypted data.
Parameters
moduleInstance
data
is the base address of the AES256 module.
is a pointer to an uint8_t array with a length of 16 bytes that contains data to be encrypted.
Returns
None
3.5.2.18 bool AES256_startSetDecipherKey ( uint32_t moduleInstance, const uint8_t ∗
cipherKey, uint_fast16_t keyLength )
Sets the decipher key.
The API AES256_startSetDecipherKey() or AES256_setDecipherKey() must be invoked before
invoking AES256_startDecryptData.
Parameters
moduleInstance
cipherKey
keyLength
is the base address of the AES256 module.
is a pointer to an uint8_t array with a length of 16 bytes that contains a 128 bit cipher key.
is the length of the key. Valid values are:
AES256_KEYLENGTH_128BIT
AES256_KEYLENGTH_192BIT
AES256_KEYLENGTH_256BIT
Returns
true if set correctly, false otherwise
3.5.2.19 void AES256_unregisterInterrupt ( uint32_t moduleInstance )
Unregisters the interrupt handler for the AES interrupt
Thu Jan 21 2016 12:34:41 AM
40
Advanced Encryption Standard 256 Module (AES256)
Parameters
moduleInstance
Instance of the AES256 module
This function unregisters the handler to be called when AES interrupt occurs. This function also
masks off the interrupt in the interrupt controller so that the interrupt handler no longer is called.
See Also
Interrupt_registerInterrupt() for important information about registering interrupt handlers.
Returns
None.
References Interrupt_disableInterrupt(), and Interrupt_unregisterInterrupt().
Thu Jan 21 2016 12:34:41 AM
41
Analog Comparator (COMP_E)
4
Analog Comparator (COMP_E)
Module Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
Programming Example . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .??
Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
4.1
Module Operation
The Comparator (Comp) API provides a set of functions for using the MSPWare COMP_E
modules. Functions are provided to initialize the COMP_E modules, setup reference voltages for
input, and manage interrupts for the COMP_E modules.
The COMP_E module provides the ability to compare two analog signals and use the output in
software and on an output pin. The output represents whether the signal on the positive terminal is
higher than the signal on the negative terminal. The COMP_E moduke may be used to generate a
hysteresis. There are 16 different inputs that can be used, as well as the ability to short 2 input
together. The COMP_E module also has control over the REF_A module to generate a reference
voltage as an input.
The COMP_E module can generate multiple interrupts. An interrupt may be asserted for the
output, with separate interrupts on whether the output rises, or falls.
Thu Jan 21 2016 12:34:41 AM
42
Analog Comparator (COMP_E)
4.2
Programming Example
The DriverLib package contains a variety of different code examples that demonstrate the usage
of the COMP_E module. These code examples are accessible under the examples/ folder of the
MSPWare release as well as through TI Resource Explorer if using Code Composer Studio.
These code examples provide a comprehensive list of use cases as well as practical applications
involving each module.
Below is a simple example of how to setup the COMP_E module to setup a comparator window
with a Vcompare of 1.2v using the internal reference.
First, below is an example of setting up the COMP_E module configuration structure:
/* Comparator configuration structure */
const COMP_E_Config compConfig =
{
COMP_E_VREF,
COMP_E_INPUT7,
COMP_E_FILTEROUTPUT_DLYLVL4,
COMP_E_NORMALOUTPUTPOLARITY
};
// Positive Input Terminal
// Negative Input Terminal
// Delay Level 4 Filter
// Normal Output Polarity
Below are the actual DriverLib calls to configure/setup the Comp module:
Thu Jan 21 2016 12:34:41 AM
43
Analog Comparator (COMP_E)
4.3
Definitions
Data Structures
struct _COMP_E_Config
Functions
void COMP_E_clearInterruptFlag (uint32_t comparator, uint_fast16_t mask)
void COMP_E_disableInputBuffer (uint32_t comparator, uint_fast16_t inputPort)
void COMP_E_disableInterrupt (uint32_t comparator, uint_fast16_t mask)
void COMP_E_disableModule (uint32_t comparator)
void COMP_E_enableInputBuffer (uint32_t comparator, uint_fast16_t inputPort)
void COMP_E_enableInterrupt (uint32_t comparator, uint_fast16_t mask)
void COMP_E_enableModule (uint32_t comparator)
uint_fast16_t COMP_E_getEnabledInterruptStatus (uint32_t comparator)
uint_fast16_t COMP_E_getInterruptStatus (uint32_t comparator)
bool COMP_E_initModule (uint32_t comparator, const COMP_E_Config ∗config)
uint8_t COMP_E_outputValue (uint32_t comparator)
void COMP_E_registerInterrupt (uint32_t comparator, void(∗intHandler)(void))
void COMP_E_setInterruptEdgeDirection (uint32_t comparator, uint_fast8_t edgeDirection)
void COMP_E_setPowerMode (uint32_t comparator, uint_fast16_t powerMode)
void COMP_E_setReferenceAccuracy (uint32_t comparator, uint_fast16_t
referenceAccuracy)
void COMP_E_setReferenceVoltage (uint32_t comparator, uint_fast16_t
supplyVoltageReferenceBase, uint_fast16_t lowerLimitSupplyVoltageFractionOf32,
uint_fast16_t upperLimitSupplyVoltageFractionOf32)
void COMP_E_shortInputs (uint32_t comparator)
void COMP_E_swapIO (uint32_t comparator)
void COMP_E_toggleInterruptEdgeDirection (uint32_t comparator)
void COMP_E_unregisterInterrupt (uint32_t comparator)
void COMP_E_unshortInputs (uint32_t comparator)
4.3.1
Detailed Description
The code for this module is contained in driverlib/comp_e.c, with driverlib/comp_e.h
containing the API declarations for use by applications.
Thu Jan 21 2016 12:34:41 AM
44
Analog Comparator (COMP_E)
4.3.2
Function Documentation
4.3.2.1
void COMP_E_clearInterruptFlag ( uint32_t comparator, uint_fast16_t mask )
Clears Comparator interrupt flags.
Parameters
comparator
is the instance of the Comparator module. Valid parameters vary from part to part, but
can include:
COMP_E0_BASE
COMP_E1_BASE
mask
is a bit mask of the interrupt sources to be cleared. Mask value is the logical OR of any of
the following
COMP_E_INTERRUPT_FLAG - Output interrupt flag
COMP_E_INTERRUPT_FLAG_INVERTED_POLARITY - Output interrupt flag inverted polarity
COMP_E_INTERRUPT_FLAG_READY - Ready interrupt flag
The Comparator interrupt source is cleared, so that it no longer asserts. The highest interrupt flag
is automatically cleared when an interrupt vector generator is used.
Returns
NONE
4.3.2.2
void COMP_E_disableInputBuffer ( uint32_t comparator, uint_fast16_t inputPort
)
Disables the input buffer of the selected input port to effectively allow for analog signals.
Thu Jan 21 2016 12:34:41 AM
45
Analog Comparator (COMP_E)
Parameters
comparator
is the instance of the Comparator module. Valid parameters vary from part to part, but
can include:
COMP_E0_BASE
COMP_E1_BASE
inputPort
is the port in which the input buffer will be disabled. Valid values are a logical OR of the
following:
COMP_E_INPUT0 [Default]
COMP_E_INPUT1
COMP_E_INPUT2
COMP_E_INPUT3
COMP_E_INPUT4
COMP_E_INPUT5
COMP_E_INPUT6
COMP_E_INPUT7
COMP_E_INPUT8
COMP_E_INPUT9
COMP_E_INPUT10
COMP_E_INPUT11
COMP_E_INPUT12
COMP_E_INPUT13
COMP_E_INPUT14
COMP_E_INPUT15
Modified bits are CEPDx of CECTL3 register.
This function sets the bit to disable the buffer for the specified input port to allow for analog signals
from any of the comparator input pins. This bit is automatically set when the input is initialized to
be used with the comparator module. This function should be used whenever an analog input is
connected to one of these pins to prevent parasitic voltage from causing unexpected results.
Thu Jan 21 2016 12:34:41 AM
46
Analog Comparator (COMP_E)
Returns
NONE
4.3.2.3
void COMP_E_disableInterrupt ( uint32_t comparator, uint_fast16_t mask )
Disables selected Comparator interrupt sources.
Parameters
comparator
is the instance of the Comparator module. Valid parameters vary from part to part, but
can include:
COMP_E0_BASE
COMP_E1_BASE
mask
is the bit mask of the interrupt sources to be disabled. Mask value is the logical OR of any
of the following
COMP_E_OUTPUT_INTERRUPT - Output interrupt
COMP_E_INVERTED_POLARITY_INTERRUPT - Output interrupt inverted polarity
COMP_E_READY_INTERRUPT - Ready interrupt
Disables the indicated Comparator interrupt sources. Only the sources that are enabled can be
reflected to the processor interrupt; disabled sources have no effect on the processor.
Returns
NONE
4.3.2.4
void COMP_E_disableModule ( uint32_t comparator )
Turns off the Comparator module.
Parameters
comparator
is the instance of the Comparator module. Valid parameters vary from part to part, but
can include:
COMP_E0_BASE
COMP_E1_BASE
This function clears the CEON bit disabling the operation of the Comparator module, saving from
excess power consumption.
Modified bits are CEON of CECTL1 register.
Thu Jan 21 2016 12:34:41 AM
47
Analog Comparator (COMP_E)
Returns
NONE
4.3.2.5
void COMP_E_enableInputBuffer ( uint32_t comparator, uint_fast16_t inputPort
)
Enables the input buffer of the selected input port to allow for digital signals.
Thu Jan 21 2016 12:34:41 AM
48
Analog Comparator (COMP_E)
Parameters
comparator
is the instance of the Comparator module. Valid parameters vary from part to part, but
can include:
COMP_E0_BASE
COMP_E1_BASE
inputPort
is the port in which the input buffer will be enabled. Valid values are a logical OR of the
following:
COMP_E_INPUT0 [Default]
COMP_E_INPUT1
COMP_E_INPUT2
COMP_E_INPUT3
COMP_E_INPUT4
COMP_E_INPUT5
COMP_E_INPUT6
COMP_E_INPUT7
COMP_E_INPUT8
COMP_E_INPUT9
COMP_E_INPUT10
COMP_E_INPUT11
COMP_E_INPUT12
COMP_E_INPUT13
COMP_E_INPUT14
COMP_E_INPUT15
Modified bits are CEPDx of CECTL3 register.
This function clears the bit to enable the buffer for the specified input port to allow for digital
signals from any of the comparator input pins. This should not be reset if there is an analog signal
connected to the specified input pin to prevent from unexpected results.
Thu Jan 21 2016 12:34:41 AM
49
Analog Comparator (COMP_E)
Returns
NONE
4.3.2.6
void COMP_E_enableInterrupt ( uint32_t comparator, uint_fast16_t mask )
Enables selected Comparator interrupt sources.
Parameters
comparator
is the instance of the Comparator module. Valid parameters vary from part to part, but
can include:
COMP_E0_BASE
COMP_E1_BASE
mask
is the bit mask of the interrupt sources to be enabled. Mask value is the logical OR of any
of the following
COMP_E_OUTPUT_INTERRUPT - Output interrupt
COMP_E_INVERTED_POLARITY_INTERRUPT - Output interrupt inverted polarity
COMP_E_READY_INTERRUPT - Ready interrupt
Enables the indicated Comparator interrupt sources. Only the sources that are enabled can be
reflected to the processor interrupt; disabled sources have no effect on the processor. The default
trigger for the non-inverted interrupt is a rising edge of the output, this can be changed with the
interruptSetEdgeDirection() function.
Returns
NONE
4.3.2.7
void COMP_E_enableModule ( uint32_t comparator )
Turns on the Comparator module.
Parameters
comparator
is the instance of the Comparator module. Valid parameters vary from part to part, but
can include:
COMP_E0_BASE
COMP_E1_BASE
This function sets the bit that enables the operation of the Comparator module.
Thu Jan 21 2016 12:34:41 AM
50
Analog Comparator (COMP_E)
Returns
NONE
4.3.2.8
uint_fast16_t COMP_E_getEnabledInterruptStatus ( uint32_t comparator )
Enables selected Comparator interrupt sources masked with the enabled interrupts. This function
is useful to call in ISRs to get a list of pending interrupts that are actually enabled and could have
caused the ISR.
Parameters
comparator
is the instance of the Comparator module. Valid parameters vary from part to part, but
can include:
COMP_E0_BASE
COMP_E1_BASE
Enables the indicated Comparator interrupt sources. Only the sources that are enabled can be
reflected to the processor interrupt; disabled sources have no effect on the processor. The default
trigger for the non-inverted interrupt is a rising edge of the output, this can be changed with the
COMP_E_setInterruptEdgeDirection() function.
Returns
NONE
References COMP_E_getInterruptStatus().
4.3.2.9
uint_fast16_t COMP_E_getInterruptStatus ( uint32_t comparator )
Gets the current Comparator interrupt status.
Parameters
comparator
is the instance of the Comparator module. Valid parameters vary from part to part, but
can include:
COMP_E0_BASE
COMP_E1_BASE
This returns the interrupt status for the Comparator module based on which flag is passed.
Returns
The current interrupt flag status for the corresponding mask.
Referenced by COMP_E_getEnabledInterruptStatus().
4.3.2.10 bool COMP_E_initModule ( uint32_t comparator, const COMP_E_Config ∗
config )
Initializes the Comparator Module.
Thu Jan 21 2016 12:34:41 AM
51
Analog Comparator (COMP_E)
Parameters
comparator
is the instance of the Comparator module. Valid parameters vary from part to part, but
can include:
COMP_E0_BASE
COMP_E1_BASE
config
Configuration structure for the Comparator module
Configuration options for COMP_E_Config structure.
Parameters
positiveTerminalInput
selects the input to the positive terminal. Valid values are
COMP_E_INPUT0 [Default]
COMP_E_INPUT1
COMP_E_INPUT2
COMP_E_INPUT3
COMP_E_INPUT4
COMP_E_INPUT5
COMP_E_INPUT6
COMP_E_INPUT7
COMP_E_INPUT8
COMP_E_INPUT9
COMP_E_INPUT10
COMP_E_INPUT11
COMP_E_INPUT12
COMP_E_INPUT13
COMP_E_INPUT14
COMP_E_INPUT15
COMP_E_VREF
Modified bits are CEIPSEL and CEIPEN of CECTL0 register, CERSEL of CECTL2
register, and CEPDx of CECTL3 register.
Thu Jan 21 2016 12:34:41 AM
52
Analog Comparator (COMP_E)
negativeTerminalInput
selects the input to the negative terminal.
Valid values are:
COMP_E_INPUT0 [Default]
COMP_E_INPUT1
COMP_E_INPUT2
COMP_E_INPUT3
COMP_E_INPUT4
COMP_E_INPUT5
COMP_E_INPUT6
COMP_E_INPUT7
COMP_E_INPUT8
COMP_E_INPUT9
COMP_E_INPUT10
COMP_E_INPUT11
COMP_E_INPUT12
COMP_E_INPUT13
COMP_E_INPUT14
COMP_E_INPUT15
COMP_E_VREF
Modified bits are CEIMSEL and CEIMEN of CECTL0 register, CERSEL of CECTL2
register, and CEPDx of CECTL3 register.
Thu Jan 21 2016 12:34:41 AM
53
Analog Comparator (COMP_E)
outputFilterEnableAndDelayLevel
controls the output filter delay state, which is either off or enabled with a specified delay
level.
Valid values are
COMP_E_FILTEROUTPUT_OFF [Default]
COMP_E_FILTEROUTPUT_DLYLVL1
COMP_E_FILTEROUTPUT_DLYLVL2
COMP_E_FILTEROUTPUT_DLYLVL3
COMP_E_FILTEROUTPUT_DLYLVL4
This parameter is device specific and delay levels should be found in the device’s
datasheet.
Modified bits are CEF and CEFDLY of CECTL1 register.
invertedOutputPolarity
controls if the output will be inverted or not. Valid values are
COMP_E_NORMALOUTPUTPOLARITY - indicates the output should be normal.
[Default]
COMP_E_INVERTEDOUTPUTPOLARITY - the output should be inverted.
Modified bits are CEOUTPOL of CECTL1 register.
powerMode
controls the power mode of the module
COMP_E_HIGH_SPEED_MODE [default]
COMP_E_NORMAL_MODE
COMP_E_ULTRA_LOW_POWER_MODE Upon successful initialization of the Comparator module, this function will have reset all necessary register bits and set
the given options in the registers. To actually use the comparator module,
the COMP_E_enableModule() function must be explicitly called before use. If
a Reference Voltage is set to a terminal, the Voltage should be set using the
COMP_E_setReferenceVoltage() function.
Returns
true or false of the initialization process.
4.3.2.11 uint8_t COMP_E_outputValue ( uint32_t comparator )
Returns the output value of the Comparator module.
Parameters
comparator
is the instance of the Comparator module. Valid parameters vary from part to part, but
can include:
COMP_E0_BASE
COMP_E1_BASE
Returns the output value of the Comparator module.
Thu Jan 21 2016 12:34:41 AM
54
Analog Comparator (COMP_E)
Returns
COMP_E_HIGH or COMP_E_LOW as the output value of the Comparator module.
4.3.2.12 void COMP_E_registerInterrupt ( uint32_t comparator, void(∗)(void) intHandler )
Registers an interrupt handler for the Comparator E interrupt.
Parameters
intHandler
comparator
is a pointer to the function to be called when the Comparator interrupt occurs.
is the instance of the Comparator module. Valid parameters vary from part to part, but
can include:
COMP_E0_BASE
COMP_E1_BASE
This function registers the handler to be called when a Comparator interrupt occurs. This function
enables the global interrupt in the interrupt controller; specific Comparator interrupts must be
enabled via COMP_E_enableInterrupt(). It is the interrupt handler’s responsibility to clear the
interrupt source via COMP_E_clearInterruptFlag().
Returns
None.
References Interrupt_enableInterrupt(), and Interrupt_registerInterrupt().
4.3.2.13 void COMP_E_setInterruptEdgeDirection ( uint32_t comparator, uint_fast8_t
edgeDirection )
Explicitly sets the edge direction that would trigger an interrupt.
Parameters
comparator
is the instance of the Comparator module. Valid parameters vary from part to part, but
can include:
COMP_E0_BASE
COMP_E1_BASE
edgeDirection
determines which direction the edge would have to go to generate an interrupt based on
the non-inverted interrupt flag. Valid values are
COMP_E_FALLINGEDGE - sets the bit to generate an interrupt when the output of
the comparator falls from HIGH to LOW if the normal interrupt bit is set(and LOW to
HIGH if the inverted interrupt enable bit is set). [Default]
COMP_E_RISINGEDGE - sets the bit to generate an interrupt when the output of
the comparator rises from LOW to HIGH if the normal interrupt bit is set(and HIGH
to LOW if the inverted interrupt enable bit is set).
Modified bits are CEIES of CECTL1 register.
This function will set which direction the output will have to go, whether rising or falling, to generate
an interrupt based on a non-inverted interrupt.
Thu Jan 21 2016 12:34:41 AM
55
Analog Comparator (COMP_E)
Returns
NONE
4.3.2.14 void COMP_E_setPowerMode ( uint32_t comparator, uint_fast16_t powerMode )
Sets the power mode
Parameters
comparator
is the instance of the Comparator module. Valid parameters vary from part to part, but
can include:
COMP_E0_BASE
COMP_E1_BASE
powerMode
decides the power mode Valid values are
COMP_E_HIGH_SPEED_MODE
COMP_E_NORMAL_MODE
COMP_E_ULTRA_LOW_POWER_MODE
Modified bits are CEPWRMD of CECTL1 register.
Returns
NONE
4.3.2.15 void COMP_E_setReferenceAccuracy ( uint32_t comparator, uint_fast16_t
referenceAccuracy )
Sets the reference accuracy
Parameters
comparator
is the instance of the Comparator module. Valid parameters vary from part to part, but
can include:
COMP_E0_BASE
COMP_E1_BASE
referenceAccuracy
is the reference accuracy setting of the comparator. Clocked is for low power/low accuracy.
Valid values are
COMP_E_ACCURACY_STATIC
COMP_E_ACCURACY_CLOCKED
Modified bits are CEREFACC of CECTL2 register.
Thu Jan 21 2016 12:34:41 AM
56
Analog Comparator (COMP_E)
The reference accuracy is set to the desired setting. Clocked is better for low power operations
but has a lower accuracy.
Returns
NONE
4.3.2.16 void COMP_E_setReferenceVoltage ( uint32_t comparator, uint_fast16_t supplyVoltageReferenceBase, uint_fast16_t lowerLimitSupplyVoltageFractionOf32,
uint_fast16_t upperLimitSupplyVoltageFractionOf32 )
Generates a Reference Voltage to the terminal selected during initialization.
Parameters
comparator
is the instance of the Comparator module. Valid parameters vary from part to part, but
can include:
COMP_E0_BASE
COMP_E1_BASE
supplyVoltageReferenceBase
decides the source and max amount of Voltage that can be used as a reference. Valid
values are
COMP_E_REFERENCE_AMPLIFIER_DISABLED
COMP_E_VREFBASE1_2V
COMP_E_VREFBASE2_0V
COMP_E_VREFBASE2_5V
upperLimitSupplyVoltageFractionOf32
lowerLimitSupplyVoltageFractionOf32
is the numerator of the equation to generate the reference voltage for the upper limit
reference voltage. Valid values are between 0 and 32.
is the numerator of the equation to generate the reference voltage for the lower limit reference voltage. Valid values are between 0 and 32.
Modified bits are CEREF0 of CECTL2 register.
Use this function to generate a voltage to serve as a reference to the terminal selected at
initialization. The voltage is determined by the equation: Vbase ∗ (Numerator / 32). If the upper
and lower limit voltage numerators are equal, then a static reference is defined, whereas they are
different then a hysteresis effect is generated.
Returns
NONE
4.3.2.17 void COMP_E_shortInputs ( uint32_t comparator )
Shorts the two input pins chosen during initialization.
Thu Jan 21 2016 12:34:41 AM
57
Analog Comparator (COMP_E)
Parameters
comparator
is the instance of the Comparator module. Valid parameters vary from part to part, but
can include:
COMP_E0_BASE
COMP_E1_BASE
This function sets the bit that shorts the devices attached to the input pins chosen from the
initialization of the comparator.
Modified bits are CESHORT of CECTL1 register.
Returns
NONE
4.3.2.18 void COMP_E_swapIO ( uint32_t comparator )
Toggles the bit that swaps which terminals the inputs go to, while also inverting the output of the
comparator.
Parameters
comparator
is the instance of the Comparator module. Valid parameters vary from part to part, but
can include:
\ bCOMP_E0
\ bCOMP_E1
This function toggles the bit that controls which input goes to which terminal. After initialization,
this bit is set to 0, after toggling it once the inputs are routed to the opposite terminal and the
output is inverted.
Modified bits are CEEX of CECTL1 register.
Returns
NONE
4.3.2.19 void COMP_E_toggleInterruptEdgeDirection ( uint32_t comparator )
Toggles the edge direction that would trigger an interrupt.
Parameters
comparator
is the instance of the Comparator module. Valid parameters vary from part to part, but
can include:
COMP_E0_BASE
COMP_E1_BASE
This function will toggle which direction the output will have to go, whether rising or falling, to
generate an interrupt based on a non-inverted interrupt. If the direction was rising, it is now falling,
if it was falling, it is now rising.
Thu Jan 21 2016 12:34:41 AM
58
Analog Comparator (COMP_E)
Modified bits are CEIES of CECTL1 register.
Returns
NONE
4.3.2.20 void COMP_E_unregisterInterrupt ( uint32_t comparator )
Unregisters the interrupt handler for the Comparator E interrupt
Parameters
comparator
is the instance of the Comparator module. Valid parameters vary from part to part, but
can include:
COMP_E0_BASE
COMP_E1_BASE
This function unregisters the handler to be called when Comparator E interrupt occurs. This
function also masks off the interrupt in the interrupt controller so that the interrupt handler no
longer is called.
See Also
Interrupt_registerInterrupt() for important information about registering interrupt handlers.
Returns
None.
References Interrupt_disableInterrupt(), and Interrupt_unregisterInterrupt().
4.3.2.21 void COMP_E_unshortInputs ( uint32_t comparator )
Disables the short of the two input pins chosen during initialization.
Parameters
comparator
is the instance of the Comparator module. Valid parameters vary from part to part, but
can include:
COMP_E0_BASE
COMP_E1_BASE
This function clears the bit that shorts the devices attached to the input pins chosen from the
initialization of the comparator.
Modified bits are CESHORT of CECTL1 register.
Returns
NONE
Thu Jan 21 2016 12:34:41 AM
59
Cyclic Redundancy Check 32 (CRC32)
5
Cyclic Redundancy Check 32 (CRC32)
Module Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60
Programming Example . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60
Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61
5.1
Module Operation
The Cyclic Redundancy Check 32 (CRC32) API provides a set of functions for using the
MSPWare CRC32 module. Functions are provided to initialize the CRC and create a CRC
signature to check the validity of data. This is mostly useful in the communication of data, or as a
startup procedure to as a more complex and accurate check of data.
The CRC32 module offers no interrupts and is used only to generate CRC signatures to verify
against pre-made CRC signatures (Checksums).
The CRC32 module provides the capability for both 32-bit and 16-bit calculations. As such, the
DriverLib API provides functionality for the user to provide variable bit-length data for either 16-bit
or 32-bit calculations.
5.2
Programming Example
The DriverLib package contains a variety of different code examples that demonstrate the usage
of the CRC32 module. These code examples are accessible under the examples/ folder of the
MSPWare release as well as through TI Resource Explorer if using Code Composer Studio.
These code examples provide a comprehensive list of use cases as well as practical applications
involving each module.
In the following very simple code example, an array of data is fed into the CRC32 module and the
32-bit calculation is retrieved:
Thu Jan 21 2016 12:34:41 AM
60
Cyclic Redundancy Check 32 (CRC32)
5.3
Definitions
Functions
uint32_t CRC32_getResult (uint_fast8_t crcType)
uint32_t CRC32_getResultReversed (uint_fast8_t crcType)
void CRC32_set16BitData (uint16_t dataIn, uint_fast8_t crcType)
void CRC32_set16BitDataReversed (uint16_t dataIn, uint_fast8_t crcType)
void CRC32_set32BitData (uint32_t dataIn)
void CRC32_set32BitDataReversed (uint32_t dataIn)
void CRC32_set8BitData (uint8_t dataIn, uint_fast8_t crcType)
void CRC32_set8BitDataReversed (uint8_t dataIn, uint_fast8_t crcType)
void CRC32_setSeed (uint32_t seed, uint_fast8_t crcType)
5.3.1
Detailed Description
The code for this module is contained in driverlib/crc32.c and
driverlib/legacy/MSP432xx/legacy_crc32.c, with driverlib/crc32.h and
driverlib/legacy/MSP432xx/legacy_crc32.h containing the API declarations for use by
applications.
Thu Jan 21 2016 12:34:41 AM
61
Cyclic Redundancy Check 32 (CRC32)
5.3.2
Function Documentation
5.3.2.1
uint32_t CRC32_getResult ( uint_fast8_t crcType )
Returns the value of CRC Signature Result.
Parameters
crcType
selects between CRC32 and CRC16 Valid values are CRC16_MODE and CRC32_MODE
This function returns the value of the signature result generated by the CRC. Bit 0 is treated as
LSB.
Returns
uint32_t Result
5.3.2.2
uint32_t CRC32_getResultReversed ( uint_fast8_t crcType )
Returns the bit-wise reversed format of the 32 bit Signature Result.
Parameters
crcType
selects between CRC32 and CRC16 Valid values are CRC16_MODE and CRC32_MODE
This function returns the bit-wise reversed format of the Signature Result. Bit 0 is treated as MSB.
Returns
uint32_t Result
5.3.2.3
void CRC32_set16BitData ( uint16_t dataIn, uint_fast8_t crcType )
Sets the 16 Bit data to add into the CRC module to generate a new signature.
Parameters
dataIn
crcType
is the data to be added, through the CRC module, to the signature. Modified bits are
CRC16DIW0 of CRC16DIW0 register. CRC32DIW0 of CRC32DIW0 register.
selects between CRC32 and CRC16 Valid values are CRC16_MODE and CRC32_MODE
This function sets the given data into the CRC module to generate the new signature from the
current signature and new data. Bit 0 is treated as LSB
Returns
NONE
5.3.2.4
void CRC32_set16BitDataReversed ( uint16_t dataIn, uint_fast8_t crcType )
Translates the data by reversing the bits in each 16 bit data and then sets this data to add into the
CRC module to generate a new signature.
Thu Jan 21 2016 12:34:41 AM
62
Cyclic Redundancy Check 32 (CRC32)
Parameters
dataIn
crcType
is the data to be added, through the CRC module, to the signature. Modified bits are
CRC16DIRBW0 of CRC16DIRBW0 register. CRC32DIRBW0 of CRC32DIRBW0 register.
selects between CRC32 and CRC16 Valid values are CRC16_MODE and CRC32_MODE
This function first reverses the bits in each byte of the data and then generates the new signature
from the current signature and new translated data. Bit 0 is treated as MSB.
Returns
NONE
5.3.2.5
void CRC32_set32BitData ( uint32_t dataIn )
Sets the 32 Bit data to add into the CRC module to generate a new signature. Available only for
CRC32_MODE and not for CRC16_MODE
Parameters
dataIn
is the data to be added, through the CRC module, to the signature. Modified bits are
CRC32DIL0 of CRC32DIL0 register.
This function sets the given data into the CRC module to generate the new signature from the
current signature and new data. Bit 0 is treated as LSB
Returns
NONE
5.3.2.6
void CRC32_set32BitDataReversed ( uint32_t dataIn )
Translates the data by reversing the bits in each 32 Bit Data and then sets this data to add into the
CRC module to generate a new signature. Available only for CRC32 mode and not for CRC16
mode
Parameters
dataIn
is the data to be added, through the CRC module, to the signature. Modified bits are
CRC32DIRBL0 of CRC32DIRBL0 register.
This function first reverses the bits in each byte of the data and then generates the new signature
from the current signature and new translated data. Bit 0 is treated as MSB.
Returns
NONE
5.3.2.7
void CRC32_set8BitData ( uint8_t dataIn, uint_fast8_t crcType )
Sets the 8 Bit data to add into the CRC module to generate a new signature.
Thu Jan 21 2016 12:34:41 AM
63
Cyclic Redundancy Check 32 (CRC32)
Parameters
dataIn
crcType
is the data to be added, through the CRC module, to the signature. Modified bits are
CRC16DIB0 of CRC16DIB0 register. CRC32DIB0 of CRC32DIB0 register.
selects between CRC32 and CRC16 Valid values are CRC16_MODE and CRC32_MODE
This function sets the given data into the CRC module to generate the new signature from the
current signature and new data. Bit 0 is treated as LSB.
Returns
NONE
5.3.2.8
void CRC32_set8BitDataReversed ( uint8_t dataIn, uint_fast8_t crcType )
Translates the data by reversing the bits in each 8 bit data and then sets this data to add into the
CRC module to generate a new signature.
Parameters
dataIn
crcType
is the data to be added, through the CRC module, to the signature. Modified bits are
CRC16DIRBB0 of CRC16DIRBB0 register. CRC32DIRBB0 of CRC32DIRBB0 register.
selects between CRC32 and CRC16 Valid values are CRC16_MODE and CRC32_MODE
This function first reverses the bits in each byte of the data and then generates the new signature
from the current signature and new translated data. Bit 0 is treated as MSB.
Returns
NONE
5.3.2.9
void CRC32_setSeed ( uint32_t seed, uint_fast8_t crcType )
Sets the seed for the CRC.
Parameters
seed
crcType
is the seed for the CRC to start generating a signature from. Modified bits are
CRC16INIRESL0 of CRC16INIRESL0 register. CRC32INIRESL0 of CRC32INIRESL0
register
selects between CRC32 and CRC16 Valid values are CRC16_MODE and CRC32_MODE
This function sets the seed for the CRC to begin generating a signature with the given seed and all
passed data. Using this function resets the CRC32 signature.
Returns
NONE
Thu Jan 21 2016 12:34:41 AM
64
Clock System (CS)
6
Clock System (CS)
Module Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65
Timeout Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65
Custom DCO Frequencies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65
Specifying External Crystal Frequencies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .65
Programming Example . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66
Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67
6.1
Module Operation
The clock system module for DriverLib gives users the ability to fully configure and control all
aspects of the MSP432 clock system. This includes initializing and maintaining the MCLK, ACLK,
HSMCLK, SMCLK, and BCLK clock systems. Additionally, APIs exist for configuring connected
crystal oscillators as well as configuring/manipulating the DCO and reference oscillator.
6.2
Timeout Parameters
For crystal configuration APIs (starting the LFXT and HFXT), a "timeout" API exists that will return
control of execution back to the user application if a specified duration passes. The variable that is
passed into these functions is a unit of time specified by how many "loop iterations" elapse before
unsuccessful stabilization of the respected crystal. The API will attempt to check to see if there
was a crystal fault, clear the crystal fault flag, and repeat the check until no fault exists. If the user
calls the API with a specified timeout, the loop will only check the given number of loop iterations
for a successfully stabilized crystal.
6.3
Custom DCO Frequency
For tuning the DCO frequency to a specific frequency, a convenient CS_setDCOFrequency
function is provided to users. This function accepts any uint32_t frequency and automatically
calculates the appropriate tuning parameters to get the DCO frequency as close as possible to the
provided frequency. Note that with this function, floating point math is involved so if efficiency is a
concern the user should enable the FPU using the FPU_enableModule function.
6.4
Specifying External Crystal Frequencies
MSP432 DriverLib has a variety of convenience functions for obtaining the specific frequency of a
clock source ( such as CS_getMCLK ). If a clock source is sourced from an external crystal, the
crystal frequency must be specified explicitly using the CS_setExternalClockSourceFrequency
function. This function must be used prior to the getters for the clock source if an external crystal
is used.
Thu Jan 21 2016 12:34:41 AM
65
Clock System (CS)
6.5
Programming Example
The DriverLib package contains a variety of different code examples that demonstrate the usage
of the CS module. These code examples are accessible under the examples/ folder of the
MSPWare release as well as through TI Resource Explorer if using Code Composer Studio.
These code examples provide a comprehensive list of use cases as well as practical applications
involving each module.
Below is a very brief code example showing how to start the external high frequency crystal and
source MCLK from this crystal. An LED is configured as an output in this example as well. For a
set of more detailed code examples, please refer to the code examples in the examples/ directory
of the MSPWare release:
/* Configuring pins for peripheral/crystal usage and LED for output */
MAP_GPIO_setAsPeripheralModuleFunctionOutputPin(GPIO_PORT_PJ,
GPIO_PIN3 | GPIO_PIN2, GPIO_PRIMARY_MODULE_FUNCTION);
MAP_GPIO_setAsOutputPin(GPIO_PORT_P1, GPIO_PIN0);
/* Just in case the user wants to use the getACLK, getMCLK,
* let’s set the clock frequency in the code.
*/
CS_setExternalClockSourceFrequency(32000, 48000000);
etc. functions,
/* Starting HFXT in non-bypass mode without a timeout. Before we start
* we have to change VCORE to 1 to support the 48MHz frequency */
MAP_PCM_setCoreVoltageLevel(PCM_VCORE1);
MAP_FlashCtl_setWaitState(FLASH_BANK0, 2);
MAP_FlashCtl_setWaitState(FLASH_BANK1, 2);
CS_startHFXT(false);
/* Initializing MCLK to HFXT (effectively 48MHz) */
MAP_CS_initClockSignal(CS_MCLK, CS_HFXTCLK_SELECT,
Thu Jan 21 2016 12:34:41 AM
CS_CLOCK_DIVIDER_1);
66
Clock System (CS)
6.6
Definitions
Functions
void CS_clearInterruptFlag (uint32_t flags)
void CS_disableClockRequest (uint32_t selectClock)
void CS_disableDCOExternalResistor (void)
void CS_disableFaultCounter (uint_fast8_t counterSelect)
void CS_disableInterrupt (uint32_t flags)
void CS_enableClockRequest (uint32_t selectClock)
void CS_enableDCOExternalResistor (void)
void CS_enableFaultCounter (uint_fast8_t counterSelect)
void CS_enableInterrupt (uint32_t flags)
uint32_t CS_getACLK (void)
uint32_t CS_getBCLK (void)
uint32_t CS_getDCOFrequency (void)
uint32_t CS_getEnabledInterruptStatus (void)
uint32_t CS_getHSMCLK (void)
uint32_t CS_getInterruptStatus (void)
uint32_t CS_getMCLK (void)
uint32_t CS_getSMCLK (void)
void CS_initClockSignal (uint32_t selectedClockSignal, uint32_t clockSource, uint32_t
clockSourceDivider)
void CS_registerInterrupt (void(∗intHandler)(void))
void CS_resetFaultCounter (uint_fast8_t counterSelect)
void CS_setDCOCenteredFrequency (uint32_t dcoFreq)
void CS_setDCOExternalResistorCalibration (uint_fast8_t uiCalData, uint_fast8_t freqRange)
void CS_setDCOFrequency (uint32_t dcoFrequency)
void CS_setExternalClockSourceFrequency (uint32_t lfxt_XT_CLK_frequency, uint32_t
hfxt_XT_CLK_frequency)
void CS_setReferenceOscillatorFrequency (uint8_t referenceFrequency)
void CS_startFaultCounter (uint_fast8_t counterSelect, uint_fast8_t countValue)
bool CS_startHFXT (bool bypassMode)
bool CS_startHFXTWithTimeout (bool bypassMode, uint32_t timeout)
bool CS_startLFXT (uint32_t xtDrive)
bool CS_startLFXTWithTimeout (uint32_t xtDrive, uint32_t timeout)
void CS_tuneDCOFrequency (int16_t tuneParameter)
void CS_unregisterInterrupt (void)
6.6.1
Detailed Description
The code for this module is contained in driverlib/cs.c, with driverlib/cs.h containing
the API declarations for use by applications.
Thu Jan 21 2016 12:34:41 AM
67
Clock System (CS)
6.6.2
Function Documentation
6.6.2.1
void CS_clearInterruptFlag ( uint32_t flags )
Clears clock system interrupt sources.
Parameters
flags
is a bit mask of the interrupt sources to be cleared. Must be a logical OR of:
CS_LFXT_FAULT,
CS_HFXT_FAULT,
CS_DCO_OPEN_FAULT,
CS_STARTCOUNT_LFXT_FAULT,
CS_STARTCOUNT_HFXT_FAULT,
The specified clock system interrupt sources are cleared, so that they no longer assert. This
function must be called in the interrupt handler to keep it from being called again immediately
upon exit.
Note
Because there is a write buffer in the Cortex-M processor, it may take several clock cycles
before the interrupt source is actually cleared. Therefore, it is recommended that the
interrupt source be cleared early in the interrupt handler (as opposed to the very last action)
to avoid returning from the interrupt handler before the interrupt source is actually cleared.
Failure to do so may result in the interrupt handler being immediately reentered (because the
interrupt controller still sees the interrupt source asserted).
The interrupt sources vary based on the part in use. Please consult the data sheet for the
part you are using to determine which interrupt sources are available.
Returns
None.
6.6.2.2
void CS_disableClockRequest ( uint32_t selectClock )
Disables conditional module requests
Parameters
selectClock
selects specific request disables. Valid values are are a logical OR of the following values:
CS_ACLK,
CS_HSMCLK,
CS_SMCLK,
CS_MCLK
Returns
NONE
Thu Jan 21 2016 12:34:41 AM
68
Clock System (CS)
6.6.2.3
void CS_disableDCOExternalResistor ( void )
Disables the external resistor for DCO operation
Returns
NONE
6.6.2.4
void CS_disableFaultCounter ( uint_fast8_t counterSelect )
Disables the fault counter for the CS module. This function can disable either the HFXT fault
counter or the LFXT fault counter.
Parameters
counterSelect
selects the fault counter to disable
CS_HFXT_FAULT_COUNTER
CS_LFXT_FAULT_COUNTER
Returns
NONE
6.6.2.5
void CS_disableInterrupt ( uint32_t flags )
Disables individual clock system interrupt sources.
Parameters
flags
is a bit mask of the interrupt sources to be disabled. Must be a logical OR of:
CS_LFXT_FAULT,
CS_HFXT_FAULT,
CS_DCOMIN_FAULT,
CS_DCOMAX_FAULT,
CS_DCO_OPEN_FAULT,
CS_STARTCOUNT_LFXT_FAULT,
CS_STARTCOUNT_HFXT_FAULT,
Note
The interrupt sources vary based on the part in use. Please consult the data sheet for the
part you are using to determine which interrupt sources are available.
Returns
None.
Thu Jan 21 2016 12:34:41 AM
69
Clock System (CS)
6.6.2.6
void CS_enableClockRequest ( uint32_t selectClock )
Enables conditional module requests
Thu Jan 21 2016 12:34:41 AM
70
Clock System (CS)
Parameters
selectClock
selects specific request enables. Valid values are are a logical OR of the following values:
CS_ACLK,
CS_HSMCLK,
CS_SMCLK,
CS_MCLK
Returns
NONE
6.6.2.7
void CS_enableDCOExternalResistor ( void )
Enables the external resistor for DCO operation
Returns
NONE
6.6.2.8
void CS_enableFaultCounter ( uint_fast8_t counterSelect )
Enables the fault counter for the CS module. This function can enable either the HFXT fault
counter or the LFXT fault counter.
Parameters
counterSelect
selects the fault counter to enable
CS_HFXT_FAULT_COUNTER
CS_LFXT_FAULT_COUNTER
Thu Jan 21 2016 12:34:41 AM
71
Clock System (CS)
Returns
NONE
6.6.2.9
void CS_enableInterrupt ( uint32_t flags )
Enables individual clock control interrupt sources.
Parameters
flags
is a bit mask of the interrupt sources to be enabled. Must be a logical OR of:
CS_LFXT_FAULT,
CS_HFXT_FAULT,
CS_DCOMIN_FAULT,
CS_DCOMAX_FAULT,
CS_DCO_OPEN_FAULT,
CS_STARTCOUNT_LFXT_FAULT,
CS_STARTCOUNT_HFXT_FAULT,
This function enables the indicated clock system interrupt sources. Only the sources that are
enabled can be reflected to the processor interrupt; disabled sources have no effect on the
processor.
Note
The interrupt sources vary based on the part in use. Please consult the data sheet for the
part you are using to determine which interrupt sources are available.
Returns
None.
6.6.2.10 uint32_t CS_getACLK ( void )
Get the current ACLK frequency.
If a oscillator fault is set, the frequency returned will be based on the fail safe mechanism of CS
module. The user of this API must ensure that CS_setExternalClockSourceFrequency() API was
invoked before in case LFXT is being used.
Returns
Current ACLK frequency in Hz
6.6.2.11 uint32_t CS_getBCLK ( void )
Get the current BCLK frequency.
If a oscillator fault is set, the frequency returned will be based on the fail safe mechanism of CS
module. The user of this API must ensure that CS_setExternalClockSourceFrequency API was
invoked before in case LFXT or HFXT is being used.
Thu Jan 21 2016 12:34:41 AM
72
Clock System (CS)
Returns
Current BCLK frequency in Hz
6.6.2.12 uint32_t CS_getDCOFrequency ( void )
Gets the current tuned DCO frequency. If no tuning has been done, this returns the nominal DCO
frequency of the current DCO range. Note that this function will grab any constant/calibration data
from the DDDS table without any user interaction needed.
Note
This function uses floating point math to calculate the DCO tuning parameter. If efficiency is
a concern, the user should use the FPU_enableModule function (if available) to enable the
floating point co-processor.
Returns
Current DCO frequency in Hz
References SysCtl_getTLVInfo().
6.6.2.13 uint32_t CS_getEnabledInterruptStatus ( void )
Gets the current interrupt status masked with the enabled interrupts. This function is useful to call
in ISRs to get a list of pending interrupts that are actually enabled and could have caused the ISR.
Returns
The current interrupt status, enumerated as a bit field of
CS_LFXT_FAULT,
CS_HFXT_FAULT,
CS_DCO_OPEN_FAULT,
CS_DCO_SHORT_FAULT,
CS_STARTCOUNT_LFXT_FAULT,
CS_STARTCOUNT_HFXT_FAULT,
Note
The interrupt sources vary based on the part in use. Please consult the data sheet for the
part you are using to determine which interrupt sources are available.
References CS_getInterruptStatus().
6.6.2.14 uint32_t CS_getHSMCLK ( void )
Get the current HSMCLK frequency.
If a oscillator fault is set, the frequency returned will be based on the fail safe mechanism of CS
module. The user of this API must ensure that CS_setExternalClockSourceFrequency API was
invoked before in case LFXT or HFXT is being used.
Returns
Current HSMCLK frequency in Hz
Thu Jan 21 2016 12:34:41 AM
73
Clock System (CS)
6.6.2.15 uint32_t CS_getInterruptStatus ( void )
Gets the current interrupt status.
Returns
The current interrupt status, enumerated as a bit field of:
CS_LFXT_FAULT,
CS_HFXT_FAULT,
CS_DCO_OPEN_FAULT,
CS_DCO_SHORT_FAULT,
CS_STARTCOUNT_LFXT_FAULT,
CS_STARTCOUNT_HFXT_FAULT,
Note
The interrupt sources vary based on the part in use. Please consult the data sheet for the
part you are using to determine which interrupt sources are available.
Referenced by CS_getEnabledInterruptStatus().
6.6.2.16 uint32_t CS_getMCLK ( void )
Get the current MCLK frequency.
If a oscillator fault is set, the frequency returned will be based on the fail safe mechanism of CS
module. The user of this API must ensure that CS_setExternalClockSourceFrequency API was
invoked before in case LFXT or HFXT is being used.
Returns
Current MCLK frequency in Hz
6.6.2.17 uint32_t CS_getSMCLK ( void )
Get the current SMCLK frequency.
If a oscillator fault is set, the frequency returned will be based on the fail safe mechanism of CS
module. The user of this API must ensure that CS_setExternalClockSourceFrequency API was
invoked before in case LFXT or HFXT is being used.
Returns
Current SMCLK frequency in Hz
6.6.2.18 void CS_initClockSignal ( uint32_t selectedClockSignal, uint32_t clockSource,
uint32_t clockSourceDivider )
This function initializes each of the clock signals. The user must ensure that this function is called
for each clock signal. If not, the default state is assumed for the particular clock signal. Refer to
DriverLib documentation for CS module or Device Family User’s Guide for details of default clock
signal states.
Thu Jan 21 2016 12:34:41 AM
74
Clock System (CS)
Note that this function is blocking and will wait on the appropriate bit to be set in the CSSTAT
READY register to be set before setting the clock source.
Also note that when HSMCLK and SMCLK share the same clock signal. If you change the clock
signal for HSMCLK, the clock signal for SMCLK will change also (and vice-versa).
HFXTCLK is not available for BCLK or ACLK.
Parameters
selectedClockSignal
Clock signal to initialize.
CS_ACLK,
CS_MCLK,
CS_HSMCLK
CS_SMCLK
CS_BCLK [clockSourceDivider is ignored for this parameter]
clockSource
Clock source for the selectedClockSignal signal.
CS_LFXTCLK_SELECT,
CS_HFXTCLK_SELECT,
CS_VLOCLK_SELECT, [Not available for BCLK]
CS_DCOCLK_SELECT, [Not available for ACLK, BCLK]
CS_REFOCLK_SELECT,
CS_MODOSC_SELECT [Not available for ACLK, BCLK]
clockSourceDivider
- selected the clock divider to calculate clock signal from clock source. This parameter is
ignored when setting BLCK. Valid values are:
CS_CLOCK_DIVIDER_1,
CS_CLOCK_DIVIDER_2,
CS_CLOCK_DIVIDER_4,
CS_CLOCK_DIVIDER_8,
CS_CLOCK_DIVIDER_16,
CS_CLOCK_DIVIDER_32,
CS_CLOCK_DIVIDER_64,
CS_CLOCK_DIVIDER_128
Returns
NONE
6.6.2.19 void CS_registerInterrupt ( void(∗)(void) intHandler )
Registers an interrupt handler for the clock system interrupt.
Thu Jan 21 2016 12:34:41 AM
75
Clock System (CS)
Parameters
intHandler
is a pointer to the function to be called when the clock system interrupt occurs.
This function registers the handler to be called when a clock system interrupt occurs. This function
enables the global interrupt in the interrupt controller; specific clock system interrupts must be
enabled via CS_enableInterrupt(). It is the interrupt handler’s responsibility to clear the interrupt
source via CS_clearInterruptFlag().
Clock System can generate interrupts when
See Also
Interrupt_registerInterrupt() for important information about registering interrupt handlers.
Returns
None.
References Interrupt_enableInterrupt(), and Interrupt_registerInterrupt().
6.6.2.20 void CS_resetFaultCounter ( uint_fast8_t counterSelect )
Resets the fault counter for the CS module. This function can reset either the HFXT fault counter
or the LFXT fault counter.
Parameters
counterSelect
selects the fault counter to reset
CS_HFXT_FAULT_COUNTER
CS_LFXT_FAULT_COUNTER
Returns
NONE
6.6.2.21 void CS_setDCOCenteredFrequency ( uint32_t dcoFreq )
Sets the centered frequency of DCO operation. Each frequency represents the centred frequency
of a particular frequency range. Further tuning can be achieved by using the
CS_tuneDCOFrequency function. Note that setting the nominal frequency will reset the tuning
parameters.
Parameters
dcoFreq
selects between the valid frequencies:
CS_DCO_FREQUENCY_1_5, [1MHz to 2MHz]
CS_DCO_FREQUENCY_3, [2MHz to 4MHz]
CS_DCO_FREQUENCY_6, [4MHz to 8MHz]
CS_DCO_FREQUENCY_12, [8MHz to 16MHz]
CS_DCO_FREQUENCY_24, [16MHz to 32MHz]
CS_DCO_FREQUENCY_48 [32MHz to 64MHz]
Thu Jan 21 2016 12:34:41 AM
76
Clock System (CS)
Returns
NONE
Referenced by CS_setDCOFrequency().
6.6.2.22 void CS_setDCOExternalResistorCalibration ( uint_fast8_t uiCalData,
uint_fast8_t freqRange )
Sets the calibration value for the DCO when using the external resistor mode. This value is used
for tuning the DCO to custom frequencies. By default, the value in the CS module is populated by
the calibration data of the suggested external resistor (see device datasheet).
Parameters
calData
freqRange
is the calibration data constant for the external resistor.
is the range of the DCO to set the external calibration for. Frequencies above 32MHZ
have a different calibration value than frequencies below 32MHZ.
Returns
None
6.6.2.23 void CS_setDCOFrequency ( uint32_t dcoFrequency )
Automatically sets/tunes the DCO to the given frequency. Any valid value up to max frequency in
the spec can be given to this function and the API will do its best to determine the correct tuning
parameter.
Note
The frequency ranges that can be custom tuned on early release MSP432 devices is limited.
For further details on supported tunable frequencies, please refer to the device errata sheet
or data sheet.
Parameters
dcoFrequency
Frequency in Hz that the user wants to set the DCO to.
Note
This function uses floating point math to calculate the DCO tuning parameter. If efficiency is
a concern, the user should use the FPU_enableModule function (if available) to enable the
floating point co-processor.
Returns
None
Automatically sets/tunes the DCO to the given frequency. Any valid value up to (and including)
64Mhz can be given to this function and the API will do its best to determine the correct tuning
parameter.
Thu Jan 21 2016 12:34:41 AM
77
Clock System (CS)
Note
This function is not currently available on pre-release MSP432 devices. On early release
versions of MSP432, the DCO calibration information has not been populated making the
DCO only able to operate at the pre-calibrated centered frequencies accessible by the
CS_setDCOCenteredFrequency function. While this function will be added on the final
devices being released, for early silicon please default to the pre-calibrated DCO center
frequencies.
Parameters
dcoFrequency
Frequency in Hz (1500000 - 64000000) that the user wants to set the DCO to.
Note
This function uses floating point math to calculate the DCO tuning parameter. If efficiency is
a concern, the user should use the FPU_enableModule function (if available) to enable the
floating point co-processor.
Returns
None
References CS_setDCOCenteredFrequency(), CS_tuneDCOFrequency(), and
SysCtl_getTLVInfo().
6.6.2.24 void CS_setExternalClockSourceFrequency ( uint32_t lfxt_XT_CLK_frequency,
uint32_t hfxt_XT_CLK_frequency )
This function sets the external clock sources LFXT and HFXT crystal oscillator frequency values.
This function must be called if an external crystal LFXT or HFXT is used and the user intends to
call CS_getSMCLK, CS_getMCLK, CS_getBCLK, CS_getHSMCLK, CS_getACLK and any of the
HFXT oscillator control functions
Parameters
is the LFXT crystal frequencies in Hz
lfxt_XT_CLK_frequency
is the HFXT crystal frequencies in Hz
hfxt_XT_CLK_frequency
Returns
None
6.6.2.25 void CS_setReferenceOscillatorFrequency ( uint8_t referenceFrequency )
Selects between the frequency of the internal REFO clock source
Parameters
Thu Jan 21 2016 12:34:41 AM
78
Clock System (CS)
referenceFrequency
selects between the valid frequencies:
CS_REFO_32KHZ,
CS_REFO_128KHZ,
Returns
NONE
6.6.2.26 void CS_startFaultCounter ( uint_fast8_t counterSelect, uint_fast8_t countValue
)
Sets the count for the start value of the fault counter. This function can be used to set either the
HFXT count or the LFXT count.
Parameters
counterSelect
selects the fault counter to reset
CS_HFXT_FAULT_COUNTER
CS_LFXT_FAULT_COUNTER
countValue
selects the cycles to set the fault counter to
CS_FAULT_COUNTER_4096_CYCLES
CS_FAULT_COUNTER_8192_CYCLES
CS_FAULT_COUNTER_16384_CYCLES
CS_FAULT_COUNTER_32768_CYCLES
Returns
NONE
6.6.2.27 bool CS_startHFXT ( bool bypassMode )
Initializes the HFXT crystal oscillator, which supports crystal frequencies between 0 MHz and 48
MHz, depending on the selected drive strength. Loops until all oscillator fault flags are cleared,
with no timeout. See the device-specific data sheet for appropriate drive settings. NOTE: User
must call CS_setExternalClockSourceFrequency to set frequency of external clocks before calling
this function.
Parameters
bypassMode
When this variable is set, the oscillator will start in bypass mode and the signal can be
generated by a digital square wave.
Returns
true if started correctly, false otherwise
References CS_startHFXTWithTimeout().
Thu Jan 21 2016 12:34:41 AM
79
Clock System (CS)
6.6.2.28 bool CS_startHFXTWithTimeout ( bool bypassMode, uint32_t timeout )
Initializes the HFXT crystal oscillator, which supports crystal frequencies between 0 MHz and 48
MHz, depending on the selected drive strength. Loops until all oscillator fault flags are cleared,
with no timeout. See the device-specific data sheet for appropriate drive settings. NOTE: User
must call CS_setExternalClockSourceFrequency to set frequency of external clocks before calling
this function. This function has a timeout associated with stabilizing the oscillator.
Parameters
bypassMode
timeout
When this variable is set, the oscillator will start in bypass mode and the signal can be
generated by a digital square wave.
is the count value that gets decremented every time the loop that clears oscillator fault
flags gets executed.
Returns
true if started correctly, false otherwise
References SysCtl_disableNMISource(), SysCtl_enableNMISource(), and
SysCtl_getNMISourceStatus().
Referenced by CS_startHFXT().
6.6.2.29 bool CS_startLFXT ( uint32_t xtDrive )
Initializes the LFXT crystal oscillator, which supports crystal frequencies up to 50kHz, depending
on the selected drive strength. Loops until all oscillator fault flags are cleared, with no timeout.
See the device-specific data sheet for appropriate drive settings. NOTE: User must call
CS_setExternalClockSourceFrequency to set frequency of external clocks before calling this
function.
Parameters
xtDrive
is the target drive strength for the LFXT crystal oscillator. Valid values are:
CS_LFXT_DRIVE0,
CS_LFXT_DRIVE1,
CS_LFXT_DRIVE2,
CS_LFXT_DRIVE3, [Default Value]
CS_LFXT_BYPASS
Note
When CS_LFXT_BYPASS is passed as a parameter the oscillator will start in bypass mode
and the signal can be generated by a digital square wave.
Returns
true if started correctly, false otherwise
References CS_startLFXTWithTimeout().
Thu Jan 21 2016 12:34:41 AM
80
Clock System (CS)
6.6.2.30 bool CS_startLFXTWithTimeout ( uint32_t xtDrive, uint32_t timeout )
Initializes the LFXT crystal oscillator, which supports crystal frequencies up to 50kHz, depending
on the selected drive strength. Loops until all oscillator fault flags are cleared. See the
device-specific data sheet for appropriate drive settings. NOTE: User must call
CS_setExternalClockSourceFrequency to set frequency of external clocks before calling this
function. This function has a timeout associated with stabilizing the oscillator.
Parameters
xtDrive
is the target drive strength for the LFXT crystal oscillator. Valid values are:
CS_LFXT_DRIVE0,
CS_LFXT_DRIVE1,
CS_LFXT_DRIVE2,
CS_LFXT_DRIVE3, [Default Value]
CS_LFXT_BYPASS
Note
When CS_LFXT_BYPASS is passed as a parameter the oscillator will start in bypass mode
and the signal can be generated by a digital square wave.
Parameters
timeout
is the count value that gets decremented every time the loop that clears oscillator fault
flags gets executed.
Returns
true if started correctly, false otherwise
References SysCtl_disableNMISource(), SysCtl_enableNMISource(), and
SysCtl_getNMISourceStatus().
Referenced by CS_startLFXT().
6.6.2.31 void CS_tuneDCOFrequency ( int16_t tuneParameter )
Tunes the DCO to a specific frequency. Tuning of the DCO is based off of the following equation in
the user’s guide:
See the user’s guide for more detailed information about DCO tuning.
Note
This function is not currently available on pre-release MSP432 devices. On early release
versions of MSP432, the DCO calibration information has not been populated making the
DCO only able to operate at the pre-calibrated centered frequencies accessible by the
CS_setDCOCenteredFrequency function. While this function will be added on the final
devices being released, for early silicon please default to the pre-calibrated DCO center
frequencies.
Thu Jan 21 2016 12:34:41 AM
81
Clock System (CS)
Parameters
tuneParameter
Tuning parameter in 2’s Compliment representation. Can be negative or positive.
Returns
NONE
Referenced by CS_setDCOFrequency().
6.6.2.32 void CS_unregisterInterrupt ( void )
Unregisters the interrupt handler for the clock system.
This function unregisters the handler to be called when a clock system interrupt occurs. This
function also masks off the interrupt in the interrupt controller so that the interrupt handler no
longer is called.
See Also
Interrupt_registerInterrupt() for important information about registering interrupt handlers.
Returns
None.
References Interrupt_disableInterrupt(), and Interrupt_unregisterInterrupt().
Thu Jan 21 2016 12:34:41 AM
82
Direct Memory Access Controller (DMA)
7
Direct Memory Access Controller (DMA)
Module Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83
Conversion Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85
Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86
7.1
Module Operation
The Micro Direct Memory Access (DMA) API provides functions to configure the MSP432 uDMA
controller. The DMA controller is designed to work with the ARM Cortex-M processor and provides
an efficient and low-overhead means of transferring blocks of data in the system.
The DMA controller has the following features:
dedicated channels for supported peripherals
one channel each for receive and transmit for devices with receive and transmit paths
dedicated channel for software initiated data transfers
channels can be independently configured and operated
an arbitration scheme that is configurable per channel
two levels of priority
subordinate to Cortex-M processor bus usage
data sizes of 8, 16, or 32 bits
address increment of byte, half-word, word, or none
maskable device requests
optional software initiated transfers on any channel
interrupt on transfer completion
The uDMA controller supports several different transfer modes, allowing for complex transfer
schemes. The following transfer modes are provided:
Basic mode performs a simple transfer when a request is asserted by a device. This mode is
appropriate to use with peripherals where the peripheral asserts the request signal whenever
data should be transferred. The transfer pauses if the request is de-asserted, even if the
transfer is not complete.
Auto-request mode performs a simple transfer that is started by a request, but always
completes the entire transfer, even if the request is de-asserted. This mode is appropriate to
use with software-initiated transfers.
Ping-Pong mode is used to transfer data to or from two buffers, switching from one buffer to
the other as each buffer fills. This mode is appropriate to use with peripherals as a way to
ensure a continuous flow of data to or from the peripheral. However, it is more complex to set
up and requires code to manage the ping-pong buffers in the interrupt handler.
Memory scatter-gather mode is a complex mode that provides a way to set up a list of
transfer “tasks” for the uDMA controller. Blocks of data can be transferred to and from
arbitrary locations in memory.
Peripheral scatter-gather mode is similar to memory scatter-gather mode except that it is
controlled by a peripheral request.
Thu Jan 21 2016 12:34:41 AM
83
Direct Memory Access Controller (DMA)
Detailed explanation of the various transfer modes is beyond the scope of this document. Please
refer to the device data sheet for more information on the operation of the uDMA controller.
Thu Jan 21 2016 12:34:41 AM
84
Direct Memory Access Controller (DMA)
7.2
Programming Example
The DriverLib package contains a variety of different code examples that demonstrate the usage
of the DMA module. These code examples are accessible under the examples/ folder of the
MSPWare release as well as through TI Resource Explorer if using Code Composer Studio.
These code examples provide a comprehensive list of use cases as well as practical applications
involving each module.
Below is a very brief example of how to configure the DMA controller to transfer from a data array
(data_array) to the EUSCI I2C module to be sent over the I2C line. This is useful in the sense that
the EUSCI module does not constantly have to wake up the CPU in order to load the next byte into
the buffer.
/* Configuring DMA module */
MAP_DMA_enableModule();
MAP_DMA_setControlBase(controlTable);
/* Assigning Channel 2 to EUSCIB1TX0, and Channel 5 to EUSCIB2RX0
* enabling channels 2 and 5*/
MAP_DMA_assignChannel(DMA_CH2_EUSCIB1TX0);
MAP_DMA_assignChannel(DMA_CH5_EUSCIB2RX0);
and
/* Disabling channel attributes */
MAP_DMA_disableChannelAttribute(DMA_CH2_EUSCIB1TX0,
UDMA_ATTR_ALTSELECT | UDMA_ATTR_USEBURST |
UDMA_ATTR_HIGH_PRIORITY |
UDMA_ATTR_REQMASK);
MAP_DMA_disableChannelAttribute(DMA_CH5_EUSCIB2RX0,
UDMA_ATTR_ALTSELECT | UDMA_ATTR_USEBURST |
UDMA_ATTR_HIGH_PRIORITY |
UDMA_ATTR_REQMASK);
/* Setting Control Indexes */
MAP_DMA_setChannelControl(UDMA_PRI_SELECT | DMA_CH2_EUSCIB1TX0,
UDMA_SIZE_8 | UDMA_SRC_INC_8 | UDMA_DST_INC_NONE | UDMA_ARB_1);
MAP_DMA_setChannelControl(UDMA_PRI_SELECT | DMA_CH5_EUSCIB2RX0,
UDMA_SIZE_8 | UDMA_SRC_INC_NONE | UDMA_DST_INC_8 | UDMA_ARB_1);
MAP_DMA_setChannelTransfer(UDMA_PRI_SELECT | DMA_CH2_EUSCIB1TX0,
UDMA_MODE_BASIC, data_array,
(void*) MAP_I2C_getTransmitBufferAddressForDMA(EUSCI_B1_BASE), 1024);
MAP_DMA_setChannelTransfer(UDMA_PRI_SELECT | DMA_CH5_EUSCIB2RX0,
UDMA_MODE_BASIC,
(void*)MAP_I2C_getReceiveBufferAddressForDMA(EUSCI_B2_BASE), recBuffer,
1024);
/* Assigning/Enabling Interrupts */
MAP_DMA_assignInterrupt(DMA_INT1, 2);
MAP_Interrupt_enableInterrupt(INT_DMA_INT1);
/* Now that the DMA is primed and setup, enabling the channels. The EUSCI
* hardware should take over and transfer/receive all bytes */
MAP_DMA_enableChannel(2);
MAP_DMA_enableChannel(5);
/* Sending the start condition */
MAP_I2C_masterSendStart(EUSCI_B1_BASE);
while(!MAP_I2C_masterIsStartSent(EUSCI_B1_BASE));
Thu Jan 21 2016 12:34:41 AM
85
Direct Memory Access Controller (DMA)
7.3
Definitions
Macros
#define DMA_TaskStructEntry(transferCount, itemSize, srcIncrement, srcAddr, dstIncrement,
dstAddr, arbSize, mode)
Functions
void DMA_assignChannel (uint32_t mapping)
void DMA_assignInterrupt (uint32_t interruptNumber, uint32_t channel)
void DMA_clearErrorStatus (void)
void DMA_clearInterruptFlag (uint32_t intChannel)
void DMA_disableChannel (uint32_t channelNum)
void DMA_disableChannelAttribute (uint32_t channelNum, uint32_t attr)
void DMA_disableInterrupt (uint32_t interruptNumber)
void DMA_disableModule (void)
void DMA_enableChannel (uint32_t channelNum)
void DMA_enableChannelAttribute (uint32_t channelNum, uint32_t attr)
void DMA_enableInterrupt (uint32_t interruptNumber)
void DMA_enableModule (void)
uint32_t DMA_getChannelAttribute (uint32_t channelNum)
uint32_t DMA_getChannelMode (uint32_t channelStructIndex)
uint32_t DMA_getChannelSize (uint32_t channelStructIndex)
void ∗ DMA_getControlAlternateBase (void)
void ∗ DMA_getControlBase (void)
uint32_t DMA_getErrorStatus (void)
uint32_t DMA_getInterruptStatus (void)
bool DMA_isChannelEnabled (uint32_t channelNum)
void DMA_registerInterrupt (uint32_t intChannel, void(∗intHandler)(void))
void DMA_requestChannel (uint32_t channelNum)
void DMA_requestSoftwareTransfer (uint32_t channel)
void DMA_setChannelControl (uint32_t channelStructIndex, uint32_t control)
void DMA_setChannelScatterGather (uint32_t channelNum, uint32_t taskCount, void
∗taskList, uint32_t isPeriphSG)
void DMA_setChannelTransfer (uint32_t channelStructIndex, uint32_t mode, void ∗srcAddr,
void ∗dstAddr, uint32_t transferSize)
void DMA_setControlBase (void ∗controlTable)
void DMA_unregisterInterrupt (uint32_t intChannel)
7.3.1
Detailed Description
The code for this module is contained in driverlib/dma.c, with driverlib/dma.h containing
the API declarations for use by applications.
Thu Jan 21 2016 12:34:41 AM
86
Direct Memory Access Controller (DMA)
7.3.2
Macro Definition Documentation
7.3.2.1
#define DMA_TaskStructEntry( transferCount, itemSize, srcIncrement,
srcAddr, dstIncrement, dstAddr, arbSize, mode )
A helper macro for building scatter-gather task table entries.
This macro is intended to be used to help populate a table of DMA tasks for a scatter-gather
transfer. This macro will calculate the values for the fields of a task structure entry based on the
input parameters.
There are specific requirements for the values of each parameter. No checking is done so it is up
to the caller to ensure that correct values are used for the parameters.
The transferCount parameter is the number of items that will be transferred by this task. It must
be in the range 1-1024.
The itemSize parameter is the bit size of the transfer data. It must be one of UDMA_SIZE_8,
UDMA_SIZE_16, or UDMA_SIZE_32.
The srcIncrement parameter is the increment size for the source data. It must be one of
UDMA_SRC_INC_8, UDMA_SRC_INC_16, UDMA_SRC_INC_32, or UDMA_SRC_INC_NONE.
The srcAddr parameter is a void pointer to the beginning of the source data.
The dstIncrement parameter is the increment size for the destination data. It must be one of
UDMA_DST_INC_8, UDMA_DST_INC_16, UDMA_DST_INC_32, or UDMA_DST_INC_NONE.
The dstAddr parameter is a void pointer to the beginning of the location where the data will be
transferred.
The arbSize parameter is the arbitration size for the transfer, and must be one of UDMA_ARB_1,
UDMA_ARB_2, UDMA_ARB_4, and so on up to UDMA_ARB_1024. This is used to select the
arbitration size in powers of 2, from 1 to 1024.
The mode parameter is the mode to use for this transfer task. It must be one of
UDMA_MODE_BASIC, UDMA_MODE_AUTO, UDMA_MODE_MEM_SCATTER_GATHER, or
UDMA_MODE_PER_SCATTER_GATHER. Note that normally all tasks will be one of the
scatter-gather modes while the last task is a task list will be AUTO or BASIC.
This macro is intended to be used to initialize individual entries of a structure of
DMA_ControlTable type, like this:
*
*
*
*
*
*
*
*
*
DMA_ControlTable MyTaskList[] =
{
DMA_TaskStructEntry(Task1Count, UDMA_SIZE_8,
UDMA_SRC_INC_8, MySourceBuf,
UDMA_DST_INC_8, MyDestBuf,
UDMA_ARB_8, UDMA_MODE_MEM_SCATTER_GATHER),
DMA_TaskStructEntry(Task2Count, ... ),
}
Parameters
transferCount
Thu Jan 21 2016 12:34:41 AM
is the count of items to transfer for this task.
87
Direct Memory Access Controller (DMA)
itemSize
srcIncrement
srcAddr
dstIncrement
dstAddr
arbSize
mode
is the bit size of the items to transfer for this task.
is the bit size increment for source data.
is the starting address of the data to transfer.
is the bit size increment for destination data.
is the starting address of the destination data.
is the arbitration size to use for the transfer task.
is the transfer mode for this task.
Returns
Nothing; this is not a function.
7.3.3
Function Documentation
7.3.3.1
void DMA_assignChannel ( uint32_t mapping )
Assigns a peripheral mapping for a DMA channel.
Parameters
mapping
is a macro specifying the peripheral assignment for a channel.
This function assigns a peripheral mapping to a DMA channel. It is used to select which peripheral
is used for a DMA channel. The parameter mapping should be one of the macros named
UDMA_CHn_tttt from the header file dma.h. For example, to assign DMA channel 0 to the eUSCI
AO RX channel, the parameter should be the macro UDMA_CH1_EUSCIA0RX.
Please consult the data sheet for a table showing all the possible peripheral assignments for the
DMA channels for a particular device.
Returns
None.
7.3.3.2
void DMA_assignInterrupt ( uint32_t interruptNumber, uint32_t channel )
Assigns a specific DMA channel to the corresponding interrupt handler. For MSP432 devices,
there are three configurable interrupts, and one master interrupt. This function will assign a
specific DMA channel to the provided configurable DMA interrupt.
Note that once a channel is assigned to a configurable interrupt, it will be masked in hardware
from the master DMA interrupt (interruptNumber zero). This function can also be used in
conjunction with the DMAIntTrigger function to provide the feature to software trigger specific
channel interrupts.
Parameters
interruptNumber
is the configurable interrupt to assign the given channel. Valid values are:
DMA_INT1 the first configurable DMA interrupt handler
DMA_INT2 the second configurable DMA interrupt handler
DMA_INT3 the third configurable DMA interrupt handler
channel
Thu Jan 21 2016 12:34:41 AM
is the channel to assign the interrupt
88
Direct Memory Access Controller (DMA)
Returns
None.
References DMA_enableInterrupt().
7.3.3.3
void DMA_clearErrorStatus ( void )
Clears the DMA error interrupt.
This function clears a pending DMA error interrupt. This function should be called from within the
DMA error interrupt handler to clear the interrupt.
Returns
None.
7.3.3.4
void DMA_clearInterruptFlag ( uint32_t intChannel )
Clears the DMA controller channel interrupt mask for interrupt zero.
Parameters
channel
is the channel interrupt to clear.
This function is used to clear the interrupt status of the DMA controller. Note that only interrupts
that weren’t assigned to DMA interrupts one through three using the DMA_assignInterrupt function
will be affected by thisfunctions. For other DMA interrupts, only one channel can be associated
and therefore clearing in unnecessary.
Returns
None
7.3.3.5
void DMA_disableChannel ( uint32_t channelNum )
Disables a DMA channel for operation.
Parameters
channelNum
is the channel number to disable.
This function disables a specific DMA channel. Once disabled, a channel cannot respond to DMA
transfer requests until re-enabled via DMA_enableChannel().
Returns
None.
7.3.3.6
void DMA_disableChannelAttribute ( uint32_t channelNum, uint32_t attr )
Disables attributes of a DMA channel.
Thu Jan 21 2016 12:34:41 AM
89
Direct Memory Access Controller (DMA)
Parameters
channelNum
attr
is the channel to configure.
is a combination of attributes for the channel.
This function is used to disable attributes of a DMA channel.
The attr parameter is the logical OR of any of the following:
UDMA_ATTR_USEBURST is used to restrict transfers to use only burst mode.
UDMA_ATTR_ALTSELECT is used to select the alternate control structure for this channel.
UDMA_ATTR_HIGH_PRIORITY is used to set this channel to high priority.
UDMA_ATTR_REQMASK is used to mask the hardware request signal from the peripheral
for this channel.
Returns
None.
7.3.3.7
void DMA_disableInterrupt ( uint32_t interruptNumber )
Disables the specified interrupt for the DMA controller.
Parameters
interruptNumber
identifies which DMA interrupt is to be disabled. This interrupt should be one of the following:
DMA_INT0 the master DMA interrupt handler
DMA_INT1 the first configurable DMA interrupt handler
DMA_INT2 the second configurable DMA interrupt handler
DMA_INT3 the third configurable DMA interrupt handler
DMA_INTERR the third configurable DMA interrupt handler
Note for interrupts that are associated with a specific DMA channel (DMA_INT1 DMA_INT3), this function will also enable that specific channel for interrupts.
Returns
None.
7.3.3.8
void DMA_disableModule ( void )
Disables the DMA controller for use.
This function disables the DMA controller. Once disabled, the DMA controller cannot operate until
re-enabled with DMA_enableModule().
Returns
None.
Thu Jan 21 2016 12:34:41 AM
90
Direct Memory Access Controller (DMA)
7.3.3.9
void DMA_enableChannel ( uint32_t channelNum )
Enables a DMA channel for operation.
Thu Jan 21 2016 12:34:41 AM
91
Direct Memory Access Controller (DMA)
Parameters
channelNum
is the channel number to enable.
When a DMA transfer is completed, the channel is automatically disabled by the DMA controller.
Therefore, this function should be called prior to starting up any new transfer.
Returns
None.
7.3.3.10 void DMA_enableChannelAttribute ( uint32_t channelNum, uint32_t attr )
Enables attributes of a DMA channel.
Parameters
channelNum
attr
is the channel to configure.
is a combination of attributes for the channel.
This function is used to enable attributes of a DMA channel.
The attr parameter is the logical OR of any of the following:
UDMA_ATTR_USEBURST is used to restrict transfers to use only burst mode.
UDMA_ATTR_ALTSELECT is used to select the alternate control structure for this channel
(it is very unlikely that this flag should be used).
UDMA_ATTR_HIGH_PRIORITY is used to set this channel to high priority.
UDMA_ATTR_REQMASK is used to mask the hardware request signal from the peripheral
for this channel.
Returns
None.
7.3.3.11 void DMA_enableInterrupt ( uint32_t interruptNumber )
Enables the specified interrupt for the DMA controller. Note for interrupts one through three,
specific channels have to be mapped to the interrupt using the DMA_assignInterrupt function.
Parameters
interruptNumber
identifies which DMA interrupt is to be enabled. This interrupt should be one of the following:
DMA_INT0 the master DMA interrupt handler
DMA_INT1 the first configurable DMA interrupt handler
DMA_INT2 the second configurable DMA interrupt handler
DMA_INT3 the third configurable DMA interrupt handler
DMA_INTERR the third configurable DMA interrupt handler
Returns
None.
Referenced by DMA_assignInterrupt().
Thu Jan 21 2016 12:34:41 AM
92
Direct Memory Access Controller (DMA)
7.3.3.12 void DMA_enableModule ( void )
Enables the DMA controller for use.
This function enables the DMA controller. The DMA controller must be enabled before it can be
configured and used.
Returns
None.
7.3.3.13 uint32_t DMA_getChannelAttribute ( uint32_t channelNum )
Gets the enabled attributes of a DMA channel.
Parameters
channelNum
is the channel to configure.
This function returns a combination of flags representing the attributes of the DMA channel.
Returns
Returns the logical OR of the attributes of the DMA channel, which can be any of the
following:
UDMA_ATTR_USEBURST is used to restrict transfers to use only burst mode.
UDMA_ATTR_ALTSELECT is used to select the alternate control structure for this
channel.
UDMA_ATTR_HIGH_PRIORITY is used to set this channel to high priority.
UDMA_ATTR_REQMASK is used to mask the hardware request signal from the
peripheral for this channel.
7.3.3.14 uint32_t DMA_getChannelMode ( uint32_t channelStructIndex )
Gets the transfer mode for a DMA channel control structure.
Parameters
channelStructIndex
is the logical OR of the DMA channel number with either UDMA_PRI_SELECT or
UDMA_ALT_SELECT.
This function is used to get the transfer mode for the DMA channel and to query the status of a
transfer on a channel. When the transfer is complete the mode is UDMA_MODE_STOP.
Returns
Returns the transfer mode of the specified channel and control structure, which is one of the
following values: UDMA_MODE_STOP, UDMA_MODE_BASIC, UDMA_MODE_AUTO,
UDMA_MODE_PINGPONG, UDMA_MODE_MEM_SCATTER_GATHER, or
UDMA_MODE_PER_SCATTER_GATHER.
7.3.3.15 uint32_t DMA_getChannelSize ( uint32_t channelStructIndex )
Gets the current transfer size for a DMA channel control structure.
Thu Jan 21 2016 12:34:41 AM
93
Direct Memory Access Controller (DMA)
Parameters
channelStructIndex
is the logical OR of the DMA channel number with either UDMA_PRI_SELECT or
UDMA_ALT_SELECT.
This function is used to get the DMA transfer size for a channel. The transfer size is the number of
items to transfer, where the size of an item might be 8, 16, or 32 bits. If a partial transfer has
already occurred, then the number of remaining items is returned. If the transfer is complete, then
0 is returned.
Returns
Returns the number of items remaining to transfer.
7.3.3.16 void∗ DMA_getControlAlternateBase ( void )
Gets the base address for the channel control table alternate structures.
This function gets the base address of the second half of the channel control table that holds the
alternate control structures for each channel.
Returns
Returns a pointer to the base address of the second half of the channel control table.
7.3.3.17 void∗ DMA_getControlBase ( void )
Gets the base address for the channel control table.
This function gets the base address of the channel control table. This table resides in system
memory and holds control information for each DMA channel.
Returns
Returns a pointer to the base address of the channel control table.
7.3.3.18 uint32_t DMA_getErrorStatus ( void )
Gets the DMA error status.
This function returns the DMA error status. It should be called from within the DMA error interrupt
handler to determine if a DMA error occurred.
Returns
Returns non-zero if a DMA error is pending.
7.3.3.19 uint32_t DMA_getInterruptStatus ( void )
Gets the DMA controller channel interrupt status for interrupt zero.
This function is used to get the interrupt status of the DMA controller. The returned value is a 32-bit
bit mask that indicates which channels are requesting an interrupt. This function can be used from
within an interrupt handler to determine or confirm which DMA channel has requested an interrupt.
Thu Jan 21 2016 12:34:41 AM
94
Direct Memory Access Controller (DMA)
Note that this will only apply to interrupt zero for the DMA controller as only one interrupt can be
associated with interrupts one through three. If an interrupt is assigned to an interrupt other than
interrupt zero, it will be masked by this function.
Returns
Returns a 32-bit mask which indicates requesting DMA channels. There is a bit for each
channel and a 1 indicates that the channel is requesting an interrupt. Multiple bits can be set.
7.3.3.20 bool DMA_isChannelEnabled ( uint32_t channelNum )
Checks if a DMA channel is enabled for operation.
Parameters
channelNum
is the channel number to check.
This function checks to see if a specific DMA channel is enabled. This function can be used to
check the status of a transfer, as the channel is automatically disabled at the end of a transfer.
Returns
Returns true if the channel is enabled, false if disabled.
7.3.3.21 void DMA_registerInterrupt ( uint32_t intChannel, void(∗)(void) intHandler )
Registers an interrupt handler for the DMA controller.
Parameters
interruptNumber
intHandler
identifies which DMA interrupt is to be registered.
is a pointer to the function to be called when the interrupt is called.
This function registers and enables the handler to be called when the DMA controller generates an
interrupt. The interrupt parameter should be one of the following:
DMA_INT0 the master DMA interrupt handler
DMA_INT1 the first configurable DMA interrupt handler
DMA_INT2 the second configurable DMA interrupt handler
DMA_INT3 the third configurable DMA interrupt handler
DMA_INTERR the third configurable DMA interrupt handler
See Also
Interrupt_registerInterrupt() for important information about registering interrupt handlers.
Returns
None.
References Interrupt_enableInterrupt(), and Interrupt_registerInterrupt().
7.3.3.22 void DMA_requestChannel ( uint32_t channelNum )
Requests a DMA channel to start a transfer.
Thu Jan 21 2016 12:34:41 AM
95
Direct Memory Access Controller (DMA)
Parameters
channelNum
is the channel number on which to request a DMA transfer.
This function allows software to request a DMA channel to begin a transfer. This function could be
used for performing a memory-to-memory transfer, or if for some reason a transfer needs to be
initiated by software instead of the peripheral associated with that channel.
Returns
None.
7.3.3.23 void DMA_requestSoftwareTransfer ( uint32_t channel )
Initializes a software transfer of the corresponding DMA channel. This is done if the user wants to
force a DMA on the specified channel without the hardware precondition. Specific channels can
be configured using the DMA_assignChannel function.
Parameters
channel
is the channel to trigger the interrupt
Returns
None
7.3.3.24 void DMA_setChannelControl ( uint32_t channelStructIndex, uint32_t control )
Sets the control parameters for a DMA channel control structure.
Parameters
channelStructIndex
control
is the logical OR of the DMA channel number with UDMA_PRI_SELECT or
UDMA_ALT_SELECT.
is logical OR of several control values to set the control parameters for the channel.
This function is used to set control parameters for a DMA transfer. These parameters are typically
not changed often.
The channelStructIndex parameter should be the logical OR of the channel number with one of
UDMA_PRI_SELECT or UDMA_ALT_SELECT to choose whether the primary or alternate data
structure is used.
The control parameter is the logical OR of five values: the data size, the source address
increment, the destination address increment, the arbitration size, and the use burst flag. The
choices available for each of these values is described below.
Choose the data size from one of UDMA_SIZE_8, UDMA_SIZE_16, or UDMA_SIZE_32 to select
a data size of 8, 16, or 32 bits.
Choose the source address increment from one of UDMA_SRC_INC_8, UDMA_SRC_INC_16,
UDMA_SRC_INC_32, or UDMA_SRC_INC_NONE to select an address increment of 8-bit bytes,
16-bit half-words, 32-bit words, or to select non-incrementing.
Choose the destination address increment from one of UDMA_DST_INC_8,
UDMA_DST_INC_16, UDMA_DST_INC_32, or UDMA_SRC_INC_8 to select an address
increment of 8-bit bytes, 16-bit half-words, 32-bit words, or to select non-incrementing.
Thu Jan 21 2016 12:34:41 AM
96
Direct Memory Access Controller (DMA)
The arbitration size determines how many items are transferred before the DMA controller
re-arbitrates for the bus. Choose the arbitration size from one of UDMA_ARB_1, UDMA_ARB_2,
UDMA_ARB_4, UDMA_ARB_8, through UDMA_ARB_1024 to select the arbitration size from 1
to 1024 items, in powers of 2.
The value UDMA_NEXT_USEBURST is used to force the channel to only respond to burst
requests at the tail end of a scatter-gather transfer.
Note
The address increment cannot be smaller than the data size.
Returns
None.
7.3.3.25 void DMA_setChannelScatterGather ( uint32_t channelNum, uint32_t taskCount,
void ∗ taskList, uint32_t isPeriphSG )
Configures a DMA channel for scatter-gather mode.
Parameters
channelNum
taskCount
taskList
isPeriphSG
is the DMA channel number.
is the number of scatter-gather tasks to execute.
is a pointer to the beginning of the scatter-gather task list.
is a flag to indicate it is a peripheral scatter-gather transfer (else it is memory scattergather transfer)
This function is used to configure a channel for scatter-gather mode. The caller must have already
set up a task list and must pass a pointer to the start of the task list as the taskList parameter. The
taskCount parameter is the count of tasks in the task list, not the size of the task list. The flag
bIsPeriphSG should be used to indicate if scatter-gather should be configured for peripheral or
memory operation.
See Also
DMA_TaskStructEntry
Returns
None.
7.3.3.26 void DMA_setChannelTransfer ( uint32_t channelStructIndex, uint32_t mode,
void ∗ srcAddr, void ∗ dstAddr, uint32_t transferSize )
Sets the transfer parameters for a DMA channel control structure.
Parameters
channelStructIndex
Thu Jan 21 2016 12:34:41 AM
is the logical OR of the DMA channel number with either UDMA_PRI_SELECT or
UDMA_ALT_SELECT.
97
Direct Memory Access Controller (DMA)
mode
srcAddr
dstAddr
transferSize
is the type of DMA transfer.
is the source address for the transfer.
is the destination address for the transfer.
is the number of data items to transfer.
This function is used to configure the parameters for a DMA transfer. These parameters are
typically changed often. The function DMA_setChannelControl() MUST be called at least once for
this channel prior to calling this function.
The channelStructIndex parameter should be the logical OR of the channel number with one of
UDMA_PRI_SELECT or UDMA_ALT_SELECT to choose whether the primary or alternate data
structure is used.
The mode parameter should be one of the following values:
UDMA_MODE_STOP stops the DMA transfer. The controller sets the mode to this value at
the end of a transfer.
UDMA_MODE_BASIC to perform a basic transfer based on request.
UDMA_MODE_AUTO to perform a transfer that always completes once started even if the
request is removed.
UDMA_MODE_PINGPONG to set up a transfer that switches between the primary and
alternate control structures for the channel. This mode allows use of ping-pong buffering for
DMA transfers.
UDMA_MODE_MEM_SCATTER_GATHER to set up a memory scatter-gather transfer.
UDMA_MODE_PER_SCATTER_GATHER to set up a peripheral scatter-gather transfer.
The srcAddr and dstAddr parameters are pointers to the first location of the data to be transferred.
These addresses should be aligned according to the item size. The compiler takes care of this
alignment if the pointers are pointing to storage of the appropriate data type.
The transferSize parameter is the number of data items, not the number of bytes.
The two scatter-gather modes, memory and peripheral, are actually different depending on
whether the primary or alternate control structure is selected. This function looks for the
UDMA_PRI_SELECT and UDMA_ALT_SELECT flag along with the channel number and sets the
scatter-gather mode as appropriate for the primary or alternate control structure.
The channel must also be enabled using DMA_enableChannel() after calling this function. The
transfer does not begin until the channel has been configured and enabled. Note that the channel
is automatically disabled after the transfer is completed, meaning that DMA_enableChannel() must
be called again after setting up the next transfer.
Note
Great care must be taken to not modify a channel control structure that is in use or else the
results are unpredictable, including the possibility of undesired data transfers to or from
memory or peripherals. For BASIC and AUTO modes, it is safe to make changes when the
channel is disabled, or the DMA_getChannelMode() returns UDMA_MODE_STOP. For
PINGPONG or one of the SCATTER_GATHER modes, it is safe to modify the primary or
alternate control structure only when the other is being used. The DMA_getChannelMode()
function returns UDMA_MODE_STOP when a channel control structure is inactive and safe
to modify.
Returns
None.
Thu Jan 21 2016 12:34:41 AM
98
Direct Memory Access Controller (DMA)
7.3.3.27 void DMA_setControlBase ( void ∗ controlTable )
Sets the base address for the channel control table.
Thu Jan 21 2016 12:34:41 AM
99
Direct Memory Access Controller (DMA)
Parameters
controlTable
is a pointer to the 1024-byte-aligned base address of the DMA channel control table.
This function configures the base address of the channel control table. This table resides in
system memory and holds control information for each DMA channel. The table must be aligned
on a 1024-byte boundary. The base address must be configured before any of the channel
functions can be used.
The size of the channel control table depends on the number of DMA channels and the transfer
modes that are used. Refer to the introductory text and the microcontroller datasheet for more
information about the channel control table.
Returns
None.
7.3.3.28 void DMA_unregisterInterrupt ( uint32_t intChannel )
Unregisters an interrupt handler for the DMA controller.
Parameters
interruptNumber
identifies which DMA interrupt to unregister.
This function disables and unregisters the handler to be called for the specified DMA interrupt.
The interrupt parameter should be one of the parameters as documented for the function
DMA_registerInterrupt().
Note fore interrupts that are associated with a specific DMA channel (DMA_INT1 - DMA_INT3),
this function will also disable that specific channel for interrupts.
See Also
Interrupt_registerInterrupt() for important information about registering interrupt handlers.
Returns
None.
References Interrupt_disableInterrupt(), and Interrupt_unregisterInterrupt().
Thu Jan 21 2016 12:34:41 AM
100
Flash Memory Controller (FlashCtl)
8
Flash Memory Controller (FlashCtl)
Module Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .101
Flash Limitations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .101
Verification Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ??
Programming Example . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .102
Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103
8.1
Module Operation
The MSP432 DriverLib Flash Controller peripheral is designed to simplify the process or writing,
erasing, and configuring the flash memory on the MSP432 part. Many of the stringent verification
requirements/preconditions are handled entirely inside the FlashCtl APIs.
8.2
Flash Controller Limitations
When utilizing the flash controller for MSP432, the user program has to take special consideration
on a few critical limitations. The biggest obstacle that the user has to be mindful of is the stringent
verification requirements imposed by the flash controller. Many operations (such as program and
verify) will take multiple cycles to complete successfully and the usage is somewhat complicated
for a normal user program. For this reason, it is strongly recommended that the user uses the
DriverLib APIs for programming and erasing flash. Using the flash controller directly is strongly
discouraged as the level of overhead and attention to verification requirements make for a very
intricate user experience.
Furthermore, when using the FlashCtl APIs, the user must take special consideration of where the
API is being executed. For the critical APIs (such as erase and program), the DriverLib APIs are
required to be executed from either SRAM or ROM (using the ROM_ prefix). Due to the verification
requirements of the flash controller, running these APIs out of Flash is not currently supported.
8.3
Wait State Considerations
When changing read modes on the MSP432 microcontroller, some read modes (such as erase
verify) require an additional number of wait states. The wait states of the flash controller can be
configured using the FlashCtl_setWaitState command. When using the DriverLib APIs, the wait
states are automatically changed within the API.
Thu Jan 21 2016 12:34:41 AM
101
Flash Memory Controller (FlashCtl)
8.4
Programming Example
The DriverLib package contains a variety of different code examples that demonstrate the usage
of the FlashCtl module. These code examples are accessible under the examples/ folder of the
MSPWare release as well as through TI Resource Explorer if using Code Composer Studio.
These code examples provide a comprehensive list of use cases as well as practical applications
involving each module.
Below is a very brief code example showing how to unprotect a sector and issue a mass erase
with the FlashCtl module:
/* Unprotecting User Bank 1, Sectors 30 and 31 */
MAP_FlashCtl_unprotectSector(FLASH_MAIN_MEMORY_SPACE_BANK1,
FLASH_SECTOR30 | FLASH_SECTOR31);
/* Trying a mass erase. Since we unprotected User Bank 1,
* sectors 31 and 32, this should erase these sectors. If it fails,
* trap inside an infinite loop.
*/
if(!MAP_FlashCtl_performMassErase())
while(1);
Thu Jan 21 2016 12:34:41 AM
we
102
Flash Memory Controller (FlashCtl)
8.5
Definitions
Functions
void FlashCtl_clearInterruptFlag (uint32_t flags)
void FlashCtl_clearProgramVerification (uint32_t verificationSetting)
void FlashCtl_disableInterrupt (uint32_t flags)
void FlashCtl_disableReadBuffering (uint_fast8_t memoryBank, uint_fast8_t accessMethod)
void FlashCtl_disableWordProgramming (void)
void FlashCtl_enableInterrupt (uint32_t flags)
void FlashCtl_enableReadBuffering (uint_fast8_t memoryBank, uint_fast8_t accessMethod)
void FlashCtl_enableWordProgramming (uint32_t mode)
bool FlashCtl_eraseSector (uint32_t addr)
uint32_t FlashCtl_getEnabledInterruptStatus (void)
uint32_t FlashCtl_getInterruptStatus (void)
void FlashCtl_getMemoryInfo (uint32_t addr, uint32_t ∗sectorNum, uint32_t ∗bankNum)
uint32_t FlashCtl_getReadMode (uint32_t flashBank)
uint32_t FlashCtl_getWaitState (uint32_t bank)
void FlashCtl_initiateMassErase (void)
void FlashCtl_initiateSectorErase (uint32_t addr)
bool FlashCtl_isSectorProtected (uint_fast8_t memorySpace, uint32_t sector)
uint32_t FlashCtl_isWordProgrammingEnabled (void)
bool FlashCtl_performMassErase (void)
bool FlashCtl_programMemory (void ∗src, void ∗dest, uint32_t length)
bool FlashCtl_protectSector (uint_fast8_t memorySpace, uint32_t sectorMask)
void FlashCtl_registerInterrupt (void(∗intHandler)(void))
void FlashCtl_setProgramVerification (uint32_t verificationSetting)
bool FlashCtl_setReadMode (uint32_t flashBank, uint32_t readMode)
void FlashCtl_setWaitState (uint32_t bank, uint32_t waitState)
bool FlashCtl_unprotectSector (uint_fast8_t memorySpace, uint32_t sectorMask)
void FlashCtl_unregisterInterrupt (void)
bool FlashCtl_verifyMemory (void ∗verifyAddr, uint32_t length, uint_fast8_t pattern)
8.5.1
Detailed Description
The code for this module is contained in driverlib/flash.c, with driverlib/flash.h
containing the API declarations for use by applications.
Thu Jan 21 2016 12:34:41 AM
103
Flash Memory Controller (FlashCtl)
8.5.2
Function Documentation
8.5.2.1
void FlashCtl_clearInterruptFlag ( uint32_t flags )
Clears flash system interrupt sources.
Parameters
flags
is a bit mask of the interrupt sources to be cleared. Must be a logical OR of:
FLASH_PROGRAM_ERROR,
FLASH_BENCHMARK_INT,
FLASH_ERASE_COMPLETE,
FLASH_BRSTPRGM_COMPLETE,
FLASH_WRDPRGM_COMPLETE,
FLASH_POSTVERIFY_FAILED,
FLASH_PREVERIFY_FAILED,
FLASH_BRSTRDCMP_COMPLETE
The specified flash system interrupt sources are cleared, so that they no longer assert. This
function must be called in the interrupt handler to keep it from being called again immediately
upon exit.
Note
Because there is a write buffer in the Cortex-M processor, it may take several clock cycles
before the interrupt source is actually cleared. Therefore, it is recommended that the
interrupt source be cleared early in the interrupt handler (as opposed to the very last action)
to avoid returning from the interrupt handler before the interrupt source is actually cleared.
Failure to do so may result in the interrupt handler being immediately reentered (because the
interrupt controller still sees the interrupt source asserted).
The interrupt sources vary based on the part in use. Please consult the data sheet for the
part you are using to determine which interrupt sources are available.
Thu Jan 21 2016 12:34:41 AM
104
Flash Memory Controller (FlashCtl)
Returns
None.
8.5.2.2
void FlashCtl_clearProgramVerification ( uint32_t verificationSetting )
Clears pre/post verification of burst and regular flash programming instructions. Note that this API
is for advanced users that are programming their own flash drivers. The program/erase APIs are
not affected by this setting and take care of the verification requirements.
Parameters
verificationSetting
Verification setting to clear. This value can be a bitwise OR of the following values:
FLASH_BURSTPOST,
FLASH_BURSTPRE,
FLASH_REGPRE,
FLASH_REGPOST
FLASH_NOVER No verification enabled
FLASH_FULLVER Full verification enabled
Returns
none
8.5.2.3
void FlashCtl_disableInterrupt ( uint32_t flags )
Disables individual flash system interrupt sources.
Parameters
flags
is a bit mask of the interrupt sources to be disabled. Must be a logical OR of:
FLASH_PROGRAM_ERROR,
FLASH_BENCHMARK_INT,
FLASH_ERASE_COMPLETE,
FLASH_BRSTPRGM_COMPLETE,
FLASH_WRDPRGM_COMPLETE,
FLASH_POSTVERIFY_FAILED,
FLASH_PREVERIFY_FAILED,
FLASH_BRSTRDCMP_COMPLETE
This function disables the indicated flash system interrupt sources. Only the sources that are
enabled can be reflected to the processor interrupt; disabled sources have no effect on the
processor.
Returns
None.
Thu Jan 21 2016 12:34:41 AM
105
Flash Memory Controller (FlashCtl)
8.5.2.4
void FlashCtl_disableReadBuffering ( uint_fast8_t memoryBank, uint_fast8_t
accessMethod )
Disables read buffering on accesses to a specified bank of flash memory
Thu Jan 21 2016 12:34:41 AM
106
Flash Memory Controller (FlashCtl)
Parameters
memoryBank
is the value of the memory bank to disable read buffering. Must be only one of the following
values:
FLASH_BANK0,
FLASH_BANK1
accessMethod
is the value of the access type to disable read buffering. Must ne only one of the following
values:
FLASH_DATA_READ,
FLASH_INSTRUCTION_FETCH
Returns
None.
8.5.2.5
void FlashCtl_disableWordProgramming ( void )
Disables word programming of flash memory.
Refer to FlashCtl_enableWordProgramming and the user’s guide for description on the difference
between full word and immediate programming
Returns
None.
Referenced by FlashCtl_programMemory().
8.5.2.6
void FlashCtl_enableInterrupt ( uint32_t flags )
Enables individual flash control interrupt sources.
Parameters
flags
is a bit mask of the interrupt sources to be enabled. Must be a logical OR of:
FLASH_PROGRAM_ERROR,
FLASH_BENCHMARK_INT,
FLASH_ERASE_COMPLETE,
FLASH_BRSTPRGM_COMPLETE,
FLASH_WRDPRGM_COMPLETE,
FLASH_POSTVERIFY_FAILED,
FLASH_PREVERIFY_FAILED,
FLASH_BRSTRDCMP_COMPLETE
This function enables the indicated flash system interrupt sources. Only the sources that are
enabled can be reflected to the processor interrupt; disabled sources have no effect on the
processor.
Thu Jan 21 2016 12:34:41 AM
107
Flash Memory Controller (FlashCtl)
Note
The interrupt sources vary based on the part in use. Please consult the data sheet for the
part you are using to determine which interrupt sources are available.
Returns
None.
8.5.2.7
void FlashCtl_enableReadBuffering ( uint_fast8_t memoryBank, uint_fast8_t
accessMethod )
Enables read buffering on accesses to a specified bank of flash memory
Parameters
memoryBank
is the value of the memory bank to enable read buffering. Must be only one of the following
values:
FLASH_BANK0,
FLASH_BANK1
accessMethod
is the value of the access type to enable read buffering. Must be only one of the following
values:
FLASH_DATA_READ,
FLASH_INSTRUCTION_FETCH
Returns
None.
8.5.2.8
void FlashCtl_enableWordProgramming ( uint32_t mode )
Enables word programming of flash memory.
This function will enable word programming of the flash memory and set the mode of behavior
when the flash write occurs.
Parameters
mode
The mode specifies the behavior of the flash controller when programming words to flash.
In FLASH_IMMEDIATE_WRITE_MODE, the program operation happens immediately on
the write to flash while in FLASH_COLLATED_WRITE_MODE the write will be delayed
until a full 128-bits have been collated. Possible values include:
FLASH_IMMEDIATE_WRITE_MODE
FLASH_COLLATED_WRITE_MODE
Refer to the user’s guide for further documentation.
Returns
none
Referenced by FlashCtl_programMemory().
Thu Jan 21 2016 12:34:41 AM
108
Flash Memory Controller (FlashCtl)
8.5.2.9
bool FlashCtl_eraseSector ( uint32_t addr )
Erases a sector of MAIN or INFO flash memory.
Thu Jan 21 2016 12:34:41 AM
109
Flash Memory Controller (FlashCtl)
Parameters
addr
The start of the sector to erase. Note that with flash, the minimum allowed size that can
be erased is a flash sector (which is 4KB on the MSP432 family). If an address is provided
to this function which is not on a 4KB boundary, the entire sector will still be erased.
Note
This function is blocking and will not exit until operation has either completed or failed due to
an error. Furthermore, given the complex verification requirements of the flash controller,
master interrupts are disabled throughout execution of this function. The original interrupt
context is saved at the start of execution and restored prior to exit of the API.
Due to the hardware limitations of the flash controller, this function cannot erase a memory
adress in the same flash bank that it is executing from. If using the ROM version of this API
(by using the (ROM_ or MAP_ prefixes) this is a don’t care, however if this API resides in
flash then special care needs to be taken to ensure no code execution or reads happen in
the flash bank being programmed while this API is being executed.
Returns
true if sector erase is successful, false otherwise.
References FlashCtl_verifyMemory(), Interrupt_disableMaster(), Interrupt_enableMaster(), and
SysCtl_getTLVInfo().
Referenced by FlashCtl_performMassErase().
8.5.2.10 uint32_t FlashCtl_getEnabledInterruptStatus ( void )
Gets the current interrupt status masked with the enabled interrupts. This function is useful to call
in ISRs to get a list of pending interrupts that are actually enabled and could have caused the ISR.
Returns
The current interrupt status, enumerated as a bit field of
FLASH_PROGRAM_ERROR,
FLASH_BENCHMARK_INT,
FLASH_ERASE_COMPLETE,
FLASH_BRSTPRGM_COMPLETE,
FLASH_WRDPRGM_COMPLETE,
FLASH_POSTVERIFY_FAILED,
FLASH_PREVERIFY_FAILED,
FLASH_BRSTRDCMP_COMPLETE
Note
The interrupt sources vary based on the part in use. Please consult the data sheet for the
part you are using to determine which interrupt sources are available.
References FlashCtl_getInterruptStatus().
8.5.2.11 uint32_t FlashCtl_getInterruptStatus ( void )
Gets the current interrupt status.
Thu Jan 21 2016 12:34:41 AM
110
Flash Memory Controller (FlashCtl)
Returns
The current interrupt status, enumerated as a bit field of:
FLASH_PROGRAM_ERROR,
FLASH_BENCHMARK_INT,
FLASH_ERASE_COMPLETE,
FLASH_BRSTPRGM_COMPLETE,
FLASH_WRDPRGM_COMPLETE,
FLASH_POSTVERIFY_FAILED,
FLASH_PREVERIFY_FAILED,
FLASH_BRSTRDCMP_COMPLETE
Note
The interrupt sources vary based on the part in use. Please consult the data sheet for the
part you are using to determine which interrupt sources are available.
Referenced by FlashCtl_getEnabledInterruptStatus().
8.5.2.12 void FlashCtl_getMemoryInfo ( uint32_t addr, uint32_t ∗ sectorNum, uint32_t ∗
bankNum )
Calculates the flash bank and sector number given an address. Stores the results into the two
pointers given as parameters. The user must provide a valid memory address (an address in
SRAM for example will give an invalid result).
Parameters
addr
sectorNum
sectorNum
Address to calculate the bank/sector information for
The sector number will be stored in here after the function completes.
The bank number will be stored in here after the function completes.
Note
For simplicity, this API only works with address in MAIN flash memory. For calculating the
sector/bank number of an address in info memory, please refer to your device datasheet/
Returns
None.
References SysCtl_getFlashSize().
8.5.2.13 uint32_t FlashCtl_getReadMode ( uint32_t flashBank )
Gets the flash read mode to be used by default flash read operations.
Parameters
flashBank
Flash bank to set read mode for. Valid values are:
FLASH_BANK0
FLASH_BANK1
Thu Jan 21 2016 12:34:41 AM
111
Flash Memory Controller (FlashCtl)
Returns
Returns the read mode to set. Valid values are:
FLASH_NORMAL_READ_MODE,
FLASH_MARGIN0_READ_MODE,
FLASH_MARGIN1_READ_MODE,
FLASH_PROGRAM_VERIFY_READ_MODE,
FLASH_ERASE_VERIFY_READ_MODE,
FLASH_LEAKAGE_VERIFY_READ_MODE,
FLASH_MARGIN0B_READ_MODE,
FLASH_MARGIN1B_READ_MODE
Referenced by FlashCtl_verifyMemory().
8.5.2.14 uint32_t FlashCtl_getWaitState ( uint32_t bank )
Returns the set number of flash wait states for the given flash bank.
Parameters
flashBank
Flash bank to set wait state for. Valid values are:
FLASH_BANK0
FLASH_BANK1
Returns
The wait state setting for the specified flash bank
Referenced by FlashCtl_verifyMemory().
8.5.2.15 void FlashCtl_initiateMassErase ( void )
Initiates a mass erase and returns control back to the program. This is a non-blocking function,
however it is the user’s responsibility to perform the necessary verification requirements after the
interrupt is set to signify completion.
Returns
None
8.5.2.16 void FlashCtl_initiateSectorErase ( uint32_t addr )
Initiates a sector erase of MAIN or INFO flash memory. Note that this function simply initaites the
sector erase, but does no verification which is required by the flash controller. The user must
manually set and enable interrupts on the flash controller to fire on erase completion and then use
the FlashCtl_verifyMemory function to verify that the sector was actually erased
Thu Jan 21 2016 12:34:41 AM
112
Flash Memory Controller (FlashCtl)
Parameters
addr
The start of the sector to erase. Note that with flash, the minimum allowed size that can
be erased is a flash sector (which is 4KB on the MSP432 family). If an address is provided
to this function which is not on a 4KB boundary, the entire sector will still be erased.
Returns
None
8.5.2.17 bool FlashCtl_isSectorProtected ( uint_fast8_t memorySpace, uint32_t sector )
Returns the sector protection for given sector mask and memory space
Thu Jan 21 2016 12:34:41 AM
113
Flash Memory Controller (FlashCtl)
Parameters
memorySpace
is the value of the memory bank to check for program protection. Must be only one of the
following values:
FLASH_MAIN_MEMORY_SPACE_BANK0,
FLASH_MAIN_MEMORY_SPACE_BANK1,
FLASH_INFO_MEMORY_SPACE_BANK0,
FLASH_INFO_MEMORY_SPACE_BANK1
sector
is the sector to check for program protection. Must be one of the following values:
FLASH_SECTOR0,
FLASH_SECTOR1,
FLASH_SECTOR2,
FLASH_SECTOR3,
FLASH_SECTOR4,
FLASH_SECTOR5,
FLASH_SECTOR6,
FLASH_SECTOR7,
FLASH_SECTOR8,
FLASH_SECTOR9,
FLASH_SECTOR10,
FLASH_SECTOR11,
FLASH_SECTOR12,
FLASH_SECTOR13,
FLASH_SECTOR14,
FLASH_SECTOR15,
FLASH_SECTOR16,
FLASH_SECTOR17,
FLASH_SECTOR18,
FLASH_SECTOR19,
FLASH_SECTOR20,
FLASH_SECTOR21,
FLASH_SECTOR22,
FLASH_SECTOR23,
FLASH_SECTOR24,
FLASH_SECTOR25,
FLASH_SECTOR26,
FLASH_SECTOR27,
FLASH_SECTOR28,
FLASH_SECTOR29,
FLASH_SECTOR30,
FLASH_SECTOR31
Thu Jan 21 2016 12:34:41 AM
114
Flash Memory Controller (FlashCtl)
Note that flash sector sizes are 4KB and the number of sectors may vary depending on the
specific device. Also, for INFO memory space, only sectors FLASH_SECTOR0 and
FLASH_SECTOR1 will exist.
Note
Not all devices will contain a dedicated INFO memory. Please check the device datasheet to
see if your device has INFO memory available for use. For devices without INFO memory,
any operation related to the INFO memory will be ignored by the hardware.
Returns
true if sector protection enabled false otherwise.
Referenced by FlashCtl_protectSector(), and FlashCtl_unprotectSector().
8.5.2.18 uint32_t FlashCtl_isWordProgrammingEnabled ( void )
Returns if word programming mode is enabled (and if it is, the specific mode)
Refer to FlashCtl_enableWordProgramming and the user’s guide for description on the difference
between full word and immediate programming
Returns
a zero value if word programming is disabled,
FLASH_IMMEDIATE_WRITE_MODE
FLASH_COLLATED_WRITE_MODE
8.5.2.19 bool FlashCtl_performMassErase ( void )
Performs a mass erase on all unprotected flash sectors. Protected sectors are ignored.
Note
This function is blocking and will not exit until operation has either completed or failed due to
an error. Furthermore, given the complex verification requirements of the flash controller,
master interrupts are disabled throughout execution of this function. The original interrupt
context is saved at the start of execution and restored prior to exit of the API.
Due to the hardware limitations of the flash controller, this function cannot erase a memory
adress in the same flash bank that it is executing from. If using the ROM version of this API
(by using the (ROM_ or MAP_ prefixes) this is a don’t care, however if this API resides in
flash then special care needs to be taken to ensure no code execution or reads happen in
the flash bank being programmed while this API is being executed.
Returns
true if mass erase completes successfully, false otherwise
References FlashCtl_eraseSector(), FlashCtl_verifyMemory(), Interrupt_disableMaster(),
Interrupt_enableMaster(), and SysCtl_getFlashSize().
8.5.2.20 bool FlashCtl_programMemory ( void ∗ src, void ∗ dest, uint32_t length )
Program a portion of flash memory with the provided data
Thu Jan 21 2016 12:34:41 AM
115
Flash Memory Controller (FlashCtl)
Parameters
src
dest
length
Pointer to the data source to program into flash
Pointer to the destination in flash to program
Length in bytes to program
Note
There are no sector/boundary restrictions for this function, however it is encouraged to
proved a start address aligned on 32-bit boundaries. Providing an unaligned address will
result in unaligned data accesses and detriment efficiency.
This function is blocking and will not exit until operation has either completed or failed due to
an error. Furthermore, given the complex verification requirements of the flash controller,
master interrupts are disabled throughout execution of this function. The original interrupt
context is saved at the start of execution and restored prior to exit of the API.
Due to the hardware limitations of the flash controller, this function cannot program a
memory adress in the same flash bank that it is executing from. If using the ROM version of
this API (by using the (ROM_ or MAP_ prefixes) this is a don’t care, however if this API
resides in flash then special care needs to be taken to ensure no code execution or reads
happen in the flash bank being programmed while this API is being executed.
Returns
Whether or not the program succeeded
References FlashCtl_disableWordProgramming(), FlashCtl_enableWordProgramming(),
Interrupt_disableMaster(), Interrupt_enableMaster(), and SysCtl_getTLVInfo().
8.5.2.21 bool FlashCtl_protectSector ( uint_fast8_t memorySpace, uint32_t sectorMask )
Enables program protection on the given sector mask. This setting can be applied on a
sector-wise bases on a given memory space (INFO or MAIN).
Parameters
memorySpace
is the value of the memory bank to enable program protection. Must be only one of the
following values:
FLASH_MAIN_MEMORY_SPACE_BANK0,
FLASH_MAIN_MEMORY_SPACE_BANK1,
FLASH_INFO_MEMORY_SPACE_BANK0,
FLASH_INFO_MEMORY_SPACE_BANK1
Thu Jan 21 2016 12:34:41 AM
116
Flash Memory Controller (FlashCtl)
sectorMask
is a bit mask of the sectors to enable program protection. Must be a bitfield of the following
values:
FLASH_SECTOR0,
FLASH_SECTOR1,
FLASH_SECTOR2,
FLASH_SECTOR3,
FLASH_SECTOR4,
FLASH_SECTOR5,
FLASH_SECTOR6,
FLASH_SECTOR7,
FLASH_SECTOR8,
FLASH_SECTOR9,
FLASH_SECTOR10,
FLASH_SECTOR11,
FLASH_SECTOR12,
FLASH_SECTOR13,
FLASH_SECTOR14,
FLASH_SECTOR15,
FLASH_SECTOR16,
FLASH_SECTOR17,
FLASH_SECTOR18,
FLASH_SECTOR19,
FLASH_SECTOR20,
FLASH_SECTOR21,
FLASH_SECTOR22,
FLASH_SECTOR23,
FLASH_SECTOR24,
FLASH_SECTOR25,
FLASH_SECTOR26,
FLASH_SECTOR27,
FLASH_SECTOR28,
FLASH_SECTOR29,
FLASH_SECTOR30,
FLASH_SECTOR31
Thu Jan 21 2016 12:34:41 AM
117
Flash Memory Controller (FlashCtl)
Note
Flash sector sizes are 4KB and the number of sectors may vary depending on the specific
device. Also, for INFO memory space, only sectors FLASH_SECTOR0 and
FLASH_SECTOR1 will exist.
Not all devices will contain a dedicated INFO memory. Please check the device datasheet to
see if your device has INFO memory available for use. For devices without INFO memory,
any operation related to the INFO memory will be ignored by the hardware.
Returns
true if sector protection enabled false otherwise.
References FlashCtl_isSectorProtected().
8.5.2.22 void FlashCtl_registerInterrupt ( void(∗)(void) intHandler )
Registers an interrupt handler for flash clock system interrupt.
Parameters
intHandler
is a pointer to the function to be called when the clock system interrupt occurs.
This function registers the handler to be called when a clock system interrupt occurs. This function
enables the global interrupt in the interrupt controller; specific flash controller interrupts must be
enabled via FlashCtl_enableInterrupt(). It is the interrupt handler’s responsibility to clear the
interrupt source via FlashCtl_clearInterruptFlag().
See Also
Interrupt_registerInterrupt() for important information about registering interrupt handlers.
Returns
None.
References Interrupt_enableInterrupt(), and Interrupt_registerInterrupt().
8.5.2.23 void FlashCtl_setProgramVerification ( uint32_t verificationSetting )
Setups pre/post verification of burst and regular flash programming instructions. Note that this API
is for advanced users that are programming their own flash drivers. The program/erase APIs are
not affected by this setting and take care of the verification requirements.
Parameters
verificationSetting
Verification setting to set. This value can be a bitwise OR of the following values:
FLASH_BURSTPOST,
FLASH_BURSTPRE,
FLASH_REGPRE,
FLASH_REGPOST
FLASH_NOVER No verification enabled
FLASH_FULLVER Full verification enabled
Thu Jan 21 2016 12:34:41 AM
118
Flash Memory Controller (FlashCtl)
Returns
none
8.5.2.24 bool FlashCtl_setReadMode ( uint32_t flashBank, uint32_t readMode )
Sets the flash read mode to be used by default flash read operations. Note that the proper wait
states must be set prior to entering this function.
Parameters
flashBank
Flash bank to set read mode for. Valid values are:
FLASH_BANK0
FLASH_BANK1
readMode
The read mode to set. Valid values are:
FLASH_NORMAL_READ_MODE,
FLASH_MARGIN0_READ_MODE,
FLASH_MARGIN1_READ_MODE,
FLASH_PROGRAM_VERIFY_READ_MODE,
FLASH_ERASE_VERIFY_READ_MODE,
FLASH_LEAKAGE_VERIFY_READ_MODE,
FLASH_MARGIN0B_READ_MODE,
FLASH_MARGIN1B_READ_MODE
Returns
None.
Referenced by FlashCtl_verifyMemory().
8.5.2.25 void FlashCtl_setWaitState ( uint32_t bank, uint32_t waitState )
Changes the number of wait states that are used by the flash controller for read operations. When
changing frequency ranges of the clock, this functions must be used in order to allow for readable
flash memory.
Parameters
waitState
flashBank
The number of wait states to set. Note that only bits 0-3 are used.
Flash bank to set wait state for. Valid values are:
FLASH_BANK0
FLASH_BANK1
Referenced by FlashCtl_verifyMemory().
Thu Jan 21 2016 12:34:41 AM
119
Flash Memory Controller (FlashCtl)
8.5.2.26 bool FlashCtl_unprotectSector ( uint_fast8_t memorySpace, uint32_t sectorMask
)
Disables program protection on the given sector mask. This setting can be applied on a
sector-wise bases on a given memory space (INFO or MAIN).
Thu Jan 21 2016 12:34:41 AM
120
Flash Memory Controller (FlashCtl)
Parameters
memorySpace
is the value of the memory bank to disable program protection. Must be only one of the
following values:
FLASH_MAIN_MEMORY_SPACE_BANK0,
FLASH_MAIN_MEMORY_SPACE_BANK1,
FLASH_INFO_MEMORY_SPACE_BANK0,
FLASH_INFO_MEMORY_SPACE_BANK1
sectorMask
is a bit mask of the sectors to disable program protection. Must be a bitfield of the following
values:
FLASH_SECTOR0,
FLASH_SECTOR1,
FLASH_SECTOR2,
FLASH_SECTOR3,
FLASH_SECTOR4,
FLASH_SECTOR5,
FLASH_SECTOR6,
FLASH_SECTOR7,
FLASH_SECTOR8,
FLASH_SECTOR9,
FLASH_SECTOR10,
FLASH_SECTOR11,
FLASH_SECTOR12,
FLASH_SECTOR13,
FLASH_SECTOR14,
FLASH_SECTOR15,
FLASH_SECTOR16,
FLASH_SECTOR17,
FLASH_SECTOR18,
FLASH_SECTOR19,
FLASH_SECTOR20,
FLASH_SECTOR21,
FLASH_SECTOR22,
FLASH_SECTOR23,
FLASH_SECTOR24,
FLASH_SECTOR25,
FLASH_SECTOR26,
FLASH_SECTOR27,
FLASH_SECTOR28,
FLASH_SECTOR29,
FLASH_SECTOR30,
FLASH_SECTOR31
Thu Jan 21 2016 12:34:41 AM
121
Flash Memory Controller (FlashCtl)
Note
Flash sector sizes are 4KB and the number of sectors may vary depending on the specific
device. Also, for INFO memory space, only sectors FLASH_SECTOR0 and
FLASH_SECTOR1 will exist.
Not all devices will contain a dedicated INFO memory. Please check the device datasheet to
see if your device has INFO memory available for use. For devices without INFO memory,
any operation related to the INFO memory will be ignored by the hardware.
Returns
true if sector protection disabled false otherwise.
References FlashCtl_isSectorProtected().
8.5.2.27 void FlashCtl_unregisterInterrupt ( void )
Unregisters the interrupt handler for the flash system.
This function unregisters the handler to be called when a clock system interrupt occurs. This
function also masks off the interrupt in the interrupt controller so that the interrupt handler no
longer is called.
See Also
Interrupt_registerInterrupt() for important information about registering interrupt handlers.
Returns
None.
References Interrupt_disableInterrupt(), and Interrupt_unregisterInterrupt().
8.5.2.28 bool FlashCtl_verifyMemory ( void ∗ verifyAddr, uint32_t length, uint_fast8_t
pattern )
Verifies a given segment of memory based off either a high (1) or low (0) state.
Parameters
verifyAddr
length
pattern
Start address where verification will begin
Length in bytes to verify based off the pattern
The pattern which verification will check versus. This can either be a low pattern (each
register will be checked versus a pattern of 32 zeros, or a high pattern (each register
will be checked versus a pattern of 32 ones). Valid values are: FLASH_0_PATTERN,
FLASH_1_PATTERN
Note
There are no sector/boundary restrictions for this function, however it is encouraged to
proved a start address aligned on 32-bit boundaries. Providing an unaligned address will
result in unaligned data accesses and detriment efficiency.
This function is blocking and will not exit until operation has either completed or failed due to
an error. Furthermore, given the complex verification requirements of the flash controller,
master interrupts are disabled throughout execution of this function. The original interrupt
context is saved at the start of execution and restored prior to exit of the API.
Thu Jan 21 2016 12:34:41 AM
122
Flash Memory Controller (FlashCtl)
Due to the hardware limitations of the flash controller, this function cannot verify a memory
adress in the same flash bank that it is executing from. If using the ROM version of this API
(by using the (ROM_ or MAP_ prefixes) this is a don’t care, however if this API resides in
flash then special care needs to be taken to ensure no code execution or reads happen in
the flash bank being programmed while this API is being executed.
Returns
true if memory verification is successful, false otherwise.
References FlashCtl_getReadMode(), FlashCtl_getWaitState(), FlashCtl_setReadMode(),
FlashCtl_setWaitState(), Interrupt_disableMaster(), Interrupt_enableMaster(), and
SysCtl_getFlashSize().
Referenced by FlashCtl_eraseSector(), and FlashCtl_performMassErase().
Thu Jan 21 2016 12:34:41 AM
123
Floating Point Unit (FPU)
9
Floating Point Unit (FPU)
Module Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .122
Programming Example . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .123
Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 124
9.1
Module Operation
The floating-point unit (FPU) driver provides methods for manipulating the behavior of the
floating-point unit in the Cortex-M processor. By default, the floating-point is disabled and must be
enabled prior to the execution of any floating-point instructions. If a floating-point instruction is
executed when the floating-point unit is disabled, a NOCP usage fault is generated. This feature
can be used by an RTOS, for example, to keep track of which tasks actually use the floating-point
unit, and therefore only perform floating-point context save/restore on task switches that involve
those tasks.
There are three methods of handling the floating-point context when the processor executes an
interrupt handler: it can do nothing with the floating-point context, it can always save the
floating-point context, or it can perform a lazy save/restore of the floating-point context. If nothing
is done with the floating-point context, the interrupt stack frame is identical to a Cortex-M
processor that does not have a floating-point unit, containing only the volatile registers of the
integer unit. This method is useful for applications where the floating-point unit is used by the main
thread of execution, but not in any of the interrupt handlers. By not saving the floating-point
context, stack usage is reduced and interrupt latency is kept to a minimum.
Alternatively, the floating-point context can always be saved onto the stack. This method allows
floating-point operations to be performed inside interrupt handlers without any special precautions,
at the expense of increased stack usage (for the floating-point context) and increased interrupt
latency (due to the additional writes to the stack). The advantage to this method is that the stack
frame always contains the floating-point context when inside an interrupt handler.
The default handling of the floating-point context is to perform a lazy save/restore. When an
interrupt is taken, space is reserved on the stack for the floating-point context but the context is not
written. This method keeps the interrupt latency to a minimum because only the integer state is
written to the stack. Then, if a floating-point instruction is executed from within the interrupt
handler, the floating-point context is written to the stack prior to the execution of the floating-point
instruction. Finally, upon return from the interrupt, the floating-point context is restored from the
stack only if it was written. Using lazy save/restore provides a blend between fast interrupt
response and the ability to use floating-point instructions in the interrupt handler.
The floating-point unit can generate an interrupt when one of several exceptions occur. The
exceptions are underflow, overflow, divide by zero, invalid operation, input denormal, and inexact
exception. The application can optionally choose to enable one or more of these interrupts and
use the interrupt handler to decide upon a course of action to be taken in each case.
The behavior of the floating-point unit can also be adjusted, specifying the format of half-precision
floating-point values, the handle of NaN values, the flush-to-zero mode (which sacrifices full IEEE
compliance for execution speed), and the rounding mode for results.
Thu Jan 21 2016 12:34:41 AM
124
Floating Point Unit (FPU)
9.2
Programming Example
The DriverLib package contains a variety of different code examples that demonstrate the usage
of the FPU module. These code examples are accessible under the examples/ folder of the
MSPWare release as well as through TI Resource Explorer if using Code Composer Studio.
These code examples provide a comprehensive list of use cases as well as practical applications
involving each module.
Below is a very brief example of floating point operation. While the compiler will usually enable the
floating point unit by default, when executing floating point operations it is important to make sure
that the coprocessor is enabled (otherwise a system fault will occur).
/* Enabling FPU for DCO Frequency calculation */
MAP_FPU_enableModule();
/* Setting the DCO Frequency to a non-standard 8.33MHz */
MAP_CS_setDCOFrequency(8330000);
Thu Jan 21 2016 12:34:41 AM
125
Floating Point Unit (FPU)
9.3
Definitions
Functions
void FPU_disableModule (void)
void FPU_disableStacking (void)
void FPU_enableLazyStacking (void)
void FPU_enableModule (void)
void FPU_enableStacking (void)
void FPU_setFlushToZeroMode (uint32_t mode)
void FPU_setHalfPrecisionMode (uint32_t mode)
void FPU_setNaNMode (uint32_t mode)
void FPU_setRoundingMode (uint32_t mode)
9.3.1
Detailed Description
The code for this module is contained in driverlib/fpu.c, with driverlib/fpu.h containing
the API declarations for use by applications.
Thu Jan 21 2016 12:34:41 AM
126
Floating Point Unit (FPU)
9.3.2
Function Documentation
9.3.2.1
void FPU_disableModule ( void )
Disables the floating-point unit.
This function disables the floating-point unit, preventing floating-point instructions from executing
(generating a NOCP usage fault instead).
Returns
None.
9.3.2.2
void FPU_disableStacking ( void )
Disables the stacking of floating-point registers.
This function disables the stacking of floating-point registers s0-s15 when an interrupt is handled.
When floating-point context stacking is disabled, floating-point operations performed in an interrupt
handler destroy the floating-point context of the main thread of execution.
Returns
None.
9.3.2.3
void FPU_enableLazyStacking ( void )
Enables the lazy stacking of floating-point registers.
This function enables the lazy stacking of floating-point registers s0-s15 when an interrupt is
handled. When lazy stacking is enabled, space is reserved on the stack for the floating-point
context, but the floating-point state is not saved. If a floating-point instruction is executed from
within the interrupt context, the floating-point context is first saved into the space reserved on the
stack. On completion of the interrupt handler, the floating-point context is only restored if it was
saved (as the result of executing a floating-point instruction).
This method provides a compromise between fast interrupt response (because the floating-point
state is not saved on interrupt entry) and the ability to use floating-point in interrupt handlers
(because the floating-point state is saved if floating-point instructions are used).
Returns
None.
9.3.2.4
void FPU_enableModule ( void )
Enables the floating-point unit.
This function enables the floating-point unit, allowing the floating-point instructions to be executed.
This function must be called prior to performing any hardware floating-point operations; failure to
do so results in a NOCP usage fault.
Thu Jan 21 2016 12:34:41 AM
127
Floating Point Unit (FPU)
Returns
None.
9.3.2.5
void FPU_enableStacking ( void )
Enables the stacking of floating-point registers.
This function enables the stacking of floating-point registers s0-s15 when an interrupt is handled.
When enabled, space is reserved on the stack for the floating-point context and the floating-point
state is saved into this stack space. Upon return from the interrupt, the floating-point context is
restored.
If the floating-point registers are not stacked, floating-point instructions cannot be safely executed
in an interrupt handler because the values of s0-s15 are not likely to be preserved for the
interrupted code. On the other hand, stacking the floating-point registers increases the stacking
operation from 8 words to 26 words, also increasing the interrupt response latency.
Returns
None.
9.3.2.6
void FPU_setFlushToZeroMode ( uint32_t mode )
Selects the flush-to-zero mode.
Parameters
mode
is the flush-to-zero mode;
FPU_FLUSH_TO_ZERO_EN.
which
is
either
FPU_FLUSH_TO_ZERO_DIS
This function enables or disables the flush-to-zero mode of the floating-point unit. When disabled
(the default), the floating-point unit is fully IEEE compliant. When enabled, values close to zero are
treated as zero, greatly improving the execution speed at the expense of some accuracy (as well
as IEEE compliance).
Note
Unless this function is called prior to executing any floating-point instructions, the default
mode is used.
Returns
None.
9.3.2.7
void FPU_setHalfPrecisionMode ( uint32_t mode )
Selects the format of half-precision floating-point values.
Parameters
Thu Jan 21 2016 12:34:41 AM
128
or
Floating Point Unit (FPU)
mode
is the format for half-precision floating-point value, which is either FPU_HALF_IEEE or
FPU_HALF_ALTERNATE.
This function selects between the IEEE half-precision floating-point representation and the
Cortex-M processor alternative representation. The alternative representation has a larger range
but does not have a way to encode infinity (positive or negative) or NaN (quiet or signalling). The
default setting is the IEEE format.
Note
Unless this function is called prior to executing any floating-point instructions, the default
mode is used.
Returns
None.
9.3.2.8
void FPU_setNaNMode ( uint32_t mode )
Selects the NaN mode.
Parameters
mode
is the mode for NaN results;
FPU_NAN_DEFAULT.
which is either FPU_NAN_PROPAGATE or
This function selects the handling of NaN results during floating-point computations. NaNs can
either propagate (the default), or they can return the default NaN.
Note
Unless this function is called prior to executing any floating-point instructions, the default
mode is used.
Returns
None.
9.3.2.9
void FPU_setRoundingMode ( uint32_t mode )
Selects the rounding mode for floating-point results.
Parameters
mode
is the rounding mode.
This function selects the rounding mode for floating-point results. After a floating-point operation,
the result is rounded toward the specified value. The default mode is FPU_ROUND_NEAREST.
The following rounding modes are available (as specified by mode):
FPU_ROUND_NEAREST - round toward the nearest value
FPU_ROUND_POS_INF - round toward positive infinity
FPU_ROUND_NEG_INF - round toward negative infinity
FPU_ROUND_ZERO - round toward zero
Thu Jan 21 2016 12:34:41 AM
129
Floating Point Unit (FPU)
Note
Unless this function is called prior to executing any floating-point instructions, the default
mode is used.
Returns
None.
Thu Jan 21 2016 12:34:41 AM
130
General Purpose Input/Output (GPIO)
10
General Purpose Input/Output (GPIO)
Module Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .129
Key Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 129
Programming Example . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .130
Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 131
10.1
Module Operation
The Digital I/O (GPIO) API provides a set of functions for using the MSPWare L GPIO modules.
Functions are provided to setup and enable use of input/output pins, setting them up with or
without interrupts and those that access the pin value.
10.2
Key Features
The digital I/O features include:
Independently programmable individual I/Os
Any combination of input or output
Individually configurable P1 and P2 interrupts. Some devices may include additional port
interrupts.
Independent input and output data registers
Individually configurable pullup or pulldown resistors
Devices within the family may have up to twelve digital I/O ports implemented (P1 to P11 and PJ).
Most ports contain eight I/O lines; however, some ports may contain less (see the device-specific
data sheet for ports available). Each I/O line is individually configurable for input or output
direction, and each can be individually read or written. Each I/O line is individually configurable for
pullup or pulldown resistors. PJ contains only four I/O lines.
Individual ports can be accessed as byte-wide ports or can be combined into word-wide ports and
accessed via word formats. Port pairs P1/P2, P3/P4, P5/P6, P7/P8, etc., are associated with the
names PA, PB, PC, PD, etc., respectively. All port registers are handled in this manner with this
naming convention.
When writing to port PA with word operations, all 16 bits are written to the port. When writing to
the lower byte of the PA port using byte operations, the upper byte remains unchanged. Similarly,
writing to the upper byte of the PA port using byte instructions leaves the lower byte unchanged.
When writing to a port that contains less than the maximum number of bits possible, the unused
bits are a "don’t care". Ports PB, PC, PD, PE, and PF behave similarly.
Reading of the PA port using word operations causes all 16 bits to be transferred to the
destination. Reading the lower or upper byte of the PA port (P1 or P2) and storing to memory
using byte operations causes only the lower or upper byte to be transferred to the destination,
respectively. Reading of the PA port and storing to a general-purpose register using byte
operations causes the byte transferred to be written to the least significant byte of the register. The
upper significant byte of the destination register is cleared automatically. Ports PB, PC, PD, PE,
Thu Jan 21 2016 12:34:41 AM
131
General Purpose Input/Output (GPIO)
and PF behave similarly. When reading from ports that contain less than the maximum bits
possible, unused bits are read as zeros (similarly for port PJ).
The GPIO pin may be configured as an I/O pin with GPIO_setAsOutputPin, GPIO_setAsInputPin,
GPIO_setAsInputPinWithPullDownResistor or GPIO_setAsInputPinWithPullUpResistor . The
GPIO pin may instead be configured to operate in the Peripheral Module assigned function by
configuring the GPIO using GPIO_setAsPeripheralModuleFunctionOutputPin or
GPIO_setAsPeripheralModuleFunctionInputPin.
10.3
Programming Example
The DriverLib package contains a variety of different code examples that demonstrate the usage
of the GPIO module. These code examples are accessible under the examples/ folder of the
MSPWare release as well as through TI Resource Explorer if using Code Composer Studio.
These code examples provide a comprehensive list of use cases as well as practical applications
involving each module.
Below is a simple example of how to set up a GPIO in output mode and toggle an LED using a
simple delay:
int main(void)
{
volatile uint32_t ii;
/* Halting the Watchdog */
MAP_WDT_A_holdTimer();
/* Configuring P1.0 as output */
MAP_GPIO_setAsOutputPin(GPIO_PORT_P1,
GPIO_PIN0);
while (1)
{
/* Delay Loop */
for(ii=0;ii<5000;ii++)
{
}
MAP_GPIO_toggleOutputOnPin(GPIO_PORT_P1,
GPIO_PIN0);
}
}
Thu Jan 21 2016 12:34:41 AM
132
General Purpose Input/Output (GPIO)
10.4
Definitions
Functions
void GPIO_clearInterruptFlag (uint_fast8_t selectedPort, uint_fast16_t selectedPins)
void GPIO_disableInterrupt (uint_fast8_t selectedPort, uint_fast16_t selectedPins)
void GPIO_enableInterrupt (uint_fast8_t selectedPort, uint_fast16_t selectedPins)
uint_fast16_t GPIO_getEnabledInterruptStatus (uint_fast8_t selectedPort)
uint8_t GPIO_getInputPinValue (uint_fast8_t selectedPort, uint_fast16_t selectedPins)
uint_fast16_t GPIO_getInterruptStatus (uint_fast8_t selectedPort, uint_fast16_t selectedPins)
void GPIO_interruptEdgeSelect (uint_fast8_t selectedPort, uint_fast16_t selectedPins,
uint_fast8_t edgeSelect)
void GPIO_registerInterrupt (uint_fast8_t selectedPort, void(∗intHandler)(void))
void GPIO_setAsInputPin (uint_fast8_t selectedPort, uint_fast16_t selectedPins)
void GPIO_setAsInputPinWithPullDownResistor (uint_fast8_t selectedPort, uint_fast16_t
selectedPins)
void GPIO_setAsInputPinWithPullUpResistor (uint_fast8_t selectedPort, uint_fast16_t
selectedPins)
void GPIO_setAsOutputPin (uint_fast8_t selectedPort, uint_fast16_t selectedPins)
void GPIO_setAsPeripheralModuleFunctionInputPin (uint_fast8_t selectedPort, uint_fast16_t
selectedPins, uint_fast8_t mode)
void GPIO_setAsPeripheralModuleFunctionOutputPin (uint_fast8_t selectedPort,
uint_fast16_t selectedPins, uint_fast8_t mode)
void GPIO_setDriveStrengthHigh (uint_fast8_t selectedPort, uint_fast8_t selectedPins)
void GPIO_setDriveStrengthLow (uint_fast8_t selectedPort, uint_fast8_t selectedPins)
void GPIO_setOutputHighOnPin (uint_fast8_t selectedPort, uint_fast16_t selectedPins)
void GPIO_setOutputLowOnPin (uint_fast8_t selectedPort, uint_fast16_t selectedPins)
void GPIO_toggleOutputOnPin (uint_fast8_t selectedPort, uint_fast16_t selectedPins)
void GPIO_unregisterInterrupt (uint_fast8_t selectedPort)
10.4.1 Detailed Description
The code for this module is contained in driverlib/gpio.c and
driverlib/legacy/MSP432xx/legacy_gpio.c, with driverlib/gpio.h and
driverlib/legacy/MSP432xx/legacy_gpio.h containing the API declarations for use by
applications.
Thu Jan 21 2016 12:34:41 AM
133
General Purpose Input/Output (GPIO)
10.4.2 Function Documentation
10.4.2.1 void GPIO_clearInterruptFlag ( uint_fast8_t selectedPort, uint_fast16_t
selectedPins )
This function clears the interrupt flag on the selected pin.
This function clears the interrupt flag on the selected pin. Note that only Port 1, 2, A have this
capability.
Parameters
selectedPort
is the selected port. Valid values are:
GPIO_PORT_P1
GPIO_PORT_P2
GPIO_PORT_PA
selectedPins
is the specified pin in the selected port. Mask value is the logical OR of any of the following:
GPIO_PIN0
GPIO_PIN1
GPIO_PIN2
GPIO_PIN3
GPIO_PIN4
GPIO_PIN5
GPIO_PIN6
GPIO_PIN7
GPIO_PIN8
GPIO_PIN9
GPIO_PIN10
GPIO_PIN11
GPIO_PIN12
GPIO_PIN13
GPIO_PIN14
GPIO_PIN15
Modified bits of PxIFG register.
Returns
None
10.4.2.2 void GPIO_disableInterrupt ( uint_fast8_t selectedPort, uint_fast16_t
selectedPins )
This function disables the port interrupt on the selected pin.
Thu Jan 21 2016 12:34:41 AM
134
General Purpose Input/Output (GPIO)
This function disables the port interrupt on the selected pin. Note that only Port 1, 2, A have this
capability.
Thu Jan 21 2016 12:34:41 AM
135
General Purpose Input/Output (GPIO)
Parameters
selectedPort
is the selected port. Valid values are:
GPIO_PORT_P1
GPIO_PORT_P2
GPIO_PORT_PA
selectedPins
is the specified pin in the selected port. Mask value is the logical OR of any of the following:
GPIO_PIN0
GPIO_PIN1
GPIO_PIN2
GPIO_PIN3
GPIO_PIN4
GPIO_PIN5
GPIO_PIN6
GPIO_PIN7
GPIO_PIN8
GPIO_PIN9
GPIO_PIN10
GPIO_PIN11
GPIO_PIN12
GPIO_PIN13
GPIO_PIN14
GPIO_PIN15
Modified bits of PxIE register.
Returns
None
10.4.2.3 void GPIO_enableInterrupt ( uint_fast8_t selectedPort, uint_fast16_t
selectedPins )
This function enables the port interrupt on the selected pin.
This function enables the port interrupt on the selected pin. Note that only Port 1, 2, A have this
capability.
Thu Jan 21 2016 12:34:41 AM
136
General Purpose Input/Output (GPIO)
Parameters
selectedPort
is the selected port. Valid values are:
GPIO_PORT_P1
GPIO_PORT_P2
GPIO_PORT_PA
selectedPins
is the specified pin in the selected port. Mask value is the logical OR of any of the following:
GPIO_PIN0
GPIO_PIN1
GPIO_PIN2
GPIO_PIN3
GPIO_PIN4
GPIO_PIN5
GPIO_PIN6
GPIO_PIN7
GPIO_PIN8
GPIO_PIN9
GPIO_PIN10
GPIO_PIN11
GPIO_PIN12
GPIO_PIN13
GPIO_PIN14
GPIO_PIN15
Modified bits of PxIE register.
Returns
None
10.4.2.4 uint_fast16_t GPIO_getEnabledInterruptStatus ( uint_fast8_t selectedPort )
This function gets the interrupt status of the provided PIN and masks it with the interrupts that are
actually enabled. This is useful for inside ISRs where the status of only the enabled interrupts
needs to be checked.
Thu Jan 21 2016 12:34:41 AM
137
General Purpose Input/Output (GPIO)
Parameters
selectedPort
is the selected port. Valid values are:
GPIO_PORT_P1
GPIO_PORT_P2
GPIO_PORT_P3
GPIO_PORT_P4
GPIO_PORT_P5
GPIO_PORT_P6
GPIO_PORT_P7
GPIO_PORT_P8
GPIO_PORT_P9
GPIO_PORT_P10
GPIO_PORT_P11
GPIO_PORT_PJ
Returns
Logical OR of any of the following:
GPIO_PIN0
GPIO_PIN1
GPIO_PIN2
GPIO_PIN3
GPIO_PIN4
GPIO_PIN5
GPIO_PIN6
GPIO_PIN7
GPIO_PIN8
GPIO_PIN9
GPIO_PIN10
GPIO_PIN11
GPIO_PIN12
GPIO_PIN13
GPIO_PIN14
GPIO_PIN15,
PIN_ALL8,
PIN_ALL16
indicating the interrupt status of the selected pins [Default: 0]
References GPIO_getInterruptStatus().
10.4.2.5 uint8_t GPIO_getInputPinValue ( uint_fast8_t selectedPort, uint_fast16_t
selectedPins )
This function gets the input value on the selected pin.
Thu Jan 21 2016 12:34:41 AM
138
General Purpose Input/Output (GPIO)
This function gets the input value on the selected pin.
Thu Jan 21 2016 12:34:41 AM
139
General Purpose Input/Output (GPIO)
Parameters
selectedPort
is the selected port. Valid values are:
GPIO_PORT_P1
GPIO_PORT_P2
GPIO_PORT_P3
GPIO_PORT_P4
GPIO_PORT_P5
GPIO_PORT_P6
GPIO_PORT_P7
GPIO_PORT_P8
GPIO_PORT_P9
GPIO_PORT_P10
GPIO_PORT_P11
GPIO_PORT_PJ
selectedPins
is the specified pin in the selected port. Valid values are:
GPIO_PIN0
GPIO_PIN1
GPIO_PIN2
GPIO_PIN3
GPIO_PIN4
GPIO_PIN5
GPIO_PIN6
GPIO_PIN7
GPIO_PIN8
GPIO_PIN9
GPIO_PIN10
GPIO_PIN11
GPIO_PIN12
GPIO_PIN13
GPIO_PIN14
GPIO_PIN15
Thu Jan 21 2016 12:34:41 AM
140
General Purpose Input/Output (GPIO)
Returns
One of the following:
GPIO_INPUT_PIN_HIGH
GPIO_INPUT_PIN_LOW
indicating the status of the pin
10.4.2.6 uint_fast16_t GPIO_getInterruptStatus ( uint_fast8_t selectedPort, uint_fast16_t
selectedPins )
This function gets the interrupt status of the selected pin.
This function gets the interrupt status of the selected pin. Note that only Port 1, 2, A have this
capability.
Parameters
selectedPort
is the selected port. Valid values are:
GPIO_PORT_P1
GPIO_PORT_P2
GPIO_PORT_PA
selectedPins
is the specified pin in the selected port. Mask value is the logical OR of any of the following:
GPIO_PIN0
GPIO_PIN1
GPIO_PIN2
GPIO_PIN3
GPIO_PIN4
GPIO_PIN5
GPIO_PIN6
GPIO_PIN7
GPIO_PIN8
GPIO_PIN9
GPIO_PIN10
GPIO_PIN11
GPIO_PIN12
GPIO_PIN13
GPIO_PIN14
GPIO_PIN15
Returns
Logical OR of any of the following:
GPIO_PIN0
GPIO_PIN1
GPIO_PIN2
Thu Jan 21 2016 12:34:41 AM
141
General Purpose Input/Output (GPIO)
GPIO_PIN3
GPIO_PIN4
GPIO_PIN5
GPIO_PIN6
GPIO_PIN7
GPIO_PIN8
GPIO_PIN9
GPIO_PIN10
GPIO_PIN11
GPIO_PIN12
GPIO_PIN13
GPIO_PIN14
GPIO_PIN15
indicating the interrupt status of the selected pins [Default: 0]
Referenced by GPIO_getEnabledInterruptStatus().
10.4.2.7 void GPIO_interruptEdgeSelect ( uint_fast8_t selectedPort, uint_fast16_t
selectedPins, uint_fast8_t edgeSelect )
This function selects on what edge the port interrupt flag should be set for a transition.
This function selects on what edge the port interrupt flag should be set for a transition. Values for
edgeSelect should be GPIO_LOW_TO_HIGH_TRANSITION or
GPIO_HIGH_TO_LOW_TRANSITION.
Parameters
selectedPort
is the selected port. Valid values are:
GPIO_PORT_P1
GPIO_PORT_P2
GPIO_PORT_P3
GPIO_PORT_P4
GPIO_PORT_P5
GPIO_PORT_P6
GPIO_PORT_P7
GPIO_PORT_P8
GPIO_PORT_P9
GPIO_PORT_P10
GPIO_PORT_P11
GPIO_PORT_PJ
Thu Jan 21 2016 12:34:41 AM
142
General Purpose Input/Output (GPIO)
selectedPins
is the specified pin in the selected port. Mask value is the logical OR of any of the following:
GPIO_PIN0
GPIO_PIN1
GPIO_PIN2
GPIO_PIN3
GPIO_PIN4
GPIO_PIN5
GPIO_PIN6
GPIO_PIN7
GPIO_PIN8
GPIO_PIN9
GPIO_PIN10
GPIO_PIN11
GPIO_PIN12
GPIO_PIN13
GPIO_PIN14
GPIO_PIN15
edgeSelect
specifies what transition sets the interrupt flag Valid values are:
GPIO_HIGH_TO_LOW_TRANSITION
GPIO_LOW_TO_HIGH_TRANSITION
Modified bits of PxIES register.
Returns
None
10.4.2.8 void GPIO_registerInterrupt ( uint_fast8_t selectedPort, void(∗)(void) intHandler )
Registers an interrupt handler for the port interrupt.
Parameters
selectedPort
intHandler
is the port to register the interrupt handler
is a pointer to the function to be called when the port interrupt occurs.
This function registers the handler to be called when a port interrupt occurs. This function enables
the global interrupt in the interrupt controller; specific GPIO interrupts must be enabled via
GPIO_enableInterrupt(). It is the interrupt handler’s responsibility to clear the interrupt source via
GPIO_clearInterruptFlag().
Clock System can generate interrupts when
See Also
Interrupt_registerInterrupt() for important information about registering interrupt handlers.
Thu Jan 21 2016 12:34:41 AM
143
General Purpose Input/Output (GPIO)
Returns
None.
References Interrupt_enableInterrupt(), and Interrupt_registerInterrupt().
10.4.2.9 void GPIO_setAsInputPin ( uint_fast8_t selectedPort, uint_fast16_t selectedPins
)
This function configures the selected Pin as input pin.
This function selected pins on a selected port as input pins.
Thu Jan 21 2016 12:34:41 AM
144
General Purpose Input/Output (GPIO)
Parameters
selectedPort
is the selected port. Valid values are:
GPIO_PORT_P1
GPIO_PORT_P2
GPIO_PORT_P3
GPIO_PORT_P4
GPIO_PORT_P5
GPIO_PORT_P6
GPIO_PORT_P7
GPIO_PORT_P8
GPIO_PORT_P9
GPIO_PORT_P10
GPIO_PORT_P11
GPIO_PORT_PJ
selectedPins
is the specified pin in the selected port. Mask value is the logical OR of any of the following:
GPIO_PIN0
GPIO_PIN1
GPIO_PIN2
GPIO_PIN3
GPIO_PIN4
GPIO_PIN5
GPIO_PIN6
GPIO_PIN7
GPIO_PIN8
GPIO_PIN9
GPIO_PIN10
GPIO_PIN11
GPIO_PIN12
GPIO_PIN13
GPIO_PIN14
GPIO_PIN15
Modified bits of PxDIR register, bits of PxREN register and bits of PxSEL register.
Thu Jan 21 2016 12:34:41 AM
145
General Purpose Input/Output (GPIO)
Returns
None
10.4.2.10 void GPIO_setAsInputPinWithPullDownResistor ( uint_fast8_t selectedPort,
uint_fast16_t selectedPins )
This function sets the selected Pin in input Mode with Pull Down resistor.
This function sets the selected Pin in input Mode with Pull Down resistor.
Parameters
selectedPort
is the selected port. Valid values are:
GPIO_PORT_P1
GPIO_PORT_P2
GPIO_PORT_P3
GPIO_PORT_P4
GPIO_PORT_P5
GPIO_PORT_P6
GPIO_PORT_P7
GPIO_PORT_P8
GPIO_PORT_P9
GPIO_PORT_P10
GPIO_PORT_P11
GPIO_PORT_PJ
Thu Jan 21 2016 12:34:41 AM
146
General Purpose Input/Output (GPIO)
selectedPins
is the specified pin in the selected port. Mask value is the logical OR of any of the following:
GPIO_PIN0
GPIO_PIN1
GPIO_PIN2
GPIO_PIN3
GPIO_PIN4
GPIO_PIN5
GPIO_PIN6
GPIO_PIN7
GPIO_PIN8
GPIO_PIN9
GPIO_PIN10
GPIO_PIN11
GPIO_PIN12
GPIO_PIN13
GPIO_PIN14
GPIO_PIN15
Modified bits of PxDIR register, bits of PxOUT register and bits of PxREN register.
Returns
None
10.4.2.11 void GPIO_setAsInputPinWithPullUpResistor ( uint_fast8_t selectedPort,
uint_fast16_t selectedPins )
This function sets the selected Pin in input Mode with Pull Up resistor.
This function sets the selected Pin in input Mode with Pull Up resistor.
Thu Jan 21 2016 12:34:41 AM
147
General Purpose Input/Output (GPIO)
Parameters
selectedPort
is the selected port. Valid values are:
GPIO_PORT_P1
GPIO_PORT_P2
GPIO_PORT_P3
GPIO_PORT_P4
GPIO_PORT_P5
GPIO_PORT_P6
GPIO_PORT_P7
GPIO_PORT_P8
GPIO_PORT_P9
GPIO_PORT_P10
GPIO_PORT_P11
GPIO_PORT_PJ
selectedPins
is the specified pin in the selected port. Mask value is the logical OR of any of the following:
GPIO_PIN0
GPIO_PIN1
GPIO_PIN2
GPIO_PIN3
GPIO_PIN4
GPIO_PIN5
GPIO_PIN6
GPIO_PIN7
GPIO_PIN8
GPIO_PIN9
GPIO_PIN10
GPIO_PIN11
GPIO_PIN12
GPIO_PIN13
GPIO_PIN14
GPIO_PIN15
Thu Jan 21 2016 12:34:41 AM
148
General Purpose Input/Output (GPIO)
Modified bits of PxDIR register, bits of PxOUT register and bits of PxREN register.
Returns
None
10.4.2.12 void GPIO_setAsOutputPin ( uint_fast8_t selectedPort, uint_fast16_t
selectedPins )
This function configures the selected Pin as output pin.
This function selected pins on a selected port as output pins.
Parameters
selectedPort
is the selected port. Valid values are:
GPIO_PORT_P1
GPIO_PORT_P2
GPIO_PORT_P3
GPIO_PORT_P4
GPIO_PORT_P5
GPIO_PORT_P6
GPIO_PORT_P7
GPIO_PORT_P8
GPIO_PORT_P9
GPIO_PORT_P10
GPIO_PORT_P11
GPIO_PORT_PJ
Thu Jan 21 2016 12:34:41 AM
149
General Purpose Input/Output (GPIO)
selectedPins
is the specified pin in the selected port. Mask value is the logical OR of any of the following:
GPIO_PIN0
GPIO_PIN1
GPIO_PIN2
GPIO_PIN3
GPIO_PIN4
GPIO_PIN5
GPIO_PIN6
GPIO_PIN7
GPIO_PIN8
GPIO_PIN9
GPIO_PIN10
GPIO_PIN11
GPIO_PIN12
GPIO_PIN13
GPIO_PIN14
GPIO_PIN15
Modified bits of PxDIR register and bits of PxSEL register.
Returns
None
10.4.2.13 void GPIO_setAsPeripheralModuleFunctionInputPin ( uint_fast8_t selectedPort,
uint_fast16_t selectedPins, uint_fast8_t mode )
This function configures the peripheral module function in the input direction for the selected pin
for either primary, secondary or ternary module function modes.
This function configures the peripheral module function in the input direction for the selected pin
for either primary, secondary or ternary module function modes. Accepted values for mode are
GPIO_PRIMARY_MODULE_FUNCTION, GPIO_SECONDARY_MODULE_FUNCTION, and
GPIO_TERTIARY_MODULE_FUNCTION
Thu Jan 21 2016 12:34:41 AM
150
General Purpose Input/Output (GPIO)
Parameters
selectedPort
is the selected port. Valid values are:
GPIO_PORT_P1
GPIO_PORT_P2
GPIO_PORT_P3
GPIO_PORT_P4
GPIO_PORT_P5
GPIO_PORT_P6
GPIO_PORT_P7
GPIO_PORT_P8
GPIO_PORT_P9
GPIO_PORT_P10
GPIO_PORT_P11
GPIO_PORT_PJ
selectedPins
is the specified pin in the selected port. Mask value is the logical OR of any of the following:
GPIO_PIN0
GPIO_PIN1
GPIO_PIN2
GPIO_PIN3
GPIO_PIN4
GPIO_PIN5
GPIO_PIN6
GPIO_PIN7
GPIO_PIN8
GPIO_PIN9
GPIO_PIN10
GPIO_PIN11
GPIO_PIN12
GPIO_PIN13
GPIO_PIN14
GPIO_PIN15
Thu Jan 21 2016 12:34:41 AM
151
General Purpose Input/Output (GPIO)
mode
is the specified mode that the pin should be configured for the module function. Valid
values are:
GPIO_PRIMARY_MODULE_FUNCTION
GPIO_SECONDARY_MODULE_FUNCTION
GPIO_TERTIARY_MODULE_FUNCTION
Modified bits of PxDIR register and bits of PxSEL register.
Returns
None
10.4.2.14 void GPIO_setAsPeripheralModuleFunctionOutputPin ( uint_fast8_t selectedPort,
uint_fast16_t selectedPins, uint_fast8_t mode )
This function configures the peripheral module function in the output direction for the selected pin
for either primary, secondary or ternary module function modes.
This function configures the peripheral module function in the output direction for the selected pin
for either primary, secondary or ternary module function modes. Accepted values for mode are
GPIO_PRIMARY_MODULE_FUNCTION, GPIO_SECONDARY_MODULE_FUNCTION, and
GPIO_TERTIARY_MODULE_FUNCTION
Parameters
selectedPort
is the selected port. Valid values are:
GPIO_PORT_P1
GPIO_PORT_P2
GPIO_PORT_P3
GPIO_PORT_P4
GPIO_PORT_P5
GPIO_PORT_P6
GPIO_PORT_P7
GPIO_PORT_P8
GPIO_PORT_P9
GPIO_PORT_P10
GPIO_PORT_P11
GPIO_PORT_PJ
Thu Jan 21 2016 12:34:41 AM
152
General Purpose Input/Output (GPIO)
selectedPins
is the specified pin in the selected port. Mask value is the logical OR of any of the following:
GPIO_PIN0
GPIO_PIN1
GPIO_PIN2
GPIO_PIN3
GPIO_PIN4
GPIO_PIN5
GPIO_PIN6
GPIO_PIN7
GPIO_PIN8
GPIO_PIN9
GPIO_PIN10
GPIO_PIN11
GPIO_PIN12
GPIO_PIN13
GPIO_PIN14
GPIO_PIN15
Thu Jan 21 2016 12:34:41 AM
153
General Purpose Input/Output (GPIO)
mode
is the specified mode that the pin should be configured for the module function. Valid
values are:
GPIO_PRIMARY_MODULE_FUNCTION
GPIO_SECONDARY_MODULE_FUNCTION
GPIO_TERTIARY_MODULE_FUNCTION
Modified bits of PxDIR register and bits of PxSEL register.
Returns
None
10.4.2.15 void GPIO_setDriveStrengthHigh ( uint_fast8_t selectedPort, uint_fast8_t
selectedPins )
This function sets the drive strength to high for the selected port
Parameters
selectedPort
is the selected port. Valid values are:
GPIO_PORT_P1,
GPIO_PORT_P2,
GPIO_PORT_P3,
GPIO_PORT_P4,
GPIO_PORT_P5,
GPIO_PORT_P6,
GPIO_PORT_P7,
GPIO_PORT_P8,
GPIO_PORT_P9,
GPIO_PORT_P10,
GPIO_PORT_PJ
Thu Jan 21 2016 12:34:41 AM
154
General Purpose Input/Output (GPIO)
selectedPins
is the specified pin in the selected port. Valid values are:
GPIO_PIN0,
GPIO_PIN1,
GPIO_PIN2,
GPIO_PIN3,
GPIO_PIN4,
GPIO_PIN5,
GPIO_PIN6,
GPIO_PIN7,
GPIO_PIN8,
PIN_ALL8,
Returns
None
10.4.2.16 void GPIO_setDriveStrengthLow ( uint_fast8_t selectedPort, uint_fast8_t
selectedPins )
This function sets the drive strength to low for the selected port
Parameters
selectedPort
is the selected port. Valid values are:
GPIO_PORT_P1,
GPIO_PORT_P2,
GPIO_PORT_P3,
GPIO_PORT_P4,
GPIO_PORT_P5,
GPIO_PORT_P6,
GPIO_PORT_P7,
GPIO_PORT_P8,
GPIO_PORT_P9,
GPIO_PORT_P10,
GPIO_PORT_PJ
Thu Jan 21 2016 12:34:41 AM
155
General Purpose Input/Output (GPIO)
selectedPins
is the specified pin in the selected port. Valid values are:
GPIO_PIN0,
GPIO_PIN1,
GPIO_PIN2,
GPIO_PIN3,
GPIO_PIN4,
GPIO_PIN5,
GPIO_PIN6,
GPIO_PIN7,
GPIO_PIN8,
PIN_ALL8,
Returns
None
10.4.2.17 void GPIO_setOutputHighOnPin ( uint_fast8_t selectedPort, uint_fast16_t
selectedPins )
This function sets output HIGH on the selected Pin.
This function sets output HIGH on the selected port’s pin.
Parameters
selectedPort
is the selected port. Valid values are:
GPIO_PORT_P1
GPIO_PORT_P2
GPIO_PORT_P3
GPIO_PORT_P4
GPIO_PORT_P5
GPIO_PORT_P6
GPIO_PORT_P7
GPIO_PORT_P8
GPIO_PORT_P9
GPIO_PORT_P10
GPIO_PORT_P11
GPIO_PORT_PJ
Thu Jan 21 2016 12:34:41 AM
156
General Purpose Input/Output (GPIO)
selectedPins
is the specified pin in the selected port. Mask value is the logical OR of any of the following:
GPIO_PIN0
GPIO_PIN1
GPIO_PIN2
GPIO_PIN3
GPIO_PIN4
GPIO_PIN5
GPIO_PIN6
GPIO_PIN7
GPIO_PIN8
GPIO_PIN9
GPIO_PIN10
GPIO_PIN11
GPIO_PIN12
GPIO_PIN13
GPIO_PIN14
GPIO_PIN15
Modified bits of PxOUT register.
Returns
None
10.4.2.18 void GPIO_setOutputLowOnPin ( uint_fast8_t selectedPort, uint_fast16_t
selectedPins )
This function sets output LOW on the selected Pin.
This function sets output LOW on the selected port’s pin.
Thu Jan 21 2016 12:34:41 AM
157
General Purpose Input/Output (GPIO)
Parameters
selectedPort
is the selected port. Valid values are:
GPIO_PORT_P1
GPIO_PORT_P2
GPIO_PORT_P3
GPIO_PORT_P4
GPIO_PORT_P5
GPIO_PORT_P6
GPIO_PORT_P7
GPIO_PORT_P8
GPIO_PORT_P9
GPIO_PORT_P10
GPIO_PORT_P11
GPIO_PORT_PJ
selectedPins
is the specified pin in the selected port. Mask value is the logical OR of any of the following:
GPIO_PIN0
GPIO_PIN1
GPIO_PIN2
GPIO_PIN3
GPIO_PIN4
GPIO_PIN5
GPIO_PIN6
GPIO_PIN7
GPIO_PIN8
GPIO_PIN9
GPIO_PIN10
GPIO_PIN11
GPIO_PIN12
GPIO_PIN13
GPIO_PIN14
GPIO_PIN15
Thu Jan 21 2016 12:34:41 AM
158
General Purpose Input/Output (GPIO)
Returns
None
10.4.2.19 void GPIO_toggleOutputOnPin ( uint_fast8_t selectedPort, uint_fast16_t
selectedPins )
This function toggles the output on the selected Pin.
This function toggles the output on the selected port’s pin.
Parameters
selectedPort
is the selected port. Valid values are:
GPIO_PORT_P1
GPIO_PORT_P2
GPIO_PORT_P3
GPIO_PORT_P4
GPIO_PORT_P5
GPIO_PORT_P6
GPIO_PORT_P7
GPIO_PORT_P8
GPIO_PORT_P9
GPIO_PORT_P10
GPIO_PORT_P11
GPIO_PORT_PJ
Thu Jan 21 2016 12:34:41 AM
159
General Purpose Input/Output (GPIO)
selectedPins
is the specified pin in the selected port. Mask value is the logical OR of any of the following:
GPIO_PIN0
GPIO_PIN1
GPIO_PIN2
GPIO_PIN3
GPIO_PIN4
GPIO_PIN5
GPIO_PIN6
GPIO_PIN7
GPIO_PIN8
GPIO_PIN9
GPIO_PIN10
GPIO_PIN11
GPIO_PIN12
GPIO_PIN13
GPIO_PIN14
GPIO_PIN15
Modified bits of PxOUT register.
Returns
None
10.4.2.20 void GPIO_unregisterInterrupt ( uint_fast8_t selectedPort )
Unregisters the interrupt handler for the port.
Parameters
selectedPort
is the port to unregister the interrupt handler
This function unregisters the handler to be called when a port interrupt occurs. This function also
masks off the interrupt in the interrupt controller so that the interrupt handler no longer is called.
See Also
Interrupt_registerInterrupt() for important information about registering interrupt handlers.
Returns
None.
References Interrupt_disableInterrupt(), and Interrupt_unregisterInterrupt().
Thu Jan 21 2016 12:34:41 AM
160
Inter-Integrated Circuit (I2C)
11
Inter-Integrated Circuit (I2C)
Module Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .162
Master Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 162
Slave Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 163
Timeout Parameter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 164
Programming Example . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .164
Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 165
11.1
I2C Module Operation
In I2C mode, the eUSCI_B module provides an interface between the device and I2C-compatible
devices connected by the two-wire I2C serial bus. External components attached to the I2C bus
serially transmit and/or receive serial data to/from the eUSCI_B module through the 2-wire I2C
interface. The Inter-Integrated Circuit (I2C) API provides a set of functions for using the MSPWare
I2C modules. Functions are provided to initialize the I2C modules, to send and receive data,
obtain status, and to manage interrupts for the I2C modules. For the sake of simplicity and code
readability, the EUSCI_B module name has been omitted from the API name space.
The I2C module provide the ability to communicate to other IC devices over an I2C bus. The I2C
bus is specified to support devices that can both transmit and receive (write and read) data. Also,
devices on the I2C bus can be designated as either a master or a slave. The MSPWare L I2C
modules support both sending and receiving data as either a master or a slave, and also support
the simultaneous operation as both a master and a slave.
I2C module can generate interrupts. The I2C module configured as a master will generate
interrupts when a transmit or receive operation is completed (or aborted due to an error). The I2C
module configured as a slave will generate interrupts when data has been sent or requested by a
master.
11.2
Master Operation
To drive the master module, the APIs need to be invoked in the following order
I2C_initMaster
I2C_setSlaveAddress
I2C_setMode
I2C_enableModule
I2C_enableInterrupt ( if interrupts are being used ) This may be followed by the APIs for
transmit or receive as required
The user must first initialize the I2C module and configure it as a master with a call to
I2C_initMaster . That function will set the clock and data rates. This is followed by a call to set the
slave address with which the master intends to communicate with using I2C_setSlaveAddress .
Then the mode of operation (transmit or receive) is chosen using I2C_setMode . The I2C module
may now be enabled using I2C_enableModule . It is recommended to enable the I2C module
before enabling the interrupts. Any transmission or reception of data may be initiated at this point
after interrupts are enabled (if any).
Thu Jan 21 2016 12:34:41 AM
161
Inter-Integrated Circuit (I2C)
The transaction can then be initiated on the bus by calling the transmit or receive related APIs as
listed below.
Master Single Byte Transmission
I2C_masterSendSingleByte
Master Multiple Byte Transmission
I2C_masterSendMultiByteStart
I2C_masterSendMultiByteNext
I2C_masterSendMultiByteStop
Master Single Byte Reception
I2C_masterReceiveSingleByte
Master Multiple Byte Reception
I2C_masterReceiveStart
I2C_masterReceiveMultiByteNext
I2C_masterReceiveMultiByteFinish
I2C_masterReceiveMultiByteStop
For the interrupt-driven transaction, the user must register an interrupt handler for the I2C devices
and enable the I2C interrupt.
11.3
Slave Operation
To drive the slave module, the APIs need to be invoked in the following order
I2C_initSlave
I2C_setMode
I2C_enableModule
I2C_enableInterrupt ( if interrupts are being used )
The user must first call the I2C_initSlave to initialize the slave module in I2C mode and set the
slave address. This is followed by a call to set the mode of operation (transmit or receive). The I2C
module may now be enabled using I2C_enableModule . It is recommended to enable the I2C
module before enabling the interrupts. Any transmission or reception of data may be initiated at
this point after interrupts are enabled (if any).
The transaction can then be initiated on the bus by calling the transmit or receive related APIs as
listed below.
Slave Transmission API
I2C_slavePutData
Slave Reception API
I2C_slaveGetData
Thu Jan 21 2016 12:34:41 AM
162
Inter-Integrated Circuit (I2C)
For the interrupt-driven transaction, the user must register an interrupt handler for the I2C devices
and enable the I2C interrupt.
11.4
Timeout Parameters
For serial transmission APIs (sending/receiving), a "timeout" API exists that will return control of
execution back to the user application if a specified duration passes. The variable that is passed
into these functions is a unit of time specified by how many "loop iterations" elapse before
unsuccessful transmission of data.
11.5
Programming Example
The DriverLib package contains a variety of different code examples that demonstrate the usage
of the I2C module. These code examples are accessible under the examples/ folder of the
MSPWare release as well as through TI Resource Explorer if using Code Composer Studio.
These code examples provide a comprehensive list of use cases as well as practical applications
involving each module.
Below is a simple example of how to setup the I2C module for master operation with a 400KHz
clock.
First, below is an example of setting up the I2C module configuration structure:
/* I2C Master Configuration Parameter */
const eUSCI_I2C_MasterConfig i2cConfig =
{
EUSCI_B_I2C_CLOCKSOURCE_SMCLK,
3000000,
EUSCI_B_I2C_SET_DATA_RATE_400KBPS,
0,
EUSCI_B_I2C_NO_AUTO_STOP
};
// SMCLK Clock Source
// SMCLK = 3MHz
// Desired I2C Clock of 400khz
// No byte counter threshold
// No Autostop
Below are the actual DriverLib calls to configure/setup the I2C module:
/* Initializing I2C Master to SMCLK at 400kbs with no autostop */
MAP_I2C_initMaster(EUSCI_B0_BASE, &i2cConfig);
/* Specify slave address */
MAP_I2C_setSlaveAddress(EUSCI_B0_BASE,
SLAVE_ADDRESS);
/* Set Master in transmit mode */
MAP_I2C_setMode(EUSCI_B0_BASE, EUSCI_B_I2C_TRANSMIT_MODE);
/* Enable I2C Module to start operations */
MAP_I2C_enableModule(EUSCI_B0_BASE);
/* Enable and clear the interrupt flag */
MAP_I2C_clearInterruptFlag(EUSCI_B0_BASE,
EUSCI_B_I2C_TRANSMIT_INTERRUPT0 + EUSCI_B_I2C_NAK_INTERRUPT);
/* Enable master transmit interrupt */
MAP_I2C_enableInterrupt(EUSCI_B0_BASE,
EUSCI_B_I2C_TRANSMIT_INTERRUPT0 + EUSCI_B_I2C_NAK_INTERRUPT);
MAP_Interrupt_enableInterrupt(INT_EUSCIB0);
Thu Jan 21 2016 12:34:41 AM
163
Inter-Integrated Circuit (I2C)
11.6
Definitions
Data Structures
struct _eUSCI_I2C_MasterConfig
Functions
void I2C_clearInterruptFlag (uint32_t moduleInstance, uint_fast16_t mask)
void I2C_disableInterrupt (uint32_t moduleInstance, uint_fast16_t mask)
void I2C_disableModule (uint32_t moduleInstance)
void I2C_disableMultiMasterMode (uint32_t moduleInstance)
void I2C_enableInterrupt (uint32_t moduleInstance, uint_fast16_t mask)
void I2C_enableModule (uint32_t moduleInstance)
void I2C_enableMultiMasterMode (uint32_t moduleInstance)
uint_fast16_t I2C_getEnabledInterruptStatus (uint32_t moduleInstance)
uint_fast16_t I2C_getInterruptStatus (uint32_t moduleInstance, uint16_t mask)
uint_fast8_t I2C_getMode (uint32_t moduleInstance)
uint32_t I2C_getReceiveBufferAddressForDMA (uint32_t moduleInstance)
uint32_t I2C_getTransmitBufferAddressForDMA (uint32_t moduleInstance)
void I2C_initMaster (uint32_t moduleInstance, const eUSCI_I2C_MasterConfig ∗config)
void I2C_initSlave (uint32_t moduleInstance, uint_fast16_t slaveAddress, uint_fast8_t
slaveAddressOffset, uint32_t slaveOwnAddressEnable)
uint8_t I2C_isBusBusy (uint32_t moduleInstance)
bool I2C_masterIsStartSent (uint32_t moduleInstance)
uint8_t I2C_masterIsStopSent (uint32_t moduleInstance)
uint8_t I2C_masterReceiveMultiByteFinish (uint32_t moduleInstance)
bool I2C_masterReceiveMultiByteFinishWithTimeout (uint32_t moduleInstance, uint8_t
∗txData, uint32_t timeout)
uint8_t I2C_masterReceiveMultiByteNext (uint32_t moduleInstance)
void I2C_masterReceiveMultiByteStop (uint32_t moduleInstance)
uint8_t I2C_masterReceiveSingle (uint32_t moduleInstance)
uint8_t I2C_masterReceiveSingleByte (uint32_t moduleInstance)
void I2C_masterReceiveStart (uint32_t moduleInstance)
void I2C_masterSendMultiByteFinish (uint32_t moduleInstance, uint8_t txData)
bool I2C_masterSendMultiByteFinishWithTimeout (uint32_t moduleInstance, uint8_t txData,
uint32_t timeout)
void I2C_masterSendMultiByteNext (uint32_t moduleInstance, uint8_t txData)
bool I2C_masterSendMultiByteNextWithTimeout (uint32_t moduleInstance, uint8_t txData,
uint32_t timeout)
void I2C_masterSendMultiByteStart (uint32_t moduleInstance, uint8_t txData)
bool I2C_masterSendMultiByteStartWithTimeout (uint32_t moduleInstance, uint8_t txData,
uint32_t timeout)
void I2C_masterSendMultiByteStop (uint32_t moduleInstance)
bool I2C_masterSendMultiByteStopWithTimeout (uint32_t moduleInstance, uint32_t timeout)
void I2C_masterSendSingleByte (uint32_t moduleInstance, uint8_t txData)
bool I2C_masterSendSingleByteWithTimeout (uint32_t moduleInstance, uint8_t txData,
uint32_t timeout)
void I2C_masterSendStart (uint32_t moduleInstance)
void I2C_registerInterrupt (uint32_t moduleInstance, void(∗intHandler)(void))
void I2C_setMode (uint32_t moduleInstance, uint_fast8_t mode)
void I2C_setSlaveAddress (uint32_t moduleInstance, uint_fast16_t slaveAddress)
uint8_t I2C_slaveGetData (uint32_t moduleInstance)
void I2C_slavePutData (uint32_t moduleInstance, uint8_t transmitData)
void I2C_slaveSendNAK (uint32_t moduleInstance)
void I2C_unregisterInterrupt (uint32_t moduleInstance)
Thu Jan 21 2016 12:34:41 AM
164
Inter-Integrated Circuit (I2C)
11.6.1 Detailed Description
The code for this module is contained in driverlib/i2c.c, with driverlib/i2c.h containing
the API declarations for use by applications.
Thu Jan 21 2016 12:34:41 AM
165
Inter-Integrated Circuit (I2C)
11.6.2 Function Documentation
11.6.2.1 void I2C_clearInterruptFlag ( uint32_t moduleInstance, uint_fast16_t mask )
Clears I2C interrupt sources.
Parameters
moduleInstance
is the instance of the eUSCI B (I2C) module. Valid parameters vary from part to part, but
can include:
EUSCI_B0_BASE
EUSCI_B1_BASE
EUSCI_B2_BASE
EUSCI_B3_BASE
It is important to note that for eUSCI modules, only "B" modules such as EUSCI_B0
can be used. "A" modules such as EUSCI_A0 do not support the I2C mode.
mask
is a bit mask of the interrupt sources to be cleared.
The I2C interrupt source is cleared, so that it no longer asserts. The highest interrupt flag is
automatically cleared when an interrupt vector generator is used.
The mask parameter has the same definition as the mask parameter to I2C_enableInterrupt().
Modified register is UCBxIFG.
Returns
None.
11.6.2.2 void I2C_disableInterrupt ( uint32_t moduleInstance, uint_fast16_t mask )
Disables individual I2C interrupt sources.
Parameters
moduleInstance
is the instance of the eUSCI B (I2C) module. Valid parameters vary from part to part, but
can include:
EUSCI_B0_BASE
EUSCI_B1_BASE
EUSCI_B2_BASE
EUSCI_B3_BASE
It is important to note that for eUSCI modules, only "B" modules such as EUSCI_B0
can be used. "A" modules such as EUSCI_A0 do not support the I2C mode.
Thu Jan 21 2016 12:34:41 AM
166
Inter-Integrated Circuit (I2C)
mask
is the bit mask of the interrupt sources to be disabled.
Disables the indicated I2C interrupt sources. Only the sources that are enabled can be reflected to
the processor interrupt; disabled sources have no effect on the processor.
The mask parameter is the logical OR of any of the following:
EUSCI_B_I2C_STOP_INTERRUPT - STOP condition interrupt
EUSCI_B_I2C_START_INTERRUPT - START condition interrupt
EUSCI_B_I2C_TRANSMIT_INTERRUPT0 - Transmit interrupt0
EUSCI_B_I2C_TRANSMIT_INTERRUPT1 - Transmit interrupt1
EUSCI_B_I2C_TRANSMIT_INTERRUPT2 - Transmit interrupt2
EUSCI_B_I2C_TRANSMIT_INTERRUPT3 - Transmit interrupt3
EUSCI_B_I2C_RECEIVE_INTERRUPT0 - Receive interrupt0
EUSCI_B_I2C_RECEIVE_INTERRUPT1 - Receive interrupt1
EUSCI_B_I2C_RECEIVE_INTERRUPT2 - Receive interrupt2
EUSCI_B_I2C_RECEIVE_INTERRUPT3 - Receive interrupt3
EUSCI_B_I2C_NAK_INTERRUPT - Not-acknowledge interrupt
EUSCI_B_I2C_ARBITRATIONLOST_INTERRUPT - Arbitration lost interrupt
EUSCI_B_I2C_BIT9_POSITION_INTERRUPT - Bit position 9 interrupt enable
EUSCI_B_I2C_CLOCK_LOW_TIMEOUT_INTERRUPT - Clock low timeout interrupt enable
EUSCI_B_I2C_BYTE_COUNTER_INTERRUPT - Byte counter interrupt enable
Modified register is UCBxIE.
Returns
None.
11.6.2.3 void I2C_disableModule ( uint32_t moduleInstance )
Disables the I2C block.
Parameters
moduleInstance
is the instance of the eUSCI B (I2C) module. Valid parameters vary from part to part, but
can include:
EUSCI_B0_BASE
EUSCI_B1_BASE
EUSCI_B2_BASE
EUSCI_B3_BASE
It is important to note that for eUSCI modules, only "B" modules such as EUSCI_B0
can be used. "A" modules such as EUSCI_A0 do not support the I2C mode.
This will disable operation of the I2C block. Modified bits are UCSWRST of UCBxCTL1 register.
Returns
None.
Thu Jan 21 2016 12:34:41 AM
167
Inter-Integrated Circuit (I2C)
11.6.2.4 void I2C_disableMultiMasterMode ( uint32_t moduleInstance )
Disables Multi Master Mode
Thu Jan 21 2016 12:34:41 AM
168
Inter-Integrated Circuit (I2C)
Parameters
moduleInstance
is the instance of the eUSCI B (I2C) module. Valid parameters vary from part to part, but
can include:
EUSCI_B0_BASE
EUSCI_B1_BASE
EUSCI_B2_BASE
EUSCI_B3_BASE
It is important to note that for eUSCI modules, only "B" modules such as EUSCI_B0
can be used. "A" modules such as EUSCI_A0 do not support the I2C mode.
At the end of this function, the I2C module is still disabled till I2C_enableModule is invoked
Modified bits are UCSWRST of OFS_UCBxCTLW0, UCMM bit of UCBxCTLW0
Returns
None.
11.6.2.5 void I2C_enableInterrupt ( uint32_t moduleInstance, uint_fast16_t mask )
Enables individual I2C interrupt sources.
Parameters
moduleInstance
is the instance of the eUSCI B (I2C) module. Valid parameters vary from part to part, but
can include:
EUSCI_B0_BASE
EUSCI_B1_BASE
EUSCI_B2_BASE
EUSCI_B3_BASE
It is important to note that for eUSCI modules, only "B" modules such as EUSCI_B0
can be used. "A" modules such as EUSCI_A0 do not support the I2C mode.
mask
is the bit mask of the interrupt sources to be enabled.
Enables the indicated I2C interrupt sources. Only the sources that are enabled can be reflected to
the processor interrupt; disabled sources have no effect on the processor.
The mask parameter is the logical OR of any of the following:
EUSCI_B_I2C_STOP_INTERRUPT - STOP condition interrupt
EUSCI_B_I2C_START_INTERRUPT - START condition interrupt
EUSCI_B_I2C_TRANSMIT_INTERRUPT0 - Transmit interrupt0
EUSCI_B_I2C_TRANSMIT_INTERRUPT1 - Transmit interrupt1
EUSCI_B_I2C_TRANSMIT_INTERRUPT2 - Transmit interrupt2
EUSCI_B_I2C_TRANSMIT_INTERRUPT3 - Transmit interrupt3
EUSCI_B_I2C_RECEIVE_INTERRUPT0 - Receive interrupt0
EUSCI_B_I2C_RECEIVE_INTERRUPT1 - Receive interrupt1
Thu Jan 21 2016 12:34:41 AM
169
Inter-Integrated Circuit (I2C)
EUSCI_B_I2C_RECEIVE_INTERRUPT2 - Receive interrupt2
EUSCI_B_I2C_RECEIVE_INTERRUPT3 - Receive interrupt3
EUSCI_B_I2C_NAK_INTERRUPT - Not-acknowledge interrupt
EUSCI_B_I2C_ARBITRATIONLOST_INTERRUPT - Arbitration lost interrupt
EUSCI_B_I2C_BIT9_POSITION_INTERRUPT - Bit position 9 interrupt enable
EUSCI_B_I2C_CLOCK_LOW_TIMEOUT_INTERRUPT - Clock low timeout interrupt enable
EUSCI_B_I2C_BYTE_COUNTER_INTERRUPT - Byte counter interrupt enable
Modified registers are UCBxIFG and OFS_UCBxIE.
Returns
None.
11.6.2.6 void I2C_enableModule ( uint32_t moduleInstance )
Enables the I2C block.
Parameters
moduleInstance
is the instance of the eUSCI B (I2C) module. Valid parameters vary from part to part, but
can include:
EUSCI_B0_BASE
EUSCI_B1_BASE
EUSCI_B2_BASE
EUSCI_B3_BASE
It is important to note that for eUSCI modules, only "B" modules such as EUSCI_B0
can be used. "A" modules such as EUSCI_A0 do not support the I2C mode.
This will enable operation of the I2C block. Modified bits are UCSWRST of UCBxCTL1 register.
Returns
None.
11.6.2.7 void I2C_enableMultiMasterMode ( uint32_t moduleInstance )
Enables Multi Master Mode
Parameters
moduleInstance
is the instance of the eUSCI B (I2C) module. Valid parameters vary from part to part, but
can include:
EUSCI_B0_BASE
EUSCI_B1_BASE
EUSCI_B2_BASE
EUSCI_B3_BASE
It is important to note that for eUSCI modules, only "B" modules such as EUSCI_B0
can be used. "A" modules such as EUSCI_A0 do not support the I2C mode.
Thu Jan 21 2016 12:34:41 AM
170
Inter-Integrated Circuit (I2C)
At the end of this function, the I2C module is still disabled till I2C_enableModule is invoked
Modified bits are UCSWRST of OFS_UCBxCTLW0, UCMM bit of UCBxCTLW0
Returns
None.
11.6.2.8 uint_fast16_t I2C_getEnabledInterruptStatus ( uint32_t moduleInstance )
Gets the current I2C interrupt status masked with the enabled interrupts. This function is useful to
call in ISRs to get a list of pending interrupts that are actually enabled and could have caused the
ISR.
Parameters
moduleInstance
is the instance of the eUSCI B (I2C) module. Valid parameters vary from part to part, but
can include:
EUSCI_B0_BASE
EUSCI_B1_BASE
EUSCI_B2_BASE
EUSCI_B3_BASE
It is important to note that for eUSCI modules, only "B" modules such as EUSCI_B0
can be used. "A" modules such as EUSCI_A0 do not support the I2C mode.
Returns
the masked status of the interrupt flag
EUSCI_B_I2C_STOP_INTERRUPT - STOP condition interrupt
EUSCI_B_I2C_START_INTERRUPT - START condition interrupt
EUSCI_B_I2C_TRANSMIT_INTERRUPT0 - Transmit interrupt0
EUSCI_B_I2C_TRANSMIT_INTERRUPT1 - Transmit interrupt1
EUSCI_B_I2C_TRANSMIT_INTERRUPT2 - Transmit interrupt2
EUSCI_B_I2C_TRANSMIT_INTERRUPT3 - Transmit interrupt3
EUSCI_B_I2C_RECEIVE_INTERRUPT0 - Receive interrupt0
EUSCI_B_I2C_RECEIVE_INTERRUPT1 - Receive interrupt1
EUSCI_B_I2C_RECEIVE_INTERRUPT2 - Receive interrupt2
EUSCI_B_I2C_RECEIVE_INTERRUPT3 - Receive interrupt3
EUSCI_B_I2C_NAK_INTERRUPT - Not-acknowledge interrupt
EUSCI_B_I2C_ARBITRATIONLOST_INTERRUPT - Arbitration lost interrupt
EUSCI_B_I2C_BIT9_POSITION_INTERRUPT - Bit position 9 interrupt enable
EUSCI_B_I2C_CLOCK_LOW_TIMEOUT_INTERRUPT - Clock low timeout interrupt
enable
EUSCI_B_I2C_BYTE_COUNTER_INTERRUPT - Byte counter interrupt enable
References I2C_getInterruptStatus().
11.6.2.9 uint_fast16_t I2C_getInterruptStatus ( uint32_t moduleInstance, uint16_t mask )
Gets the current I2C interrupt status.
Thu Jan 21 2016 12:34:41 AM
171
Inter-Integrated Circuit (I2C)
Parameters
moduleInstance
is the instance of the eUSCI B (I2C) module. Valid parameters vary from part to part, but
can include:
EUSCI_B0_BASE
EUSCI_B1_BASE
EUSCI_B2_BASE
EUSCI_B3_BASE
It is important to note that for eUSCI modules, only "B" modules such as EUSCI_B0
can be used. "A" modules such as EUSCI_A0 do not support the I2C mode.
mask
is the masked interrupt flag status to be returned. Mask value is the logical OR of any of
the following:
EUSCI_B_I2C_NAK_INTERRUPT - Not-acknowledge interrupt
EUSCI_B_I2C_ARBITRATIONLOST_INTERRUPT - Arbitration lost interrupt
EUSCI_B_I2C_STOP_INTERRUPT - STOP condition interrupt
EUSCI_B_I2C_START_INTERRUPT - START condition interrupt
EUSCI_B_I2C_TRANSMIT_INTERRUPT0 - Transmit interrupt0
EUSCI_B_I2C_TRANSMIT_INTERRUPT1 - Transmit interrupt1
EUSCI_B_I2C_TRANSMIT_INTERRUPT2 - Transmit interrupt2
EUSCI_B_I2C_TRANSMIT_INTERRUPT3 - Transmit interrupt3
EUSCI_B_I2C_RECEIVE_INTERRUPT0 - Receive interrupt0
EUSCI_B_I2C_RECEIVE_INTERRUPT1 - Receive interrupt1
EUSCI_B_I2C_RECEIVE_INTERRUPT2 - Receive interrupt2
EUSCI_B_I2C_RECEIVE_INTERRUPT3 - Receive interrupt3
EUSCI_B_I2C_BIT9_POSITION_INTERRUPT - Bit position 9 interrupt
EUSCI_B_I2C_CLOCK_LOW_TIMEOUT_INTERRUPT - Clock low timeout interrupt
enable
EUSCI_B_I2C_BYTE_COUNTER_INTERRUPT - Byte counter interrupt enable
Thu Jan 21 2016 12:34:41 AM
172
Inter-Integrated Circuit (I2C)
Returns
the masked status of the interrupt flag
EUSCI_B_I2C_STOP_INTERRUPT - STOP condition interrupt
EUSCI_B_I2C_START_INTERRUPT - START condition interrupt
EUSCI_B_I2C_TRANSMIT_INTERRUPT0 - Transmit interrupt0
EUSCI_B_I2C_TRANSMIT_INTERRUPT1 - Transmit interrupt1
EUSCI_B_I2C_TRANSMIT_INTERRUPT2 - Transmit interrupt2
EUSCI_B_I2C_TRANSMIT_INTERRUPT3 - Transmit interrupt3
EUSCI_B_I2C_RECEIVE_INTERRUPT0 - Receive interrupt0
EUSCI_B_I2C_RECEIVE_INTERRUPT1 - Receive interrupt1
EUSCI_B_I2C_RECEIVE_INTERRUPT2 - Receive interrupt2
EUSCI_B_I2C_RECEIVE_INTERRUPT3 - Receive interrupt3
EUSCI_B_I2C_NAK_INTERRUPT - Not-acknowledge interrupt
EUSCI_B_I2C_ARBITRATIONLOST_INTERRUPT - Arbitration lost interrupt
EUSCI_B_I2C_BIT9_POSITION_INTERRUPT - Bit position 9 interrupt enable
EUSCI_B_I2C_CLOCK_LOW_TIMEOUT_INTERRUPT - Clock low timeout interrupt
enable
EUSCI_B_I2C_BYTE_COUNTER_INTERRUPT - Byte counter interrupt enable
Referenced by I2C_getEnabledInterruptStatus().
11.6.2.10 uint_fast8_t I2C_getMode ( uint32_t moduleInstance )
Gets the mode of the I2C device.
Current I2C transmit/receive mode.
Parameters
moduleInstance
is the instance of the eUSCI B (I2C) module. Valid parameters vary from part to part, but
can include:
EUSCI_B0_BASE
EUSCI_B1_BASE
EUSCI_B2_BASE
EUSCI_B3_BASE
It is important to note that for eUSCI modules, only "B" modules such as EUSCI_B0
can be used. "A" modules such as EUSCI_A0 do not support the I2C mode.
Modified bits are UCTR of UCBxCTL1 register.
Returns
None Return one of the following:
EUSCI_B_I2C_TRANSMIT_MODE
EUSCI_B_I2C_RECEIVE_MODE
indicating the current mode
Thu Jan 21 2016 12:34:41 AM
173
Inter-Integrated Circuit (I2C)
11.6.2.11 uint32_t I2C_getReceiveBufferAddressForDMA ( uint32_t moduleInstance )
Returns the address of the RX Buffer of the I2C for the DMA module.
Thu Jan 21 2016 12:34:41 AM
174
Inter-Integrated Circuit (I2C)
Parameters
moduleInstance
is the instance of the eUSCI B (I2C) module. Valid parameters vary from part to part, but
can include:
EUSCI_B0_BASE
EUSCI_B1_BASE
EUSCI_B2_BASE
EUSCI_B3_BASE
It is important to note that for eUSCI modules, only "B" modules such as EUSCI_B0
can be used. "A" modules such as EUSCI_A0 do not support the I2C mode.
Returns the address of the I2C RX Buffer. This can be used in conjunction with the DMA to store
the received data directly to memory.
Returns
NONE
11.6.2.12 uint32_t I2C_getTransmitBufferAddressForDMA ( uint32_t moduleInstance )
Returns the address of the TX Buffer of the I2C for the DMA module.
Parameters
moduleInstance
is the instance of the eUSCI B (I2C) module. Valid parameters vary from part to part, but
can include:
EUSCI_B0_BASE
EUSCI_B1_BASE
EUSCI_B2_BASE
EUSCI_B3_BASE
It is important to note that for eUSCI modules, only "B" modules such as EUSCI_B0
can be used. "A" modules such as EUSCI_A0 do not support the I2C mode.
Returns the address of the I2C TX Buffer. This can be used in conjunction with the DMA to obtain
transmitted data directly from memory.
Returns
NONE
11.6.2.13 void I2C_initMaster ( uint32_t moduleInstance, const eUSCI_I2C_MasterConfig
∗ config )
Initializes the I2C Master block.
Thu Jan 21 2016 12:34:41 AM
175
Inter-Integrated Circuit (I2C)
Parameters
moduleInstance
is the instance of the eUSCI B (I2C) module. Valid parameters vary from part to part, but
can include:
EUSCI_B0_BASE
EUSCI_B1_BASE
EUSCI_B2_BASE
EUSCI_B3_BASE
It is important to note that for eUSCI modules, only "B" modules such as EUSCI_B0
can be used. "A" modules such as EUSCI_A0 do not support the I2C mode.
config
Configuration structure for I2C master mode
Configuration options for eUSCI_I2C_MasterConfig structure.
Parameters
selectClockSource
is the clock source. Valid values are
EUSCI_B_I2C_CLOCKSOURCE_ACLK
EUSCI_B_I2C_CLOCKSOURCE_SMCLK
i2cClk
dataRate
is the rate of the clock supplied to the I2C module (the frequency in Hz of the clock source
specified in selectClockSource).
set up for selecting data transfer rate. Valid values are
EUSCI_B_I2C_SET_DATA_RATE_1MBPS
EUSCI_B_I2C_SET_DATA_RATE_400KBPS
EUSCI_B_I2C_SET_DATA_RATE_100KBPS
byteCounterThreshold
autoSTOPGeneration
sets threshold for automatic STOP or UCSTPIFG
sets up the STOP condition generation. Valid values are
EUSCI_B_I2C_NO_AUTO_STOP
EUSCI_B_I2C_SET_BYTECOUNT_THRESHOLD_FLAG
EUSCI_B_I2C_SEND_STOP_AUTOMATICALLY_ON_BYTECOUNT_THRESHOLD
This function initializes operation of the I2C Master block. Upon successful initialization of the I2C
block, this function will have set the bus speed for the master; however I2C module is still disabled
till I2C_enableModule is invoked
Modified bits are UCMST, UCMODE_3, UCSYNC of UCBxCTL0 register UCSSELx, UCSWRST,
of UCBxCTL1 register UCBxBR0 and UCBxBR1 registers
Thu Jan 21 2016 12:34:41 AM
176
Inter-Integrated Circuit (I2C)
Returns
None.
11.6.2.14 void I2C_initSlave ( uint32_t moduleInstance, uint_fast16_t slaveAddress,
uint_fast8_t slaveAddressOffset, uint32_t slaveOwnAddressEnable )
Initializes the I2C Slave block.
Thu Jan 21 2016 12:34:41 AM
177
Inter-Integrated Circuit (I2C)
Parameters
moduleInstance
is the instance of the eUSCI B (I2C) module. Valid parameters vary from part to part, but
can include:
EUSCI_B0_BASE
EUSCI_B1_BASE
EUSCI_B2_BASE
EUSCI_B3_BASE
It is important to note that for eUSCI modules, only "B" modules such as EUSCI_B0
can be used. "A" modules such as EUSCI_A0 do not support the I2C mode.
slaveAddress
slaveAddressOffset
7-bit or 10-bit slave address
Own address Offset referred to- ’x’ value of UCBxI2COAx. Valid values are:
EUSCI_B_I2C_OWN_ADDRESS_OFFSET0,
EUSCI_B_I2C_OWN_ADDRESS_OFFSET1,
EUSCI_B_I2C_OWN_ADDRESS_OFFSET2,
EUSCI_B_I2C_OWN_ADDRESS_OFFSET3
slaveOwnAddressEnable
selects if the specified address is enabled or disabled. Valid values are:
EUSCI_B_I2C_OWN_ADDRESS_DISABLE,
EUSCI_B_I2C_OWN_ADDRESS_ENABLE
This function initializes operation of the I2C as a Slave mode. Upon successful initialization of the
I2C blocks, this function will have set the slave address but the I2C module is still disabled till
I2C_enableModule is invoked.
The parameter slaveAddress is the value that will be compared against the slave address sent by
an I2C master.
Modified bits are UCMODE_3, UCSYNC of UCBxCTL0 register UCSWRST of UCBxCTL1
register UCBxI2COA register
Returns
None.
11.6.2.15 uint8_t I2C_isBusBusy ( uint32_t moduleInstance )
Indicates whether or not the I2C bus is busy.
Thu Jan 21 2016 12:34:41 AM
178
Inter-Integrated Circuit (I2C)
Parameters
moduleInstance
is the instance of the eUSCI B (I2C) module. Valid parameters vary from part to part, but
can include:
EUSCI_B0_BASE
EUSCI_B1_BASE
EUSCI_B2_BASE
EUSCI_B3_BASE
It is important to note that for eUSCI modules, only "B" modules such as EUSCI_B0
can be used. "A" modules such as EUSCI_A0 do not support the I2C mode.
This function returns an indication of whether or not the I2C bus is busy.This function checks the
status of the bus via UCBBUSY bit in UCBxSTAT register.
Returns
Returns EUSCI_B_I2C_BUS_BUSY if the I2C Master is busy; otherwise, returns
EUSCI_B_I2C_BUS_NOT_BUSY.
11.6.2.16 bool I2C_masterIsStartSent ( uint32_t moduleInstance )
Indicates whether Start got sent.
Parameters
moduleInstance
is the instance of the eUSCI B (I2C) module. Valid parameters vary from part to part, but
can include:
EUSCI_B0_BASE
EUSCI_B1_BASE
EUSCI_B2_BASE
EUSCI_B3_BASE
It is important to note that for eUSCI modules, only "B" modules such as EUSCI_B0
can be used. "A" modules such as EUSCI_A0 do not support the I2C mode.
This function returns an indication of whether or not Start got sent This function checks the status
of the bus via UCTXSTT bit in UCBxCTL1 register.
Returns
Returns true if the START has been sent, false if it is sending
11.6.2.17 uint8_t I2C_masterIsStopSent ( uint32_t moduleInstance )
Indicates whether STOP got sent.
Thu Jan 21 2016 12:34:41 AM
179
Inter-Integrated Circuit (I2C)
Parameters
moduleInstance
is the instance of the eUSCI B (I2C) module. Valid parameters vary from part to part, but
can include:
EUSCI_B0_BASE
EUSCI_B1_BASE
EUSCI_B2_BASE
EUSCI_B3_BASE
It is important to note that for eUSCI modules, only "B" modules such as EUSCI_B0
can be used. "A" modules such as EUSCI_A0 do not support the I2C mode.
This function returns an indication of whether or not STOP got sent This function checks the status
of the bus via UCTXSTP bit in UCBxCTL1 register.
Returns
Returns EUSCI_B_I2C_STOP_SEND_COMPLETE if the I2C Master finished sending
STOP; otherwise, returns EUSCI_B_I2C_SENDING_STOP.
11.6.2.18 uint8_t I2C_masterReceiveMultiByteFinish ( uint32_t moduleInstance )
Finishes multi-byte reception at the Master end
Parameters
moduleInstance
is the instance of the eUSCI B (I2C) module. Valid parameters vary from part to part, but
can include:
EUSCI_B0_BASE
EUSCI_B1_BASE
EUSCI_B2_BASE
EUSCI_B3_BASE
It is important to note that for eUSCI modules, only "B" modules such as EUSCI_B0
can be used. "A" modules such as EUSCI_A0 do not support the I2C mode.
This function is used by the Master module to initiate completion of a multi-byte reception This
function
Receives the current byte and initiates the STOP from Master to Slave
Modified bits are UCTXSTP bit of UCBxCTL1.
Returns
Received byte at Master end.
11.6.2.19 bool I2C_masterReceiveMultiByteFinishWithTimeout ( uint32_t moduleInstance,
uint8_t ∗ txData, uint32_t timeout )
Finishes multi-byte reception at the Master end with timeout
Thu Jan 21 2016 12:34:41 AM
180
Inter-Integrated Circuit (I2C)
Parameters
moduleInstance
is the instance of the eUSCI B (I2C) module. Valid parameters vary from part to part, but
can include:
EUSCI_B0_BASE
EUSCI_B1_BASE
EUSCI_B2_BASE
EUSCI_B3_BASE
It is important to note that for eUSCI modules, only "B" modules such as EUSCI_B0
can be used. "A" modules such as EUSCI_A0 do not support the I2C mode.
txData
timeout
is a pointer to the location to store the received byte at master end
is the amount of time to wait until giving up
This function is used by the Master module to initiate completion of a multi-byte reception This
function
Receives the current byte and initiates the STOP from Master to Slave
Modified bits are UCTXSTP bit of UCBxCTL1.
Returns
0x01 or 0x00URE of the transmission process.
11.6.2.20 uint8_t I2C_masterReceiveMultiByteNext ( uint32_t moduleInstance )
Starts multi-byte reception at the Master end one byte at a time
Parameters
moduleInstance
is the instance of the eUSCI B (I2C) module. Valid parameters vary from part to part, but
can include:
EUSCI_B0_BASE
EUSCI_B1_BASE
EUSCI_B2_BASE
EUSCI_B3_BASE
It is important to note that for eUSCI modules, only "B" modules such as EUSCI_B0
can be used. "A" modules such as EUSCI_A0 do not support the I2C mode.
This function is used by the Master module to receive each byte of a multi-byte reception This
function reads currently received byte
Modified register is UCBxRXBUF.
Returns
Received byte at Master end.
11.6.2.21 void I2C_masterReceiveMultiByteStop ( uint32_t moduleInstance )
Sends the STOP at the end of a multi-byte reception at the Master end
Thu Jan 21 2016 12:34:41 AM
181
Inter-Integrated Circuit (I2C)
Parameters
moduleInstance
is the instance of the eUSCI B (I2C) module. Valid parameters vary from part to part, but
can include:
EUSCI_B0_BASE
EUSCI_B1_BASE
EUSCI_B2_BASE
EUSCI_B3_BASE
It is important to note that for eUSCI modules, only "B" modules such as EUSCI_B0
can be used. "A" modules such as EUSCI_A0 do not support the I2C mode.
This function is used by the Master module to initiate STOP
Modified bits are UCTXSTP bit of UCBxCTL1.
Returns
None.
11.6.2.22 uint8_t I2C_masterReceiveSingle ( uint32_t moduleInstance )
Receives a byte that has been sent to the I2C Master Module.
Parameters
moduleInstance
is the instance of the eUSCI B (I2C) module. Valid parameters vary from part to part, but
can include:
EUSCI_B0_BASE
EUSCI_B1_BASE
EUSCI_B2_BASE
EUSCI_B3_BASE
It is important to note that for eUSCI modules, only "B" modules such as EUSCI_B0
can be used. "A" modules such as EUSCI_A0 do not support the I2C mode.
This function reads a byte of data from the I2C receive data Register.
Thu Jan 21 2016 12:34:41 AM
182
Inter-Integrated Circuit (I2C)
Returns
Returns the byte received from by the I2C module, cast as an uint8_t.
11.6.2.23 uint8_t I2C_masterReceiveSingleByte ( uint32_t moduleInstance )
Does single byte reception from the slave
Parameters
moduleInstance
is the instance of the eUSCI B (I2C) module. Valid parameters vary from part to part, but
can include:
EUSCI_B0_BASE
EUSCI_B1_BASE
EUSCI_B2_BASE
EUSCI_B3_BASE
It is important to note that for eUSCI modules, only "B" modules such as EUSCI_B0
can be used. "A" modules such as EUSCI_A0 do not support the I2C mode.
This function is used by the Master module to receive a single byte. This function:
Sends START and STOP
Waits for data reception
Receives one byte from the Slave
Modified registers are UCBxIE, UCBxCTL1, UCBxIFG, UCBxTXBUF, UCBxIE
Returns
The byte that has been received from the slave
11.6.2.24 void I2C_masterReceiveStart ( uint32_t moduleInstance )
Starts reception at the Master end
Parameters
moduleInstance
is the instance of the eUSCI B (I2C) module. Valid parameters vary from part to part, but
can include:
EUSCI_B0_BASE
EUSCI_B1_BASE
EUSCI_B2_BASE
EUSCI_B3_BASE
It is important to note that for eUSCI modules, only "B" modules such as EUSCI_B0
can be used. "A" modules such as EUSCI_A0 do not support the I2C mode.
This function is used by the Master module initiate reception of a single byte. This function
Sends START
Thu Jan 21 2016 12:34:41 AM
183
Inter-Integrated Circuit (I2C)
Modified bits are UCTXSTT bit of UCBxCTL1.
Returns
None.
11.6.2.25 void I2C_masterSendMultiByteFinish ( uint32_t moduleInstance, uint8_t txData )
Finishes multi-byte transmission from Master to Slave
Parameters
moduleInstance
is the instance of the eUSCI B (I2C) module. Valid parameters vary from part to part, but
can include:
EUSCI_B0_BASE
EUSCI_B1_BASE
EUSCI_B2_BASE
EUSCI_B3_BASE
It is important to note that for eUSCI modules, only "B" modules such as EUSCI_B0
can be used. "A" modules such as EUSCI_A0 do not support the I2C mode.
txData
is the last data byte to be transmitted in a multi-byte transmsission
This function is used by the Master module to send the last byte and STOP. This function
Transmits the last data byte of a multi-byte transmission to the Slave
Sends STOP
Modified registers are UCBxTXBUF and UCBxCTL1.
Returns
None.
11.6.2.26 bool I2C_masterSendMultiByteFinishWithTimeout ( uint32_t moduleInstance,
uint8_t txData, uint32_t timeout )
Finishes multi-byte transmission from Master to Slave with timeout
Parameters
moduleInstance
is the instance of the eUSCI B (I2C) module. Valid parameters vary from part to part, but
can include:
EUSCI_B0_BASE
EUSCI_B1_BASE
EUSCI_B2_BASE
EUSCI_B3_BASE
It is important to note that for eUSCI modules, only "B" modules such as EUSCI_B0
can be used. "A" modules such as EUSCI_A0 do not support the I2C mode.
txData
timeout
Thu Jan 21 2016 12:34:41 AM
is the last data byte to be transmitted in a multi-byte transmission
is the amount of time to wait until giving up
184
Inter-Integrated Circuit (I2C)
This function is used by the Master module to send the last byte and STOP. This function
Transmits the last data byte of a multi-byte transmission to the Slave
Sends STOP
Modified registers are UCBxTXBUF and UCBxCTL1.
Returns
0x01 or 0x00URE of the transmission process.
11.6.2.27 void I2C_masterSendMultiByteNext ( uint32_t moduleInstance, uint8_t txData )
Continues multi-byte transmission from Master to Slave
Parameters
moduleInstance
is the instance of the eUSCI B (I2C) module. Valid parameters vary from part to part, but
can include:
EUSCI_B0_BASE
EUSCI_B1_BASE
EUSCI_B2_BASE
EUSCI_B3_BASE
It is important to note that for eUSCI modules, only "B" modules such as EUSCI_B0
can be used. "A" modules such as EUSCI_A0 do not support the I2C mode.
txData
is the next data byte to be transmitted
This function is used by the Master module continue each byte of a multi-byte trasmission. This
function
Transmits each data byte of a multi-byte transmission to the Slave
Modified registers are UCBxTXBUF
Returns
None.
11.6.2.28 bool I2C_masterSendMultiByteNextWithTimeout ( uint32_t moduleInstance,
uint8_t txData, uint32_t timeout )
Continues multi-byte transmission from Master to Slave with timeout
Thu Jan 21 2016 12:34:41 AM
185
Inter-Integrated Circuit (I2C)
Parameters
moduleInstance
is the instance of the eUSCI B (I2C) module. Valid parameters vary from part to part, but
can include:
EUSCI_B0_BASE
EUSCI_B1_BASE
EUSCI_B2_BASE
EUSCI_B3_BASE
It is important to note that for eUSCI modules, only "B" modules such as EUSCI_B0
can be used. "A" modules such as EUSCI_A0 do not support the I2C mode.
txData
timeout
is the next data byte to be transmitted
is the amount of time to wait until giving up
This function is used by the Master module continue each byte of a multi-byte transmission. This
function
Transmits each data byte of a multi-byte transmission to the Slave
Modified registers are UCBxTXBUF
Returns
0x01 or 0x00URE of the transmission process.
11.6.2.29 void I2C_masterSendMultiByteStart ( uint32_t moduleInstance, uint8_t txData )
Starts multi-byte transmission from Master to Slave
Parameters
moduleInstance
is the instance of the eUSCI B (I2C) module. Valid parameters vary from part to part, but
can include:
EUSCI_B0_BASE
EUSCI_B1_BASE
EUSCI_B2_BASE
EUSCI_B3_BASE
It is important to note that for eUSCI modules, only "B" modules such as EUSCI_B0
can be used. "A" modules such as EUSCI_A0 do not support the I2C mode.
txData
is the first data byte to be transmitted
This function is used by the Master module to send a single byte. This function
Sends START
Transmits the first data byte of a multi-byte transmission to the Slave
Modified registers are UCBxIE, UCBxCTL1, UCBxIFG, UCBxTXBUF, UCBxIE
Returns
None.
Thu Jan 21 2016 12:34:41 AM
186
Inter-Integrated Circuit (I2C)
11.6.2.30 bool I2C_masterSendMultiByteStartWithTimeout ( uint32_t moduleInstance,
uint8_t txData, uint32_t timeout )
Starts multi-byte transmission from Master to Slave with timeout
Thu Jan 21 2016 12:34:41 AM
187
Inter-Integrated Circuit (I2C)
Parameters
moduleInstance
is the instance of the eUSCI B (I2C) module. Valid parameters vary from part to part, but
can include:
EUSCI_B0_BASE
EUSCI_B1_BASE
EUSCI_B2_BASE
EUSCI_B3_BASE
It is important to note that for eUSCI modules, only "B" modules such as EUSCI_B0
can be used. "A" modules such as EUSCI_A0 do not support the I2C mode.
txData
timeout
is the first data byte to be transmitted
is the amount of time to wait until giving up
This function is used by the Master module to send a single byte. This function
Sends START
Transmits the first data byte of a multi-byte transmission to the Slave
Modified registers are UCBxIE, UCBxCTL1, UCBxIFG, UCBxTXBUF, UCBxIE
Returns
0x01 or 0x00URE of the transmission process.
11.6.2.31 void I2C_masterSendMultiByteStop ( uint32_t moduleInstance )
Send STOP byte at the end of a multi-byte transmission from Master to Slave
Parameters
moduleInstance
is the instance of the eUSCI B (I2C) module. Valid parameters vary from part to part, but
can include:
EUSCI_B0_BASE
EUSCI_B1_BASE
EUSCI_B2_BASE
EUSCI_B3_BASE
It is important to note that for eUSCI modules, only "B" modules such as EUSCI_B0
can be used. "A" modules such as EUSCI_A0 do not support the I2C mode.
This function is used by the Master module send STOP at the end of a multi-byte transmission
This function
Send a STOP after current transmission is complete
Modified bits are UCTXSTP bit of UCBxCTL1.
Returns
None.
Thu Jan 21 2016 12:34:41 AM
188
Inter-Integrated Circuit (I2C)
11.6.2.32 bool I2C_masterSendMultiByteStopWithTimeout ( uint32_t moduleInstance,
uint32_t timeout )
Send STOP byte at the end of a multi-byte transmission from Master to Slave with timeout
Thu Jan 21 2016 12:34:41 AM
189
Inter-Integrated Circuit (I2C)
Parameters
moduleInstance
is the instance of the eUSCI B (I2C) module. Valid parameters vary from part to part, but
can include:
EUSCI_B0_BASE
EUSCI_B1_BASE
EUSCI_B2_BASE
EUSCI_B3_BASE
It is important to note that for eUSCI modules, only "B" modules such as EUSCI_B0
can be used. "A" modules such as EUSCI_A0 do not support the I2C mode.
timeout
is the amount of time to wait until giving up
This function is used by the Master module send STOP at the end of a multi-byte transmission
This function
Send a STOP after current transmission is complete
Modified bits are UCTXSTP bit of UCBxCTL1.
Returns
0x01 or 0x00URE of the transmission process.
11.6.2.33 void I2C_masterSendSingleByte ( uint32_t moduleInstance, uint8_t txData )
Does single byte transmission from Master to Slave
Parameters
moduleInstance
is the instance of the eUSCI B (I2C) module. Valid parameters vary from part to part, but
can include:
EUSCI_B0_BASE
EUSCI_B1_BASE
EUSCI_B2_BASE
EUSCI_B3_BASE
It is important to note that for eUSCI modules, only "B" modules such as EUSCI_B0
can be used. "A" modules such as EUSCI_A0 do not support the I2C mode.
txData
is the data byte to be transmitted
This function is used by the Master module to send a single byte. This function
Sends START
Transmits the byte to the Slave
Sends STOP
Modified registers are UCBxIE, UCBxCTL1, UCBxIFG, UCBxTXBUF, UCBxIE
Returns
none
Thu Jan 21 2016 12:34:41 AM
190
Inter-Integrated Circuit (I2C)
11.6.2.34 bool I2C_masterSendSingleByteWithTimeout ( uint32_t moduleInstance, uint8_t
txData, uint32_t timeout )
Does single byte transmission from Master to Slave with timeout
Thu Jan 21 2016 12:34:41 AM
191
Inter-Integrated Circuit (I2C)
Parameters
moduleInstance
is the instance of the eUSCI B (I2C) module. Valid parameters vary from part to part, but
can include:
EUSCI_B0_BASE
EUSCI_B1_BASE
EUSCI_B2_BASE
EUSCI_B3_BASE
It is important to note that for eUSCI modules, only "B" modules such as EUSCI_B0
can be used. "A" modules such as EUSCI_A0 do not support the I2C mode.
txData
timeout
is the data byte to be transmitted
is the amount of time to wait until giving up
This function is used by the Master module to send a single byte. This function
Sends START
Transmits the byte to the Slave
Sends STOP
Modified registers are UCBxIE, UCBxCTL1, UCBxIFG, UCBxTXBUF, UCBxIE
Returns
0x01 or 0x00URE of the transmission process.
11.6.2.35 void I2C_masterSendStart ( uint32_t moduleInstance )
This function is used by the Master module to initiate START
Parameters
moduleInstance
is the instance of the eUSCI B (I2C) module. Valid parameters vary from part to part, but
can include:
EUSCI_B0_BASE
EUSCI_B1_BASE
EUSCI_B2_BASE
EUSCI_B3_BASE
It is important to note that for eUSCI modules, only "B" modules such as EUSCI_B0
can be used. "A" modules such as EUSCI_A0 do not support the I2C mode.
This function is used by the Master module to initiate STOP
Modified bits are UCTXSTT bit of UCBxCTLW0.
Thu Jan 21 2016 12:34:41 AM
192
Inter-Integrated Circuit (I2C)
Returns
None.
11.6.2.36 void I2C_registerInterrupt ( uint32_t moduleInstance, void(∗)(void) intHandler )
Registers an interrupt handler for I2C interrupts.
Thu Jan 21 2016 12:34:41 AM
193
Inter-Integrated Circuit (I2C)
Parameters
moduleInstance
is the instance of the eUSCI B (I2C) module. Valid parameters vary from part to part, but
can include:
EUSCI_B0_BASE
EUSCI_B1_BASE
EUSCI_B2_BASE
EUSCI_B3_BASE
It is important to note that for eUSCI modules, only "B" modules such as EUSCI_B0
can be used. "A" modules such as EUSCI_A0 do not support the I2C mode.
intHandler
is a pointer to the function to be called when the timer capture compare interrupt occurs.
This function registers the handler to be called when an I2C interrupt occurs. This function
enables the global interrupt in the interrupt controller; specific I2C interrupts must be enabled via
I2C_enableInterrupt(). It is the interrupt handler’s responsibility to clear the interrupt source via
I2C_clearInterruptFlag().
See Also
Interrupt_registerInterrupt() for important information about registering interrupt handlers.
Returns
None.
References Interrupt_enableInterrupt(), and Interrupt_registerInterrupt().
11.6.2.37 void I2C_setMode ( uint32_t moduleInstance, uint_fast8_t mode )
Sets the mode of the I2C device
Parameters
moduleInstance
is the instance of the eUSCI B (I2C) module. Valid parameters vary from part to part, but
can include:
EUSCI_B0_BASE
EUSCI_B1_BASE
EUSCI_B2_BASE
EUSCI_B3_BASE
It is important to note that for eUSCI modules, only "B" modules such as EUSCI_B0
can be used. "A" modules such as EUSCI_A0 do not support the I2C mode.
mode
indicates whether module is in transmit/receive mode
EUSCI_B_I2C_TRANSMIT_MODE
EUSCI_B_I2C_RECEIVE_MODE [Default value]
Modified bits are UCTR of UCBxCTL1 register
Thu Jan 21 2016 12:34:41 AM
194
Inter-Integrated Circuit (I2C)
Returns
None.
11.6.2.38 void I2C_setSlaveAddress ( uint32_t moduleInstance, uint_fast16_t
slaveAddress )
Sets the address that the I2C Master will place on the bus.
Parameters
moduleInstance
is the instance of the eUSCI B (I2C) module. Valid parameters vary from part to part, but
can include:
EUSCI_B0_BASE
EUSCI_B1_BASE
EUSCI_B2_BASE
EUSCI_B3_BASE
It is important to note that for eUSCI modules, only "B" modules such as EUSCI_B0
can be used. "A" modules such as EUSCI_A0 do not support the I2C mode.
slaveAddress
7-bit or 10-bit slave address
This function will set the address that the I2C Master will place on the bus when initiating a
transaction. Modified register is UCBxI2CSA register
Returns
None.
11.6.2.39 uint8_t I2C_slaveGetData ( uint32_t moduleInstance )
Receives a byte that has been sent to the I2C Module.
Parameters
moduleInstance
is the instance of the eUSCI B (I2C) module. Valid parameters vary from part to part, but
can include:
EUSCI_B0_BASE
EUSCI_B1_BASE
EUSCI_B2_BASE
EUSCI_B3_BASE
It is important to note that for eUSCI modules, only "B" modules such as EUSCI_B0
can be used. "A" modules such as EUSCI_A0 do not support the I2C mode.
This function reads a byte of data from the I2C receive data Register.
Returns
Returns the byte received from by the I2C module, cast as an uint8_t. Modified bit is
UCBxRXBUF register
Thu Jan 21 2016 12:34:41 AM
195
Inter-Integrated Circuit (I2C)
11.6.2.40 void I2C_slavePutData ( uint32_t moduleInstance, uint8_t transmitData )
Transmits a byte from the I2C Module.
Thu Jan 21 2016 12:34:41 AM
196
Inter-Integrated Circuit (I2C)
Parameters
moduleInstance
is the instance of the eUSCI B (I2C) module. Valid parameters vary from part to part, but
can include:
EUSCI_B0_BASE
EUSCI_B1_BASE
EUSCI_B2_BASE
EUSCI_B3_BASE
It is important to note that for eUSCI modules, only "B" modules such as EUSCI_B0
can be used. "A" modules such as EUSCI_A0 do not support the I2C mode.
transmitData
data to be transmitted from the I2C module
This function will place the supplied data into I2C transmit data register to start transmission
Modified register is UCBxTXBUF register
Returns
None.
11.6.2.41 void I2C_slaveSendNAK ( uint32_t moduleInstance )
This function is used by the slave to send a NAK out over the I2C line
Parameters
moduleInstance
is the instance of the eUSCI B (I2C) module. Valid parameters vary from part to part, but
can include:
EUSCI_B0_BASE
EUSCI_B1_BASE
EUSCI_B2_BASE
EUSCI_B3_BASE
It is important to note that for eUSCI modules, only "B" modules such as EUSCI_B0
can be used. "A" modules such as EUSCI_A0 do not support the I2C mode.
Thu Jan 21 2016 12:34:41 AM
197
Inter-Integrated Circuit (I2C)
Returns
None.
11.6.2.42 void I2C_unregisterInterrupt ( uint32_t moduleInstance )
Unregisters the interrupt handler for the timer
Parameters
moduleInstance
is the instance of the eUSCI B (I2C) module. Valid parameters vary from part to part, but
can include:
EUSCI_B0_BASE
EUSCI_B1_BASE
EUSCI_B2_BASE
EUSCI_B3_BASE
It is important to note that for eUSCI modules, only "B" modules such as EUSCI_B0
can be used. "A" modules such as EUSCI_A0 do not support the I2C mode.
This function unregisters the handler to be called when timer interrupt occurs. This function also
masks off the interrupt in the interrupt controller so that the interrupt handler no longer is called.
See Also
Interrupt_registerInterrupt() for important information about registering interrupt handlers.
Returns
None.
References Interrupt_disableInterrupt(), and Interrupt_unregisterInterrupt().
Thu Jan 21 2016 12:34:41 AM
198
Nested Vector Interrupt Controller (NVIC)
12
Nested Vector Interrupt Controller (NVIC)
Module Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .196
Basic Operation Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 197
Programming Example . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .197
Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 198
12.1
Module Operation
The interrupt controller API provides a set of functions for dealing with the Nested Vectored
Interrupt Controller (NVIC). Functions are provided to enable and disable interrupts, register
interrupt handlers, and set the priority of interrupts.
The NVIC provides global interrupt masking, prioritization, and handler dispatching. Individual
interrupt sources can be masked, and the processor interrupt can be globally masked as well
(without affecting the individual source masks).
The NVIC is tightly coupled with the Cortex-M microprocessor. When the processor responds to
an interrupt, the NVIC supplies the address of the function to handle the interrupt directly to the
processor. This action eliminates the need for a global interrupt handler that queries the interrupt
controller to determine the cause of the interrupt and branch to the appropriate handler, reducing
interrupt response time.
The interrupt prioritization in the NVIC allows higher priority interrupts to be handled before lower
priority interrupts, as well as allowing preemption of lower priority interrupt handlers by higher
priority interrupts. Again, this helps reduce interrupt response time (for example, a 1 ms system
control interrupt is not held off by the execution of a lower priority 1 second housekeeping interrupt
handler).
Sub-prioritization is also possible; instead of having N bits of preemptable prioritization, the NVIC
can be configured (via software) for N - M bits of preemptable prioritization and M bits of
sub-priority. In this scheme, two interrupts with the same preemptable prioritization but different
sub-priorities do not cause a preemption; tail chaining is used instead to process the two interrupts
back-to-back.
If two interrupts with the same priority (and sub-priority if so configured) are asserted at the same
time, the one with the lower interrupt number is processed first. The NVIC keeps track of the
nesting of interrupt handlers, allowing the processor to return from interrupt context only once all
nested and pending interrupts have been handled.
Interrupt handlers can be configured in one of two ways; statically at compile time or dynamically
at run time. Static configuration of interrupt handlers is accomplished by editing the interrupt
handler table in the application’s startup code. When statically configured, the interrupts must be
explicitly enabled in the NVIC via Interrupt_enableInterrupt() before the processor can respond to
the interrupt (in addition to any interrupt enabling required within the peripheral itself). Statically
configuring the interrupt table provides the fastest interrupt response time because the stacking
operation (a write to SRAM) can be performed in parallel with the interrupt handler table fetch (a
read from Flash), as well as the prefetch of the interrupt handler itself (assuming it is also in Flash).
Alternatively, interrupts can be configured at run-time using Interrupt_registerInterrupt(). When
using Interrupt_registerInterrupt(), the interrupt must also be enabled as before; when using the
analogue in each individual driver, Interrupt_enableInterrupt() is called by the driver and does not
need to be called by the application. Run-time configuration of interrupts adds a small latency to
Thu Jan 21 2016 12:34:41 AM
199
Nested Vector Interrupt Controller (NVIC)
the interrupt response time because the stacking operation (a write to SRAM) and the interrupt
handler table fetch (a read from SRAM) must be performed sequentially.
Run-time configuration of interrupt handlers requires that the interrupt handler table be placed on
a 1-kB boundary in SRAM (typically this is at the beginning of SRAM). Failure to do so results in
an incorrect vector address being fetched in response to an interrupt. The vector table is in a
section called “vtable” and should be placed appropriately with a linker script.
12.2
Basic Operation Modes
The primary function of the interrupt controller API is to manage the interrupt vector table used by
the NVIC to dispatch interrupt requests. Registering an interrupt handler is a simple matter of
inserting the handler address into the table. By default, the table is filled with pointers to an
internal handler that loops forever; it is an error for an interrupt to occur when there is no interrupt
handler registered to process it. Therefore, interrupt sources should not be enabled before a
handler has been registered, and interrupt sources should be disabled before a handler is
unregistered. Interrupt handlers are managed with Interrupt_registerInterrupt() and
Interrupt_unregisterInterrupt().
Each interrupt source can be individually enabled and disabled via Interrupt_enableInterrupt() and
Interrupt_disableInterrupt(). The processor interrupt can be enabled and disabled via
Interrupt_enableMaster() and Interrupt_disableMaster(); this does not affect the individual interrupt
enable states. Masking of the processor interrupt can be used as a simple critical section (only an
NMI can interrupt the processor while the processor interrupt is disabled), although masking the
processor interrupt can have adverse effects on the interrupt response time.
The priority of each interrupt source can be set and examined via Interrupt_setPriority() and
Interrupt_getPriority(). The priority assignments are defined by the hardware; the upper N bits of
the 8-bit priority are examined to determine the priority of an interrupt (for the MSP432 family, N is
3). This protocol allows priorities to be defined without knowledge of the exact number of
supported priorities; moving to a device with more or fewer priority bits is made easier as the
interrupt source continues to have a similar level of priority. Smaller priority numbers correspond to
higher interrupt priority, so 0 is the highest priority.
12.3
Programming Example
The DriverLib package contains a variety of different code examples that demonstrate the usage
of the Interrupt module. These code examples are accessible under the examples/ folder of the
MSPWare release as well as through TI Resource Explorer if using Code Composer Studio.
These code examples provide a comprehensive list of use cases as well as practical applications
involving each module.
Below is a very brief code example showing how to configure interrupt priorities. For a set of more
detailed code examples, please refer to the code examples in the examples/ directory of the
MSPWare release:
/* Configuring interrupt priorities */
MAP_Interrupt_setPriority(INT_EUSCIB0, 0x20);
MAP_Interrupt_setPriority(INT_EUSCIA0, 0x40);
Thu Jan 21 2016 12:34:41 AM
200
Nested Vector Interrupt Controller (NVIC)
12.4
Definitions
Functions
void Interrupt_disableInterrupt (uint32_t interruptNumber)
bool Interrupt_disableMaster (void)
void Interrupt_disableSleepOnIsrExit (void)
void Interrupt_enableInterrupt (uint32_t interruptNumber)
bool Interrupt_enableMaster (void)
void Interrupt_enableSleepOnIsrExit (void)
uint8_t Interrupt_getPriority (uint32_t interruptNumber)
uint32_t Interrupt_getPriorityGrouping (void)
uint8_t Interrupt_getPriorityMask (void)
uint32_t Interrupt_getVectorTableAddress (void)
bool Interrupt_isEnabled (uint32_t interruptNumber)
void Interrupt_pendInterrupt (uint32_t interruptNumber)
void Interrupt_registerInterrupt (uint32_t interruptNumber, void(∗intHandler)(void))
void Interrupt_setPriority (uint32_t interruptNumber, uint8_t priority)
void Interrupt_setPriorityGrouping (uint32_t bits)
void Interrupt_setPriorityMask (uint8_t priorityMask)
void Interrupt_setVectorTableAddress (uint32_t addr)
void Interrupt_unpendInterrupt (uint32_t interruptNumber)
void Interrupt_unregisterInterrupt (uint32_t interruptNumber)
12.4.1 Detailed Description
The code for this module is contained in driverlib/interrupt.c, with
driverlib/interrupt.h containing the API declarations for use by applications.
Thu Jan 21 2016 12:34:41 AM
201
Nested Vector Interrupt Controller (NVIC)
12.4.2 Function Documentation
12.4.2.1 void Interrupt_disableInterrupt ( uint32_t interruptNumber )
Disables an interrupt.
Parameters
interruptNumber
specifies the interrupt to be disabled.
The specified interrupt is disabled in the interrupt controller. Other enables for the interrupt (such
as at the peripheral level) are unaffected by this function.
See Interrupt_enableInterrupt for details about the interrupt parameter
Returns
None.
Referenced by ADC14_unregisterInterrupt(), AES256_unregisterInterrupt(),
COMP_E_unregisterInterrupt(), CS_unregisterInterrupt(), DMA_unregisterInterrupt(),
FlashCtl_unregisterInterrupt(), GPIO_unregisterInterrupt(), I2C_unregisterInterrupt(),
MPU_disableInterrupt(), PCM_unregisterInterrupt(), PSS_unregisterInterrupt(),
RTC_C_unregisterInterrupt(), SPI_unregisterInterrupt(), Timer32_unregisterInterrupt(),
Timer_A_unregisterInterrupt(), UART_unregisterInterrupt(), and WDT_A_unregisterInterrupt().
12.4.2.2 bool Interrupt_disableMaster ( void )
Disables the processor interrupt.
This function prevents the processor from receiving interrupts. This function does not affect the set
of interrupts enabled in the interrupt controller; it just gates the single interrupt from the controller
to the processor.
Returns
Returns true if interrupts were already disabled when the function was called or false if they
were initially enabled.
Referenced by FlashCtl_eraseSector(), FlashCtl_performMassErase(),
FlashCtl_programMemory(), FlashCtl_verifyMemory(), PCM_gotoLPM0InterruptSafe(),
PCM_gotoLPM3InterruptSafe(), and PCM_gotoLPM4InterruptSafe().
12.4.2.3 void Interrupt_disableSleepOnIsrExit ( void )
Disables the processor to sleep when exiting an ISR.
Returns
None
12.4.2.4 void Interrupt_enableInterrupt ( uint32_t interruptNumber )
Enables an interrupt.
Thu Jan 21 2016 12:34:41 AM
202
Nested Vector Interrupt Controller (NVIC)
Parameters
interruptNumber
specifies the interrupt to be enabled.
The specified interrupt is enabled in the interrupt controller. Other enables for the interrupt (such
as at the peripheral level) are unaffected by this function.
Valid values will vary from part to part, so it is important to check the device specific datasheet,
however for MSP432 101 the following values can be provided:
FAULT_NMI
FAULT_HARD
FAULT_MPU
FAULT_BUS
FAULT_USAGE
FAULT_SVCALL
FAULT_DEBUG
FAULT_PENDSV
FAULT_SYSTICK
INT_PSS
INT_CS
INT_PCM
INT_WDT_A
INT_FPU
INT_FLCTL
INT_COMP0
INT_COMP1
INT_TA0_0
INT_TA0_N
INT_TA1_0
INT_TA1_N
INT_TA2_0
INT_TA2_N
INT_TA3_0
INT_TA3_N
INT_EUSCIA0
INT_EUSCIA1
INT_EUSCIA2
INT_EUSCIA3
INT_EUSCIB0
INT_EUSCIB1
INT_EUSCIB2
INT_EUSCIB3
INT_ADC14
Thu Jan 21 2016 12:34:41 AM
203
Nested Vector Interrupt Controller (NVIC)
INT_T32_INT1
INT_T32_INT2
INT_T32_INTC
INT_AES
INT_RTCC
INT_DMA_ERR
INT_DMA_INT3
INT_DMA_INT2
INT_DMA_INT1
INT_DMA_INT0
INT_PORT1
INT_PORT2
INT_PORT3
INT_PORT4
INT_PORT5
INT_PORT6
Returns
None.
Referenced by ADC14_registerInterrupt(), AES256_registerInterrupt(),
COMP_E_registerInterrupt(), CS_registerInterrupt(), DMA_registerInterrupt(),
FlashCtl_registerInterrupt(), GPIO_registerInterrupt(), I2C_registerInterrupt(),
MPU_enableInterrupt(), PCM_registerInterrupt(), PSS_registerInterrupt(),
RTC_C_registerInterrupt(), SPI_registerInterrupt(), Timer32_registerInterrupt(),
Timer_A_registerInterrupt(), UART_registerInterrupt(), and WDT_A_registerInterrupt().
12.4.2.5 bool Interrupt_enableMaster ( void )
Enables the processor interrupt.
This function allows the processor to respond to interrupts. This function does not affect the set of
interrupts enabled in the interrupt controller; it just gates the single interrupt from the controller to
the processor.
Returns
Returns true if interrupts were disabled when the function was called or false if they were
initially enabled.
Referenced by FlashCtl_eraseSector(), FlashCtl_performMassErase(),
FlashCtl_programMemory(), FlashCtl_verifyMemory(), PCM_gotoLPM0InterruptSafe(),
PCM_gotoLPM3InterruptSafe(), and PCM_gotoLPM4InterruptSafe().
Thu Jan 21 2016 12:34:41 AM
204
Nested Vector Interrupt Controller (NVIC)
12.4.2.6 void Interrupt_enableSleepOnIsrExit ( void )
Enables the processor to sleep when exiting an ISR. For low power operation, this is ideal as
power cycles are not wasted with the processing required for waking up from an ISR and going
back to sleep.
Returns
None
12.4.2.7 uint8_t Interrupt_getPriority ( uint32_t interruptNumber )
Gets the priority of an interrupt.
Parameters
interruptNumber
specifies the interrupt in question.
This function gets the priority of an interrupt. See Interrupt_setPriority() for a definition of the
priority value.
See Interrupt_enableInterrupt for details about the interrupt parameter
Returns
Returns the interrupt priority, or -1 if an invalid interrupt was specified.
12.4.2.8 uint32_t Interrupt_getPriorityGrouping ( void )
Gets the priority grouping of the interrupt controller.
This function returns the split between preemptable priority levels and sub-priority levels in the
interrupt priority specification.
Returns
The number of bits of preemptable priority.
12.4.2.9 uint8_t Interrupt_getPriorityMask ( void )
Gets the priority masking level
This function gets the current setting of the interrupt priority masking level. The value returned is
the priority level such that all interrupts of that and lesser priority are masked. A value of 0 means
that priority masking is disabled.
Smaller numbers correspond to higher interrupt priorities. So for example a priority level mask of 4
allows interrupts of priority level 0-3, and interrupts with a numerical priority of 4 and greater are
blocked.
The hardware priority mechanism only looks at the upper N bits of the priority level (where N is 3
for the MSP432 family), so any prioritization must be performed in those bits.
Returns
Returns the value of the interrupt priority level mask.
Thu Jan 21 2016 12:34:41 AM
205
Nested Vector Interrupt Controller (NVIC)
12.4.2.10 uint32_t Interrupt_getVectorTableAddress ( void )
Returns the address of the interrupt vector table.
Returns
Address of the vector table.
12.4.2.11 bool Interrupt_isEnabled ( uint32_t interruptNumber )
Returns if a peripheral interrupt is enabled.
Parameters
interruptNumber
specifies the interrupt to check.
This function checks if the specified interrupt is enabled in the interrupt controller.
See Interrupt_enableInterrupt for details about the interrupt parameter
Returns
A non-zero value if the interrupt is enabled.
12.4.2.12 void Interrupt_pendInterrupt ( uint32_t interruptNumber )
Pends an interrupt.
Parameters
interruptNumber
specifies the interrupt to be pended.
The specified interrupt is pended in the interrupt controller. Pending an interrupt causes the
interrupt controller to execute the corresponding interrupt handler at the next available time, based
on the current interrupt state priorities. For example, if called by a higher priority interrupt handler,
the specified interrupt handler is not called until after the current interrupt handler has completed
execution. The interrupt must have been enabled for it to be called.
See Interrupt_enableInterrupt for details about the interrupt parameter
Returns
None.
12.4.2.13 void Interrupt_registerInterrupt ( uint32_t interruptNumber, void(∗)(void)
intHandler )
Registers a function to be called when an interrupt occurs.
Parameters
Thu Jan 21 2016 12:34:41 AM
206
Nested Vector Interrupt Controller (NVIC)
interruptNumber
intHandler
specifies the interrupt in question.
is a pointer to the function to be called.
Note
The use of this function (directly or indirectly via a peripheral driver interrupt register
function) moves the interrupt vector table from flash to SRAM. Therefore, care must be taken
when linking the application to ensure that the SRAM vector table is located at the beginning
of SRAM; otherwise the NVIC does not look in the correct portion of memory for the vector
table (it requires the vector table be on a 1 kB memory alignment). Normally, the SRAM
vector table is so placed via the use of linker scripts. See the discussion of compile-time
versus run-time interrupt handler registration in the introduction to this chapter.
This function is only used if the customer wants to specify the interrupt handler at run time.
In most cases, this is done through means of the user setting the ISR function pointer in the
startup file. Refer Refer to the Module Operation section for more details.
See Interrupt_enableInterrupt for details about the interrupt parameter
Returns
None.
Referenced by ADC14_registerInterrupt(), AES256_registerInterrupt(),
COMP_E_registerInterrupt(), CS_registerInterrupt(), DMA_registerInterrupt(),
FlashCtl_registerInterrupt(), GPIO_registerInterrupt(), I2C_registerInterrupt(),
MPU_registerInterrupt(), PCM_registerInterrupt(), PSS_registerInterrupt(),
RTC_C_registerInterrupt(), SPI_registerInterrupt(), SysTick_registerInterrupt(),
Timer32_registerInterrupt(), Timer_A_registerInterrupt(), UART_registerInterrupt(), and
WDT_A_registerInterrupt().
12.4.2.14 void Interrupt_setPriority ( uint32_t interruptNumber, uint8_t priority )
Sets the priority of an interrupt.
Parameters
interruptNumber
priority
specifies the interrupt in question.
specifies the priority of the interrupt.
This function is used to set the priority of an interrupt. When multiple interrupts are asserted
simultaneously, the ones with the highest priority are processed before the lower priority interrupts.
Smaller numbers correspond to higher interrupt priorities; priority 0 is the highest interrupt priority.
The hardware priority mechanism only looks at the upper N bits of the priority level (where N is 3
for the MSP432 family), so any prioritization must be performed in those bits. The remaining bits
can be used to sub-prioritize the interrupt sources, and may be used by the hardware priority
mechanism on a future part. This arrangement allows priorities to migrate to different NVIC
implementations without changing the gross prioritization of the interrupts.
See Interrupt_enableInterrupt for details about the interrupt parameter
Returns
None.
Thu Jan 21 2016 12:34:41 AM
207
Nested Vector Interrupt Controller (NVIC)
12.4.2.15 void Interrupt_setPriorityGrouping ( uint32_t bits )
Sets the priority grouping of the interrupt controller.
Thu Jan 21 2016 12:34:41 AM
208
Nested Vector Interrupt Controller (NVIC)
Parameters
bits
specifies the number of bits of preemptable priority.
This function specifies the split between preemptable priority levels and sub-priority levels in the
interrupt priority specification. The range of the grouping values are dependent upon the hardware
implementation; on the MSP432 family, three bits are available for hardware interrupt prioritization
and therefore priority grouping values of three through seven have the same effect.
Returns
None.
12.4.2.16 void Interrupt_setPriorityMask ( uint8_t priorityMask )
Sets the priority masking level
Parameters
priorityMask
is the priority level that is masked.
This function sets the interrupt priority masking level so that all interrupts at the specified or lesser
priority level are masked. Masking interrupts can be used to globally disable a set of interrupts
with priority below a predetermined threshold. A value of 0 disables priority masking.
Smaller numbers correspond to higher interrupt priorities. So for example a priority level mask of 4
allows interrupts of priority level 0-3, and interrupts with a numerical priority of 4 and greater are
blocked.
The hardware priority mechanism only looks at the upper N bits of the priority level (where N is 3
for the MSP432 family), so any prioritization must be performed in those bits.
Returns
None.
12.4.2.17 void Interrupt_setVectorTableAddress ( uint32_t addr )
Sets the address of the vector table. This function is for advanced users who might want to switch
between multiple instances of vector tables (perhaps between flash/ram).
Parameters
addr
is the new address of the vector table.
Returns
None.
12.4.2.18 void Interrupt_unpendInterrupt ( uint32_t interruptNumber )
Un-pends an interrupt.
Thu Jan 21 2016 12:34:41 AM
209
Nested Vector Interrupt Controller (NVIC)
Parameters
interruptNumber
specifies the interrupt to be un-pended.
The specified interrupt is un-pended in the interrupt controller. This will cause any previously
generated interrupts that have not been handled yet (due to higher priority interrupts or the
interrupt no having been enabled yet) to be discarded.
See Interrupt_enableInterrupt for details about the interrupt parameter
Returns
None.
12.4.2.19 void Interrupt_unregisterInterrupt ( uint32_t interruptNumber )
Unregisters the function to be called when an interrupt occurs.
Parameters
interruptNumber
specifies the interrupt in question.
This function is used to indicate that no handler should be called when the given interrupt is
asserted to the processor. The interrupt source is automatically disabled (via
Interrupt_disableInterrupt()) if necessary.
See Also
Interrupt_registerInterrupt() for important information about registering interrupt handlers.
See Interrupt_enableInterrupt for details about the interrupt parameter
Returns
None.
Referenced by ADC14_unregisterInterrupt(), AES256_unregisterInterrupt(),
COMP_E_unregisterInterrupt(), CS_unregisterInterrupt(), DMA_unregisterInterrupt(),
FlashCtl_unregisterInterrupt(), GPIO_unregisterInterrupt(), I2C_unregisterInterrupt(),
MPU_unregisterInterrupt(), PCM_unregisterInterrupt(), PSS_unregisterInterrupt(),
RTC_C_unregisterInterrupt(), SPI_unregisterInterrupt(), SysTick_unregisterInterrupt(),
Timer32_unregisterInterrupt(), Timer_A_unregisterInterrupt(), UART_unregisterInterrupt(), and
WDT_A_unregisterInterrupt().
Thu Jan 21 2016 12:34:41 AM
210
Memory Protection Unit (MPU)
13
Memory Protection Unit (MPU)
Module Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .208
Basic Operation Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 208
Repeat Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 209
Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 210
13.1
Module Operation
The Memory Protection Unit (MPU) API provides functions to configure the MPU. The MPU is
tightly coupled to the Cortex-M processor core and provides a means to establish access
permissions on regions of memory.
Up to eight memory regions can be defined. Each region has a base address and a size. The size
is specified as a power of 2 between 32 bytes and 4 GB, inclusive. The region’s base address
must be aligned to the size of the region. Each region also has access permissions. Code
execution can be allowed or disallowed for a region. A region can be configured for read-only
access, read/write access, or no access for both privileged and user modes. Access permissions
can be used to create an environment where only kernel or system code can access certain
hardware registers or sections of code.
The MPU creates 8 sub-regions within each region. Any sub-region or combination of sub-regions
can be disabled, allowing creation of “holes” or complex overlaying regions with different
permissions. The sub-regions can also be used to create an unaligned beginning or ending of a
region by disabling one or more of the leading or trailing sub-regions.
Once the regions are defined and the MPU is enabled, any access violation of a region causes a
memory management fault, and the fault handler is acted.
13.2
Module Operation
The MPU APIs provide a means to enable and configure the MPU and memory protection regions.
Generally, the memory protection regions should be defined before enabling the MPU. The
regions can be configured by calling MPU_setRegion() once for each region to be configured.
A region that is defined by MPU_setRegion() can be initially enabled or disabled. If the region is
not initially enabled, it can be enabled later by calling MPU_enableRegion(). An enabled region
can be disabled by calling MPU_disableRegion(). When a region is disabled, its configuration is
preserved as long as it is not overwritten. In this case, it can be enabled again with
MPU_enableRegion() without the need to reconfigure the region.
Care must be taken when setting up a protection region using MPU_setRegion(). The function
writes to multiple registers and is not protected from interrupts. Therefore, it is possible that an
interrupt which accesses a region may occur while that region is in the process of being changed.
The safest way to protect against this is to make sure that a region is always disabled before
making any changes. Otherwise, it is up to the caller to ensure that MPU_setRegion() is always
called from within code that cannot be interrupted, or from code that is not be affected if an
interrupt occurs while the region attributes are being changed.
The attributes of a region that have already been programmed can be retrieved and saved using
Thu Jan 21 2016 12:34:41 AM
211
Memory Protection Unit (MPU)
the MPU_getRegionCount() function. This function is intended to save the attributes in a format
that can be used later to reload the region using the MPU_setRegion() function. Note that the
enable state of the region is saved with the attributes and takes effect when the region is reloaded.
When one or more regions are defined, the MPU can be enabled by calling MPU_enableModule().
This function turns on the MPU and also defines the behavior in privileged mode and in the Hard
Fault and NMI fault handlers. The MPU can be configured so that when in privileged mode and no
regions are enabled, a default memory map is applied. If this feature is not enabled, then a
memory management fault is generated if the MPU is enabled and no regions are configured and
enabled. The MPU can also be set to use a default memory map when in the Hard Fault or NMI
handlers, instead of using the configured regions. All of these features are selected when calling
MPU_enableModule(). When the MPU is enabled, it can be disabled by calling
MPU_disableModule().
Finally, if the application is using run-time interrupt registration (see Interrupt_registerInterrupt()),
then the function MPU_registerInterrupt() can be used to install the fault handler which is called
whenever a memory protection violation occurs. This function also enables the fault handler. If
compile-time interrupt registration is used, then the Interrupt_enableInterrupt() function with the
parameter FAULT_MPU must be used to enable the memory management fault handler. When
the memory management fault handler has been installed with MPU_disableModule(), it can be
removed by calling MPU_unregisterInterrupt().
13.3
Programming Example
The DriverLib package contains a variety of different code examples that demonstrate the usage
of the MPU module. These code examples are accessible under the examples/ folder of the
MSPWare release as well as through TI Resource Explorer if using Code Composer Studio.
These code examples provide a comprehensive list of use cases as well as practical applications
involving each module.
Below is a very brief code example showing how to configure the MPU module to define a new
memory region and set it as read only:
Thu Jan 21 2016 12:34:41 AM
212
Memory Protection Unit (MPU)
13.4
Definitions
Functions
void MPU_disableInterrupt (void)
void MPU_disableModule (void)
void MPU_disableRegion (uint32_t region)
void MPU_enableInterrupt (void)
void MPU_enableModule (uint32_t mpuConfig)
void MPU_enableRegion (uint32_t region)
void MPU_getRegion (uint32_t region, uint32_t ∗addr, uint32_t ∗pflags)
uint32_t MPU_getRegionCount (void)
void MPU_registerInterrupt (void(∗intHandler)(void))
void MPU_setRegion (uint32_t region, uint32_t addr, uint32_t flags)
void MPU_unregisterInterrupt (void)
13.4.1 Detailed Description
The code for this module is contained in driverlib/mpu.c, with driverlib/mpu.h containing
the API declarations for use by applications.
Thu Jan 21 2016 12:34:41 AM
213
Memory Protection Unit (MPU)
13.4.2 Function Documentation
13.4.2.1 void MPU_disableInterrupt ( void )
Disables the interrupt for the memory management fault.
Returns
None.
References Interrupt_disableInterrupt().
13.4.2.2 void MPU_disableModule ( void )
Disables the MPU for use.
This function disables the Cortex-M memory protection unit. When the MPU is disabled, the
default memory map is used and memory management faults are not generated.
Returns
None.
13.4.2.3 void MPU_disableRegion ( uint32_t region )
Disables a specific region.
Parameters
region
is the region number to disable. Valid values are between 0 and 7 inclusively.
This function is used to disable a previously enabled memory protection region. The region
remains configured if it is not overwritten with another call to MPU_setRegion(), and can be
enabled again by calling MPU_enableRegion().
Returns
None.
13.4.2.4 void MPU_enableInterrupt ( void )
Enables the interrupt for the memory management fault.
Returns
None.
References Interrupt_enableInterrupt().
13.4.2.5 void MPU_enableModule ( uint32_t mpuConfig )
Enables and configures the MPU for use.
Thu Jan 21 2016 12:34:41 AM
214
Memory Protection Unit (MPU)
Parameters
mpuConfig
is the logical OR of the possible configurations.
This function enables the Cortex-M memory protection unit. It also configures the default behavior
when in privileged mode and while handling a hard fault or NMI. Prior to enabling the MPU, at
least one region must be set by calling MPU_setRegion() or else by enabling the default region for
privileged mode by passing the MPU_CONFIG_PRIV_DEFAULT flag to MPU_enableModule().
Once the MPU is enabled, a memory management fault is generated for memory access
violations.
The mpuConfig parameter should be the logical OR of any of the following:
MPU_CONFIG_PRIV_DEFAULT enables the default memory map when in privileged mode
and when no other regions are defined. If this option is not enabled, then there must be at
least one valid region already defined when the MPU is enabled.
MPU_CONFIG_HARDFLT_NMI enables the MPU while in a hard fault or NMI exception
handler. If this option is not enabled, then the MPU is disabled while in one of these
exception handlers and the default memory map is applied.
MPU_CONFIG_NONE chooses none of the above options. In this case, no default memory
map is provided in privileged mode, and the MPU is not enabled in the fault handlers.
Returns
None.
13.4.2.6 void MPU_enableRegion ( uint32_t region )
Enables a specific region.
Parameters
region
is the region number to enable. Valid values are between 0 and 7 inclusively.
This function is used to enable a memory protection region. The region should already be
configured with the MPU_setRegion() function. Once enabled, the memory protection rules of the
region are applied and access violations cause a memory management fault.
Returns
None.
13.4.2.7 void MPU_getRegion ( uint32_t region, uint32_t ∗ addr, uint32_t ∗ pflags )
Gets the current settings for a specific region.
Parameters
region
addr
Thu Jan 21 2016 12:34:41 AM
is the region number to get. Valid values are between 0 and 7 inclusively.
points to storage for the base address of the region.
215
Memory Protection Unit (MPU)
pflags
points to the attribute flags for the region.
This function retrieves the configuration of a specific region. The meanings and format of the
parameters is the same as that of the MPU_setRegion() function.
This function can be used to save the configuration of a region for later use with the
MPU_setRegion() function. The region’s enable state is preserved in the attributes that are saved.
Returns
None.
13.4.2.8 uint32_t MPU_getRegionCount ( void )
Gets the count of regions supported by the MPU.
This function is used to get the total number of regions that are supported by the MPU, including
regions that are already programmed.
Returns
The number of memory protection regions that are available for programming using
MPU_setRegion().
13.4.2.9 void MPU_registerInterrupt ( void(∗)(void) intHandler )
Registers an interrupt handler for the memory management fault.
Parameters
intHandler
is a pointer to the function to be called when the memory management fault occurs.
This function sets and enables the handler to be called when the MPU generates a memory
management fault due to a protection region access violation.
See Also
Interrupt_registerInterrupt() for important information about registering interrupt handlers.
Returns
None.
References Interrupt_registerInterrupt().
13.4.2.10 void MPU_setRegion ( uint32_t region, uint32_t addr, uint32_t flags )
Sets up the access rules for a specific region.
Parameters
region
Thu Jan 21 2016 12:34:41 AM
is the region number to set up.
216
Memory Protection Unit (MPU)
addr
flags
is the base address of the region. It must be aligned according to the size of the region
specified in flags.
is a set of flags to define the attributes of the region.
This function sets up the protection rules for a region. The region has a base address and a set of
attributes including the size. The base address parameter, addr, must be aligned according to the
size, and the size must be a power of 2.
Parameters
region
is the region number to set. Valid values are between 0 and 7 inclusively.
The flags parameter is the logical OR of all of the attributes of the region. It is a combination of
choices for region size, execute permission, read/write permissions, disabled sub-regions, and a
flag to determine if the region is enabled.
The size flag determines the size of a region and must be one of the following:
MPU_RGN_SIZE_32B
MPU_RGN_SIZE_64B
MPU_RGN_SIZE_128B
MPU_RGN_SIZE_256B
MPU_RGN_SIZE_512B
MPU_RGN_SIZE_1K
MPU_RGN_SIZE_2K
MPU_RGN_SIZE_4K
MPU_RGN_SIZE_8K
MPU_RGN_SIZE_16K
MPU_RGN_SIZE_32K
MPU_RGN_SIZE_64K
MPU_RGN_SIZE_128K
MPU_RGN_SIZE_256K
MPU_RGN_SIZE_512K
MPU_RGN_SIZE_1M
MPU_RGN_SIZE_2M
MPU_RGN_SIZE_4M
MPU_RGN_SIZE_8M
MPU_RGN_SIZE_16M
MPU_RGN_SIZE_32M
MPU_RGN_SIZE_64M
MPU_RGN_SIZE_128M
MPU_RGN_SIZE_256M
MPU_RGN_SIZE_512M
MPU_RGN_SIZE_1G
MPU_RGN_SIZE_2G
MPU_RGN_SIZE_4G
Thu Jan 21 2016 12:34:41 AM
217
Memory Protection Unit (MPU)
The execute permission flag must be one of the following:
MPU_RGN_PERM_EXEC enables the region for execution of code
MPU_RGN_PERM_NOEXEC disables the region for execution of code
The read/write access permissions are applied separately for the privileged and user modes. The
read/write access flags must be one of the following:
MPU_RGN_PERM_PRV_NO_USR_NO - no access in privileged or user mode
MPU_RGN_PERM_PRV_RW_USR_NO - privileged read/write, user no access
MPU_RGN_PERM_PRV_RW_USR_RO - privileged read/write, user read-only
MPU_RGN_PERM_PRV_RW_USR_RW - privileged read/write, user read/write
MPU_RGN_PERM_PRV_RO_USR_NO - privileged read-only, user no access
MPU_RGN_PERM_PRV_RO_USR_RO - privileged read-only, user read-only
The region is automatically divided into 8 equally-sized sub-regions by the MPU. Sub-regions can
only be used in regions of size 256 bytes or larger. Any of these 8 sub-regions can be disabled,
allowing for creation of “holes” in a region which can be left open, or overlaid by another region
with different attributes. Any of the 8 sub-regions can be disabled with a logical OR of any of the
following flags:
MPU_SUB_RGN_DISABLE_0
MPU_SUB_RGN_DISABLE_1
MPU_SUB_RGN_DISABLE_2
MPU_SUB_RGN_DISABLE_3
MPU_SUB_RGN_DISABLE_4
MPU_SUB_RGN_DISABLE_5
MPU_SUB_RGN_DISABLE_6
MPU_SUB_RGN_DISABLE_7
Finally, the region can be initially enabled or disabled with one of the following flags:
MPU_RGN_ENABLE
MPU_RGN_DISABLE
As an example, to set a region with the following attributes: size of 32 KB, execution enabled,
read-only for both privileged and user, one sub-region disabled, and initially enabled; the flags
parameter would have the following value:
(MPU_RGN_SIZE_32K | MPU_RGN_PERM_EXEC | MPU_RGN_PERM_PRV_RO_USR_RO |
MPU_SUB_RGN_DISABLE_2 | MPU_RGN_ENABLE)
Note
This function writes to multiple registers and is not protected from interrupts. It is possible
that an interrupt which accesses a region may occur while that region is in the process of
being changed. The safest way to handle this is to disable a region before changing it. Refer
to the discussion of this in the API Detailed Description section.
Returns
None.
Thu Jan 21 2016 12:34:41 AM
218
Memory Protection Unit (MPU)
13.4.2.11 void MPU_unregisterInterrupt ( void )
Unregisters an interrupt handler for the memory management fault.
This function disables and clears the handler to be called when a memory management fault
occurs.
See Also
Interrupt_registerInterrupt() for important information about registering interrupt handlers.
Returns
None.
References Interrupt_unregisterInterrupt().
Thu Jan 21 2016 12:34:41 AM
219
Power Control Module (PCM)
14
Power Control Module (PCM)
Module Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .217
Switching States . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 217
Switching Modes/Levels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 217
Low Power Mode and State Retention . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .218
Enabling/Disabling Rude Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 218
Programming Example . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .219
Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ??
14.1
Module Operation
The Power Control Manager (PCM) module for DriverLib is meant to simplify the management of
power states and provide a level of intelligence to users for switching between power states.
14.2
Switching States
One of the most useful features of the PCM module is the ability for the user to switch between
power states without having to worry about the logic requirements of the state transitions. By
using the PCM_setPowerState function, DriverLib will take in a parameter for the power state and
automatically handle all of the state transitions. Say that the user wants to switch to use the DCDC
converter with a voltage level of VCORE1 (PCM_AM_DCDC_VCORE1). Say that that same user
is currently in the default mode of using the LDO with a voltage level of VCORE0
(PCM_AM_LDO_VCORE0). Normally, the user would have to take into account that there is a
state transition that must happen to PCM_AM_LDO_VCORE1, however with the
PCM_setPowerState API the user does not need to worry about this. The call to change the power
state in this example would be:
PCM_setPowerState(PCM_AM_DCDC_VCORE1);
14.3
Switching Modes/Levels
In addition to being able to switch between individual power states, the PCM DriverLib API module
also gives the user the ability to switch between different power modes and levels. This gives the
user a more granular approach to power management and allows for a more refined customization
of the power driver.
For changing between power levels, the user will be able to switch back and forth between
PCM_VCORE0 and PCM_VCORE1 using the PCM_setCoreVoltageLevel function. While using
this function it is important to note that the underlying power mode will be preserved. For example,
if PCM_setCoreVoltageLevel is called with the PCM_VCORE1 parameter while the devices is in
PCM_AM_LDO_VCORE0 mode, the power state will be changed to PCM_AM_LDO_VCORE1. If
the same API is called with the same parameter in PCM_AM_DCDC_VCORE0 mode, the power
state will be changed to PCM_AM_DCDC_VCORE1 mode.
Thu Jan 21 2016 12:34:41 AM
220
Power Control Module (PCM)
The same preservation logic also applies while switching between power modes. If the
PCM_setPowerMode function is called with the PCM_DCDC_MODE parameter while the device is
in PCM_AM_LDO_VCORE0 mode, the device will change to PCM_AM_DCDC_VCORE0 mode
(leaving the voltage level unchanged).
14.4
Low Power Mode and State Retention
In addition to being able to manipulate individual states/modes/levels, APIs are also provided to
simplify entry into the low power modes of MSP432.
Low Power Entry Functions:
PCM_gotoLPM0
PCM_gotoLPM3
PCM_shutdownDevice
When using these low power modes entry functions, it is important to note that the original state of
the device before low power mode entry is retained. After the devices wakes up from low power
mode, the original power mode is restored. For example, say that the device is in
PCM_AM_DCDC_VCORE0 mode and then the user calls the PCM_gotoLPM3 API. Since
MSP432 devices are not allowed to go into LMP3 while in a DCDC power mode, the API will have
the intelligence to first change into PCM_AM_LDO_VCORE0 mode, and then go to LPM3. When
the device wakes up, the API will automatically switch back to PCM_AM_DCDC_VCORE0 mode.
If the user wants to go into DSL in the previous example without the state preservation, the
PCM_setPowerState function should be used with the PCM_LPM3 parameter.
14.5
Enabling/Disabling Rude Mode
If the user calls a low power entry function that disables a clock source while an active peripheral
is accessing the clock source, by default MSP432 will not allow the transition. This can be
enabled/disabled by using the PCM_enableRudeMode and PCM_disableRudeMode functions
respectively. By using these functions, the user can set the device to "force" its way into the low
power mode by forcibly halting any dependent clock resource.
Thu Jan 21 2016 12:34:41 AM
221
Power Control Module (PCM)
14.6
Programming Example
The DriverLib package contains a variety of different code examples that demonstrate the usage
of the PCM module. These code examples are accessible under the examples/ folder of the
MSPWare release as well as through TI Resource Explorer if using Code Composer Studio.
These code examples provide a comprehensive list of use cases as well as practical applications
involving each module.
Below is a very brief code example showing how to change power levels with the PCM module.
This is done in order to facilitate a higher frequency of 48Mhz. For a set of more detailed code
examples, please refer to the code examples in the examples/ directory of the MSPWare release:
/* Re-enabling port pin interrupt */
MAP_GPIO_clearInterruptFlag(GPIO_PORT_P1,
MAP_Interrupt_enableInterrupt(INT_PORT1);
MAP_Interrupt_enableMaster();
GPIO_PIN1);
/* Change to new power state */
MAP_PCM_setPowerState(powerStates[curPowerState]);
Thu Jan 21 2016 12:34:41 AM
222
Power Control Module (PCM)
14.7
Definitions
Functions
void PCM_clearInterruptFlag (uint32_t flags)
void PCM_disableInterrupt (uint32_t flags)
void PCM_disableRudeMode (void)
void PCM_enableInterrupt (uint32_t flags)
void PCM_enableRudeMode (void)
uint8_t PCM_getCoreVoltageLevel (void)
uint32_t PCM_getEnabledInterruptStatus (void)
uint32_t PCM_getInterruptStatus (void)
uint8_t PCM_getPowerMode (void)
uint8_t PCM_getPowerState (void)
bool PCM_gotoLPM0 (void)
bool PCM_gotoLPM0InterruptSafe (void)
bool PCM_gotoLPM3 (void)
bool PCM_gotoLPM3InterruptSafe (void)
bool PCM_gotoLPM4 (void)
bool PCM_gotoLPM4InterruptSafe (void)
void PCM_registerInterrupt (void(∗intHandler)(void))
bool PCM_setCoreVoltageLevel (uint_fast8_t voltageLevel)
bool PCM_setCoreVoltageLevelNonBlocking (uint_fast8_t voltageLevel)
bool PCM_setCoreVoltageLevelWithTimeout (uint_fast8_t voltageLevel, uint32_t timeOut)
bool PCM_setPowerMode (uint_fast8_t powerMode)
bool PCM_setPowerModeNonBlocking (uint_fast8_t powerMode)
bool PCM_setPowerModeWithTimeout (uint_fast8_t powerMode, uint32_t timeOut)
bool PCM_setPowerState (uint_fast8_t powerState)
bool PCM_setPowerStateNonBlocking (uint_fast8_t powerState)
bool PCM_setPowerStateWithTimeout (uint_fast8_t powerState, uint32_t timeout)
bool PCM_shutdownDevice (uint32_t shutdownMode)
void PCM_unregisterInterrupt (void)
14.7.1 Detailed Description
The code for this module is contained in driverlib/pcm.c, with driverlib/pcm.h containing
the API declarations for use by applications.
Thu Jan 21 2016 12:34:41 AM
223
Power Control Module (PCM)
14.7.2 Function Documentation
14.7.2.1 void PCM_clearInterruptFlag ( uint32_t flags )
Clears power system interrupt sources.
The specified power system interrupt sources are cleared, so that they no longer assert. This
function must be called in the interrupt handler to keep it from being called again immediately
upon exit.
Note
Because there is a write buffer in the Cortex-M processor, it may take several clock cycles
before the interrupt source is actually cleared. Therefore, it is recommended that the
interrupt source be cleared early in the interrupt handler (as opposed to the very last action)
to avoid returning from the interrupt handler before the interrupt source is actually cleared.
Failure to do so may result in the interrupt handler being immediately reentered (because the
interrupt controller still sees the interrupt source asserted).
Parameters
flags
is a bit mask of the interrupt sources to be cleared. Must be a logical OR of
PCM_DCDCERROR,
PCM_AM_INVALIDTRANSITION,
PCM_SM_INVALIDCLOCK,
PCM_SM_INVALIDTRANSITION
Note
The interrupt sources vary based on the part in use. Please consult the data sheet for the
part you are using to determine which interrupt sources are available.
Returns
None.
14.7.2.2 void PCM_disableInterrupt ( uint32_t flags )
Disables individual power control interrupt sources.
Parameters
flags
is a bit mask of the interrupt sources to be enabled. Must be a logical OR of:
PCM_DCDCERROR,
PCM_AM_INVALIDTRANSITION,
PCM_SM_INVALIDCLOCK,
PCM_SM_INVALIDTRANSITION
This function disables the indicated power control interrupt sources. Only the sources that are
enabled can be reflected to the processor interrupt; disabled sources have no effect on the
processor.
Thu Jan 21 2016 12:34:41 AM
224
Power Control Module (PCM)
Note
The interrupt sources vary based on the part in use. Please consult the data sheet for the
part you are using to determine which interrupt sources are available.
Returns
None.
14.7.2.3 void PCM_disableRudeMode ( void )
Disables "rude mode" entry into LPM3 and shutdown modes. With this mode disabled, an entry
into shutdown or LPM3 will wait for any active clock requests to free up before going into LPM3 or
shutdown.
Returns
None
14.7.2.4 void PCM_enableInterrupt ( uint32_t flags )
Enables individual power control interrupt sources.
Parameters
flags
is a bit mask of the interrupt sources to be enabled. Must be a logical OR of:
PCM_DCDCERROR,
PCM_AM_INVALIDTRANSITION,
PCM_SM_INVALIDCLOCK,
PCM_SM_INVALIDTRANSITION
This function enables the indicated power control interrupt sources. Only the sources that are
enabled can be reflected to the processor interrupt; disabled sources have no effect on the
processor.
Note
The interrupt sources vary based on the part in use. Please consult the data sheet for the
part you are using to determine which interrupt sources are available.
Returns
None.
14.7.2.5 void PCM_enableRudeMode ( void )
Enables "rude mode" entry into LPM3 and shutdown modes. With this mode enabled, an entry
into shutdown or LPM3 will occur even if there are clock systems active. The system will forcibly
turn off all clock/systems when going into these modes.
Returns
None
Thu Jan 21 2016 12:34:41 AM
225
Power Control Module (PCM)
14.7.2.6 uint8_t PCM_getCoreVoltageLevel ( void )
Returns the current powers state of the system see the PCM_setCoreVoltageLevel function for
specific information about the modes.
Returns
The current voltage of the system
Possible return values include:
PCM_VCORE0
PCM_VCORE1
PCM_VCORELPM3
References PCM_getPowerState().
14.7.2.7 uint32_t PCM_getEnabledInterruptStatus ( void )
Gets the current interrupt status masked with the enabled interrupts. This function is useful to call
in ISRs to get a list of pending interrupts that are actually enabled and could have caused the ISR.
Returns
The current interrupt status, enumerated as a bit field of:
PCM_DCDCERROR,
PCM_AM_INVALIDTRANSITION,
PCM_SM_INVALIDCLOCK,
PCM_SM_INVALIDTRANSITION
Note
The interrupt sources vary based on the part in use. Please consult the data sheet for the
part you are using to determine which interrupt sources are available.
References PCM_getInterruptStatus().
14.7.2.8 uint32_t PCM_getInterruptStatus ( void )
Gets the current interrupt status.
Returns
The current interrupt status, enumerated as a bit field of:
PCM_DCDCERROR,
PCM_AM_INVALIDTRANSITION,
PCM_SM_INVALIDCLOCK,
PCM_SM_INVALIDTRANSITION
Note
The interrupt sources vary based on the part in use. Please consult the data sheet for the
part you are using to determine which interrupt sources are available.
Referenced by PCM_getEnabledInterruptStatus().
Thu Jan 21 2016 12:34:41 AM
226
Power Control Module (PCM)
14.7.2.9 uint8_t PCM_getPowerMode ( void )
Returns the current powers state of the system see the PCM_setPowerState function for specific
information about the modes.
Returns
The current power mode of the system
References PCM_getPowerState().
Referenced by PCM_gotoLPM3().
14.7.2.10 uint8_t PCM_getPowerState ( void )
Returns the current powers state of the system see the PCMChangePowerState function for
specific information about the states.
Refer to PCM_setPowerState for possible return values.
Returns
The current power state of the system
Referenced by PCM_getCoreVoltageLevel(), PCM_getPowerMode(), and PCM_gotoLPM3().
14.7.2.11 bool PCM_gotoLPM0 ( void )
Transitions the device into LPM0.
Refer to the device specific data sheet for specifics about low power modes.
Returns
false if sleep state cannot be entered, true otherwise.
Referenced by PCM_gotoLPM0InterruptSafe().
14.7.2.12 bool PCM_gotoLPM0InterruptSafe ( void )
Transitions the device into LPM0 while maintaining a safe interrupt handling mentality. This
function is meant to be used in situations where the user wants to go to sleep, however does not
want to go to "miss" any interrupts due to the fact that going to LPM0 is not an atomic operation.
This function will modify the PRIMASK and on exit of the program the master interrupts will be
disabled.
Refer to the device specific data sheet for specifics about low power modes.
Returns
false if sleep state cannot be entered, true otherwise.
References Interrupt_disableMaster(), Interrupt_enableMaster(), and PCM_gotoLPM0().
Thu Jan 21 2016 12:34:41 AM
227
Power Control Module (PCM)
14.7.2.13 bool PCM_gotoLPM3 ( void )
Transitions the device into LPM3
Refer to the device specific data sheet for specifics about low power modes. Note that since LPM3
cannot be entered from a DCDC power modes, the power mode is first switched to LDO operation
(if in DCDC mode), the deep sleep is entered, and the DCDC mode is restored on wake up.
Returns
false if sleep state cannot be entered, true otherwise.
References PCM_getPowerMode(), PCM_getPowerState(), PCM_setPowerMode(), and
PCM_setPowerState().
Referenced by PCM_gotoLPM3InterruptSafe(), and PCM_gotoLPM4().
14.7.2.14 bool PCM_gotoLPM3InterruptSafe ( void )
Transitions the device into LPM3 while maintaining a safe interrupt handling mentality. This
function is meant to be used in situations where the user wants to go to LPM3, however does not
want to go to "miss" any interrupts due to the fact that going to LPM3 is not an atomic operation.
This function will modify the PRIMASK and on exit of the program the master interrupts will be
disabled.
Refer to the device specific data sheet for specifics about low power modes. Note that since LPM3
cannot be entered from a DCDC power modes, the power mode is first switched to LDO operation
(if in DCDC mode), the deep sleep is entered, and the DCDC mode is restored on wake up.
Returns
false if sleep state cannot be entered, true otherwise.
References Interrupt_disableMaster(), Interrupt_enableMaster(), and PCM_gotoLPM3().
14.7.2.15 bool PCM_gotoLPM4 ( void )
Transitions the device into LPM4. LPM4 is the exact same with LPM3, just with RTC_C and
WDT_A disabled. When waking up, RTC_C and WDT_A will remain disabled until reconfigured by
the user.
Returns
false if sleep state cannot be entered, true otherwise.
References PCM_gotoLPM3(), RTC_C_holdClock(), and WDT_A_holdTimer().
Referenced by PCM_gotoLPM4InterruptSafe().
14.7.2.16 bool PCM_gotoLPM4InterruptSafe ( void )
Transitions the device into LPM4 while maintaining a safe interrupt handling mentality. This
function is meant to be used in situations where the user wants to go to LPM4, however does not
want to go to "miss" any interrupts due to the fact that going to LPM4 is not an atomic operation.
Thu Jan 21 2016 12:34:41 AM
228
Power Control Module (PCM)
This function will modify the PRIMASK and on exit of the program the master interrupts will be
disabled.
Refer to the device specific data sheet for specifics about low power modes. Note that since LPM3
cannot be entered from a DCDC power modes, the power mode is first switched to LDO operation
(if in DCDC mode), the deep sleep is entered, and the DCDC mode is restored on wake up.
Returns
false if sleep state cannot be entered, true otherwise.
References Interrupt_disableMaster(), Interrupt_enableMaster(), and PCM_gotoLPM4().
14.7.2.17 void PCM_registerInterrupt ( void(∗)(void) intHandler )
Registers an interrupt handler for the power system interrupt.
Parameters
intHandler
is a pointer to the function to be called when the power system interrupt occurs.
This function registers the handler to be called when a clock system interrupt occurs. This function
enables the global interrupt in the interrupt controller; specific PCM interrupts must be enabled via
PCM_enableInterrupt(). It is the interrupt handler’s responsibility to clear the interrupt source via
PCM_clearInterruptFlag .
See Also
Interrupt_registerInterrupt() for important information about registering interrupt handlers.
Returns
None.
References Interrupt_enableInterrupt(), and Interrupt_registerInterrupt().
14.7.2.18 bool PCM_setCoreVoltageLevel ( uint_fast8_t voltageLevel )
Sets the core voltage level (Vcore). The function will take care of all power state transitions
needed to shift between core voltage levels. Because transitions between voltage levels may
require changes power modes, the power mode might temporarily be change. The power mode
will be returned to the original state (with the new voltage level) at the end of a successful
execution of this function.
Refer to the device specific data sheet for specifics about core voltage levels.
Parameters
voltageLevel
The voltage level to be shifted to.
PCM_VCORE0,
PCM_VCORE1
Returns
true if voltage level set, false otherwise.
Thu Jan 21 2016 12:34:41 AM
229
Power Control Module (PCM)
14.7.2.19 bool PCM_setCoreVoltageLevelNonBlocking ( uint_fast8_t voltageLevel )
Sets the core voltage level (Vcore). This function is similar to PCM_setCoreVoltageLevel, however
there are no polling flags to ensure a state has changed. Execution is returned back to the calling
program correctly. For MSP432, changing into different power modes/states require very specific
logic. This function will initiate only one state transition and then return. It is up to the user to keep
calling this function until the correct power state has been achieved.
Refer to the device specific data sheet for specifics about core voltage levels.
Parameters
voltageLevel
The voltage level to be shifted to.
PCM_VCORE0,
PCM_VCORE1
Returns
true if voltage level set, false otherwise.
14.7.2.20 bool PCM_setCoreVoltageLevelWithTimeout ( uint_fast8_t voltageLevel, uint32_t
timeOut )
Sets the core voltage level (Vcore). This function will take care of all power state transitions
needed to shift between core voltage levels. Because transitions between voltage levels may
require changes power modes, the power mode might temporarily be change. The power mode
will be returned to the original state (with the new voltage level) at the end of a successful
execution of this function.
This function is similar to PCMSetCoreVoltageLevel, however a timeout mechanism is used.
Refer to the device specific data sheet for specifics about core voltage levels.
Parameters
voltageLevel
The voltage level to be shifted to.
PCM_VCORE0,
PCM_VCORE1
timeOut
Number of loop iterations to timeout when checking for power state transitions. This
should be used for debugging initial power/hardware configurations. After a stable hardware base is established, the PCMSetCoreVoltageLevel function should be used
Returns
true if voltage level set, false otherwise.
14.7.2.21 bool PCM_setPowerMode ( uint_fast8_t powerMode )
Switches between power modes. This function will take care of all power state transitions needed
to shift between power modes. Note for changing to DCDC mode, specific hardware
considerations are required.
Thu Jan 21 2016 12:34:41 AM
230
Power Control Module (PCM)
Refer to the device specific data sheet for specifics about power modes.
Thu Jan 21 2016 12:34:41 AM
231
Power Control Module (PCM)
Parameters
powerMode
The voltage modes to be shifted to. Valid values are:
PCM_LDO_MODE,
PCM_DCDC_MODE,
PCM_LF_MODE
Returns
true if power mode is set, false otherwise.
Referenced by PCM_gotoLPM3().
14.7.2.22 bool PCM_setPowerModeNonBlocking ( uint_fast8_t powerMode )
Sets the core voltage level (Vcore). This function is similar to PCM_setPowerMode, however there
are no polling flags to ensure a state has changed. Execution is returned back to the calling
program correctly. For MSP432, changing into different power modes/states require very specific
logic. This function will initiate only one state transition and then return. It is up to the user to keep
calling this function until the correct power state has been achieved.
Refer to the device specific data sheet for specifics about core voltage levels.
Parameters
powerMode
The voltage modes to be shifted to. Valid values are:
PCM_LDO_MODE,
PCM_DCDC_MODE,
PCM_LF_MODE
Returns
true if power mode change was initiated, false otherwise
14.7.2.23 bool PCM_setPowerModeWithTimeout ( uint_fast8_t powerMode, uint32_t
timeOut )
Switches between power modes. This function will take care of all power state transitions needed
to shift between power modes. Note for changing to DCDC mode, specific hardware
considerations are required.
This function is similar to PCMSetPowerMode, however a timeout mechanism is used.
Refer to the device specific data sheet for specifics about power modes.
Thu Jan 21 2016 12:34:41 AM
232
Power Control Module (PCM)
Parameters
powerMode
The voltage modes to be shifted to. Valid values are:
PCM_LDO_MODE,
PCM_DCDC_MODE,
PCM_LF_MODE
timeOut
Number of loop iterations to timeout when checking for power state transitions. This
should be used for debugging initial power/hardware configurations. After a stable hardware base is established, the PCMSetPowerMode function should be used
Returns
true if power mode is set, false otherwise.
14.7.2.24 bool PCM_setPowerState ( uint_fast8_t powerState )
Switches between power states. This is a convenience function that combines the functionality of
PCM_setPowerMode and PCM_setCoreVoltageLevel as well as the LPM0/LPM3 functions.
Refer to the device specific data sheet for specifics about power states.
Parameters
powerState
The voltage modes to be shifted to. Valid values are:
PCM_AM_LDO_VCORE0, [Active Mode, LDO, VCORE0]
PCM_AM_LDO_VCORE1, [Active Mode, LDO, VCORE1]
PCM_AM_DCDC_VCORE0, [Active Mode, DCDC, VCORE0]
PCM_AM_DCDC_VCORE1, [Active Mode, DCDC, VCORE1]
PCM_AM_LF_VCORE0, [Active Mode, Low Frequency, VCORE0]
PCM_AM_LF_VCORE1, [Active Mode, Low Frequency, VCORE1]
PCM_LPM0_LDO_VCORE0, [LMP0, LDO, VCORE0]
PCM_LPM0_LDO_VCORE1, [LMP0, LDO, VCORE1]
PCM_LPM0_DCDC_VCORE0, [LMP0, DCDC, VCORE0]
PCM_LPM0_DCDC_VCORE1, [LMP0, DCDC, VCORE1]
PCM_LPM0_LF_VCORE0, [LMP0, Low Frequency, VCORE0]
PCM_LPM0_LF_VCORE1, [LMP0, Low Frequency, VCORE1]
PCM_LPM3, [LPM3]
PCM_LPM35_VCORE0, [LPM3.5 VCORE 0]
PCM_LPM4, [LPM4]
PCM_LPM45, [LPM4.5]
Returns
true if power state is set, false otherwise.
Referenced by PCM_gotoLPM3().
Thu Jan 21 2016 12:34:41 AM
233
Power Control Module (PCM)
14.7.2.25 bool PCM_setPowerStateNonBlocking ( uint_fast8_t powerState )
Sets the power state of the part. This function is similar to PCM_getPowerState, however there
are no polling flags to ensure a state has changed. Execution is returned back to the calling
program correctly. For MSP432, changing into different power modes/states require very specific
logic. This function will initiate only one state transition and then return. It is up to the user to keep
calling this function until the correct power state has been achieved.
Refer to the device specific data sheet for specifics about core voltage levels.
Parameters
powerState
The voltage modes to be shifted to. Valid values are:
PCM_AM_LDO_VCORE0, [Active Mode, LDO, VCORE0]
PCM_AM_LDO_VCORE1, [Active Mode, LDO, VCORE1]
PCM_AM_DCDC_VCORE0, [Active Mode, DCDC, VCORE0]
PCM_AM_DCDC_VCORE1, [Active Mode, DCDC, VCORE1]
PCM_AM_LF_VCORE0, [Active Mode, Low Frequency, VCORE0]
PCM_AM_LF_VCORE1, [Active Mode, Low Frequency, VCORE1]
PCM_LPM0_LDO_VCORE0, [LMP0, LDO, VCORE0]
PCM_LPM0_LDO_VCORE1, [LMP0, LDO, VCORE1]
PCM_LPM0_DCDC_VCORE0, [LMP0, DCDC, VCORE0]
PCM_LPM0_DCDC_VCORE1, [LMP0, DCDC, VCORE1]
PCM_LPM0_LF_VCORE0, [LMP0, Low Frequency, VCORE0]
PCM_LPM0_LF_VCORE1, [LMP0, Low Frequency, VCORE1]
PCM_LPM3, [LPM3]
PCM_LPM35_VCORE0, [LPM3.5 VCORE 0]
PCM_LPM45, [LPM4.5]
Returns
true if power state change was initiated, false otherwise
14.7.2.26 bool PCM_setPowerStateWithTimeout ( uint_fast8_t powerState, uint32_t
timeout )
Switches between power states. This is a convenience function that combines the functionality of
PCM_setPowerMode and PCM_setCoreVoltageLevel as well as the LPM modes.
This function is similar to PCM_setPowerState, however a timeout mechanism is used.
Refer to the device specific data sheet for specifics about power states.
Parameters
Thu Jan 21 2016 12:34:41 AM
234
Power Control Module (PCM)
powerState
The voltage modes to be shifted to. Valid values are:
PCM_AM_LDO_VCORE0, [Active Mode, LDO, VCORE0]
PCM_AM_LDO_VCORE1, [Active Mode, LDO, VCORE1]
PCM_AM_DCDC_VCORE0, [Active Mode, DCDC, VCORE0]
PCM_AM_DCDC_VCORE1, [Active Mode, DCDC, VCORE1]
PCM_AM_LF_VCORE0, [Active Mode, Low Frequency, VCORE0]
PCM_AM_LF_VCORE1, [Active Mode, Low Frequency, VCORE1]
PCM_LPM0_LDO_VCORE0, [LMP0, LDO, VCORE0]
PCM_LPM0_LDO_VCORE1, [LMP0, LDO, VCORE1]
PCM_LPM0_DCDC_VCORE0, [LMP0, DCDC, VCORE0]
PCM_LPM0_DCDC_VCORE1, [LMP0, DCDC, VCORE1]
PCM_LPM0_LF_VCORE0, [LMP0, Low Frequency, VCORE0]
PCM_LPM0_LF_VCORE1, [LMP0, Low Frequency, VCORE1]
PCM_LPM3, [LPM3]
PCM_LPM35_VCORE0, [LPM3.5 VCORE 0]
PCM_LPM4, [LPM4]
PCM_LPM45, [LPM4.5]
timeout
Number of loop iterations to timeout when checking for power state transitions. This
should be used for debugging initial power/hardware configurations. After a stable hardware base is established, the PCMSetPowerMode function should be used
Returns
true if power state is set, false otherwise. It is important to note that if a timeout occurs, false
will be returned, however the power state at this point is not guaranteed to be the same as
the state prior to the function call
14.7.2.27 bool PCM_shutdownDevice ( uint32_t shutdownMode )
Transitions the device into LPM3.5/LPM4.5 mode.
Refer to the device specific data sheet for specifics about shutdown modes.
The following events will cause a wake up from LPM3.5 mode:
Device reset
External reset RST
Enabled RTC, WDT, and wake-up I/O only interrupt events
The following events will cause a wake up from the LPM4.5 mode:
Device reset
External reset RST
Wake-up I/O only interrupt events
Thu Jan 21 2016 12:34:41 AM
235
Power Control Module (PCM)
Parameters
shutdownMode
Specific mode to go to. Valid values are:
PCM_LPM35_VCORE0
PCM_LPM45
Returns
false if shutdown state cannot be entered, true otherwise.
14.7.2.28 void PCM_unregisterInterrupt ( void )
Unregisters the interrupt handler for the power system.
This function unregisters the handler to be called when a power system interrupt occurs. This
function also masks off the interrupt in the interrupt controller so that the interrupt handler no
longer is called.
See Also
Interrupt_registerInterrupt() for important information about registering interrupt handlers.
Returns
None.
References Interrupt_disableInterrupt(), and Interrupt_unregisterInterrupt().
Thu Jan 21 2016 12:34:41 AM
236
Port Mapper (PMAP)
15
Port Mapper (PMAP)
Module Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 235
Programming Example . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .235
Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 236
15.1
Module Operation
The port mapping controller allows the flexible and reconfigurable mapping of digital functions to
port pins.
The port mapping controller features are:
Configuration protected by write access key.
Default mapping provided for each port pin (device-dependent, the device pinout in the
device-specific data sheet).
Mapping can be reconfigured during runtime.
Each output signal can be mapped to several output pins.
15.2
Programming Example
The DriverLib package contains a variety of different code examples that demonstrate the usage
of the PMAP module. These code examples are accessible under the examples/ folder of the
MSPWare release as well as through TI Resource Explorer if using Code Composer Studio.
These code examples provide a comprehensive list of use cases as well as practical applications
involving each module.
Below is a very brief code example showing how to use the PMAP module to redirect the output of
a TimerA CCR register.
First is the array configuration to remap the port:
/* Port mapper configuration register */
const uint8_t port_mapping[] =
{
//Port P2:
PM_NONE, PM_NONE, PM_NONE, PM_NONE,
PM_NONE
};
PM_TA1CCR1A,
PM_NONE,
PM_NONE,
Next is the call to the actual PMAP API that persists the configuration:
/* Remapping TACCR0 to P2.4 */
MAP_PMAP_configurePorts((const uint8_t *) port_mapping,
PMAP_DISABLE_RECONFIGURATION);
Thu Jan 21 2016 12:34:41 AM
PMAP_P2MAP,
1,
237
Port Mapper (PMAP)
15.3
Definitions
Functions
void PMAP_configurePorts (const uint8_t ∗portMapping, uint8_t pxMAPy, uint8_t
numberOfPorts, uint8_t portMapReconfigure)
15.3.1 Detailed Description
The code for this module is contained in driverlib/pmap.c, with driverlib/pmap.h
containing the API declarations for use by applications.
Thu Jan 21 2016 12:34:41 AM
238
Port Mapper (PMAP)
15.3.2 Function Documentation
15.3.2.1 void PMAP_configurePorts ( const uint8_t ∗ portMapping, uint8_t pxMAPy,
uint8_t numberOfPorts, uint8_t portMapReconfigure )
This function configures the MSP432 Port Mapper
Parameters
portMapping
pxMAPy
numberOfPorts
portMapReconfigure
is the pointer to init Data
is the Port Mapper to initialize
is the number of Ports to initialize
is
used
to
enable/disable
reconfiguration
Valid
values
are
PMAP_ENABLE_RECONFIGURATION
PMAP_DISABLE_RECONFIGURATION
[Default value] Modified registers are PMAPKEYID, PMAPCTL
Returns
None
Thu Jan 21 2016 12:34:41 AM
239
Power Supply System (PSS)
16
Power Supply System (PSS)
Module Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .238
Programming Example . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .238
Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 239
16.1
Module Operation
The PSS module for the DriverLib allows the user to fully configure/setup the various analog
power sources on the MSP432 device. This mainly involves enabling and disabling the high side
supervisor/monitor. Performance modes of both the high side power supply can be configured and
manipulated in order to optimize power efficiency. Additionally, the PSS interrupt can be
configured to fire an interrupt on a power supply violation.
16.2
Programming Example
The DriverLib package contains a variety of different code examples that demonstrate the usage
of the PSS module. These code examples are accessible under the examples/ folder of the
MSPWare release as well as through TI Resource Explorer if using Code Composer Studio.
These code examples provide a comprehensive list of use cases as well as practical applications
involving each module.
Below is a very brief code example showing how to disable the high side power supervisor:
MAP_PSS_enableHighSide();
Thu Jan 21 2016 12:34:41 AM
240
Power Supply System (PSS)
16.3
Definitions
Functions
void PSS_clearInterruptFlag (void)
void PSS_disableForcedDCDCOperation (void)
void PSS_disableHighSide (void)
void PSS_disableHighSideMonitor (void)
void PSS_disableHighSidePinToggle (void)
void PSS_disableInterrupt (void)
void PSS_enableForcedDCDCOperation (void)
void PSS_enableHighSide (void)
void PSS_enableHighSideMonitor (void)
void PSS_enableHighSidePinToggle (bool activeLow)
void PSS_enableInterrupt (void)
uint_fast8_t PSS_getHighSidePerformanceMode (void)
uint_fast8_t PSS_getHighSideVoltageTrigger (void)
uint32_t PSS_getInterruptStatus (void)
void PSS_registerInterrupt (void(∗intHandler)(void))
void PSS_setHighSidePerformanceMode (uint_fast8_t powerMode)
void PSS_setHighSideVoltageTrigger (uint_fast8_t triggerVoltage)
void PSS_unregisterInterrupt (void)
16.3.1 Detailed Description
The code for this module is contained in driverlib/pss.c, with driverlib/pss.h containing
the API declarations for use by applications.
Thu Jan 21 2016 12:34:41 AM
241
Power Supply System (PSS)
16.3.2 Function Documentation
16.3.2.1 void PSS_clearInterruptFlag ( void )
Clears power supply system interrupt source.
Returns
None.
16.3.2.2 void PSS_disableForcedDCDCOperation ( void )
Disables the "forced" mode of the DCDC regulator. In this mode, the fail safe mechanism that
disables the regulator to LDO mode when the supply voltage falls below the minimum supply
voltage required for DCDC operation is turned on.
Returns
None.
16.3.2.3 void PSS_disableHighSide ( void )
Disables high side voltage supervisor/monitor.
Returns
None.
16.3.2.4 void PSS_disableHighSideMonitor ( void )
Switches the high side of the power supply system to be a supervisor instead of a monitor
Returns
None.
16.3.2.5 void PSS_disableHighSidePinToggle ( void )
Disables output of the High Side interrupt flag on the device SVMHOUT pin
Returns
None.
16.3.2.6 void PSS_disableInterrupt ( void )
Disables the power supply system interrupt source.
Returns
None.
Thu Jan 21 2016 12:34:41 AM
242
Power Supply System (PSS)
16.3.2.7 void PSS_enableForcedDCDCOperation ( void )
Enables the "forced" mode of the DCDC regulator. In this mode, the fail safe mechanism that
disables the regulator to LDO mode when the supply voltage falls below the minimum supply
voltage required for DCDC operation is turned off.
Returns
None.
16.3.2.8 void PSS_enableHighSide ( void )
Enables high side voltage supervisor/monitor.
Returns
None.
16.3.2.9 void PSS_enableHighSideMonitor ( void )
Sets the high side voltage supervisor to monitor mode
Returns
None.
16.3.2.10 void PSS_enableHighSidePinToggle ( bool activeLow )
Enables output of the High Side interrupt flag on the device SVMHOUT pin
Parameters
activeLow
True if the signal should be logic low when SVSMHIFG is set. False if signal should be
high when SVSMHIFG is set.
Returns
None.
16.3.2.11 void PSS_enableInterrupt ( void )
Enables the power supply system interrupt source.
Returns
None.
Thu Jan 21 2016 12:34:41 AM
243
Power Supply System (PSS)
16.3.2.12 uint_fast8_t PSS_getHighSidePerformanceMode ( void )
Gets the performance mode of the high side voltage regulator. Refer to the user’s guide for
specific information about information about the different performance modes.
Returns
Performance mode of the voltage regulator
16.3.2.13 uint_fast8_t PSS_getHighSideVoltageTrigger ( void )
Returns the voltage level at which the high side of the device voltage regulator triggers a reset.
Returns
The voltage level that the high side voltage supervisor/monitor triggers a reset. This value is
represented as an unsigned eight bit integer where only the lowest three bits are most
significant. See PSS_setHighSideVoltageTrigger for information regarding the return value
16.3.2.14 uint32_t PSS_getInterruptStatus ( void )
Gets the current interrupt status.
Returns
The current interrupt status ( PSS_SVSMH )
16.3.2.15 void PSS_registerInterrupt ( void(∗)(void) intHandler )
Registers an interrupt handler for the power supply system interrupt.
Parameters
intHandler
is a pointer to the function to be called when the power supply system interrupt occurs.
This function registers the handler to be called when a power supply system interrupt occurs. This
function enables the global interrupt in the interrupt controller; specific PSS interrupts must be
enabled via PSS_enableInterrupt(). It is the interrupt handler’s responsibility to clear the interrupt
source via PSS_clearInterruptFlag().
See Also
Interrupt_registerInterrupt() for important information about registering interrupt handlers.
Returns
None.
References Interrupt_enableInterrupt(), and Interrupt_registerInterrupt().
Thu Jan 21 2016 12:34:41 AM
244
Power Supply System (PSS)
16.3.2.16 void PSS_setHighSidePerformanceMode ( uint_fast8_t powerMode )
Sets the performance mode of the high side regulator. Full performance mode allows for the best
response times while normal performance mode is optimized for the lowest possible current
consumption.
Thu Jan 21 2016 12:34:41 AM
245
Power Supply System (PSS)
Parameters
powerMode
is the performance mode to set. Valid values are one of the following:
PSS_FULL_PERFORMANCE_MODE,
PSS_NORMAL_PERFORMANCE_MODE
Returns
None.
16.3.2.17 void PSS_setHighSideVoltageTrigger ( uint_fast8_t triggerVoltage )
Sets the voltage level at which the high side of the device voltage regulator triggers a reset. This
value is represented as an unsigned eight bit integer where only the lowest three bits are most
significant.
Parameters
triggerVoltage
Voltage level in which high side supervisor/monitor triggers a reset. See the device specific
data sheet for details on these voltage levels.
Typical values will vary from part to part (so it is very important to check the SVSH section of the
data sheet. For reference only, the typical MSP432 101 values are listed below:
0 –> 1.57V
1 –> 1.62V
2 –> 1.83V
3 –> 2V
4 –> 2.25V
5 –> 2.4V
6 –> 2.6V
7 –> 2.8V
Returns
None.
16.3.2.18 void PSS_unregisterInterrupt ( void )
Unregisters the interrupt handler for the power supply system
This function unregisters the handler to be called when a power supply system interrupt occurs.
This function also masks off the interrupt in the interrupt controller so that the interrupt handler no
longer is called.
See Also
Interrupt_registerInterrupt() for important information about registering interrupt handlers.
Returns
None.
References Interrupt_disableInterrupt(), and Interrupt_unregisterInterrupt().
Thu Jan 21 2016 12:34:41 AM
246
Reference Module (REF_A)
17
Reference Module (REF_A)
Module Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .245
Programming Example . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .245
Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 246
17.1
Module Operation
The Internal Reference (REF_A) API provides a set of functions for using the MSPWare REF_A
modules. Functions are provided to setup and enable use of the Reference voltage, enable or
disable the internal temperature sensor, and view the status of the inner workings of the REF
module.
The reference module (REF_A) is responsible for generation of all critical reference voltages that
can be used by various analog peripherals in a given device. The heart of the reference system is
the bandgap from which all other references are derived by unity or non-inverting gain stages. The
REFGEN sub-system consists of the bandgap, the bandgap bias, and the non-inverting buffer
stage which generates the three primary voltage reference available in the system, namely 1.2 V,
1.45, 2.0 V, and 2.5 V. In addition, when enabled, a buffered bandgap voltage is available.
17.2
Programming Example
The DriverLib package contains a variety of different code examples that demonstrate the usage
of the REF_A module. These code examples are accessible under the examples/ folder of the
MSPWare release as well as through TI Resource Explorer if using Code Composer Studio.
These code examples provide a comprehensive list of use cases as well as practical applications
involving each module.
Below is a very brief code example showing how to enable the REF_A module for a 2.5v reference:
/* Setting reference voltage to 2.5 and enabling reference */
MAP_REF_A_setReferenceVoltage(REF_A_VREF2_5V);
MAP_REF_A_enableReferenceVoltage();
Thu Jan 21 2016 12:34:41 AM
247
Reference Module (REF_A)
17.3
Definitions
Functions
void REF_A_disableReferenceVoltage (void)
void REF_A_disableReferenceVoltageOutput (void)
void REF_A_disableTempSensor (void)
void REF_A_enableReferenceVoltage (void)
void REF_A_enableReferenceVoltageOutput (void)
void REF_A_enableTempSensor (void)
uint_fast8_t REF_A_getBandgapMode (void)
bool REF_A_getBufferedBandgapVoltageStatus (void)
bool REF_A_getVariableReferenceVoltageStatus (void)
bool REF_A_isBandgapActive (void)
bool REF_A_isRefGenActive (void)
bool REF_A_isRefGenBusy (void)
void REF_A_setBufferedBandgapVoltageOneTimeTrigger (void)
void REF_A_setReferenceVoltage (uint_fast8_t referenceVoltageSelect)
void REF_A_setReferenceVoltageOneTimeTrigger (void)
17.3.1 Detailed Description
The code for this module is contained in driverlib/ref_a.c, with driverlib/ref_a.h
containing the API declarations for use by applications.
Thu Jan 21 2016 12:34:41 AM
248
Reference Module (REF_A)
17.3.2 Function Documentation
17.3.2.1 void REF_A_disableReferenceVoltage ( void )
Disables the reference voltage.
This function is used to disable the generated reference voltage. Please note, if the
REF_A_isRefGenBusy() returns REF_A_BUSY, this function will have no effect.
Modified bits are REFON of REFCTL0 register.
Returns
none
17.3.2.2 void REF_A_disableReferenceVoltageOutput ( void )
Disables the reference voltage as an output to a pin.
This function is used to disables the reference voltage being generated to be given to an output
pin. Please note, if the REF_A_isRefGenBusy() returns REF_A_BUSY, this function will have no
effect.
Modified bits are REFOUT of REFCTL0 register.
Returns
none
17.3.2.3 void REF_A_disableTempSensor ( void )
Disables the internal temperature sensor to save power consumption.
This function is used to turn off the internal temperature sensor to save on power consumption.
The temperature sensor is enabled by default. Please note, that giving ADC12 module control
over the REF module, the state of the temperature sensor is dependent on the controls of the
ADC12 module. Please note, if the REF_A_isRefGenBusy() returns REF_A_BUSY, this function
will have no effect.
Modified bits are REFTCOFF of REFCTL0 register.
Returns
none
17.3.2.4 void REF_A_enableReferenceVoltage ( void )
Enables the reference voltage to be used by peripherals.
This function is used to enable the generated reference voltage to be used other peripherals or by
an output pin, if enabled. Please note, that giving ADC12 module control over the REF module,
the state of the reference voltage is dependent on the controls of the ADC12 module. Please note,
if the REF_A_isRefGenBusy() returns REF_A_BUSY, this function will have no effect.
Modified bits are REFON of REFCTL0 register.
Thu Jan 21 2016 12:34:41 AM
249
Reference Module (REF_A)
Returns
none
17.3.2.5 void REF_A_enableReferenceVoltageOutput ( void )
Outputs the reference voltage to an output pin.
This function is used to output the reference voltage being generated to an output pin. Please
note, the output pin is device specific. Please note, that giving ADC12 module control over the
REF module, the state of the reference voltage as an output to a pin is dependent on the controls
of the ADC12 module. Please note, if the REF_A_isRefGenBusy() returns REF_A_BUSY, this
function will have no effect.
Modified bits are REFOUT of REFCTL0 register.
Returns
none
17.3.2.6 void REF_A_enableTempSensor ( void )
Enables the internal temperature sensor.
This function is used to turn on the internal temperature sensor to use by other peripherals. The
temperature sensor is enabled by default. Please note, if the REF_A_isRefGenBusy() returns
REF_A_BUSY, this function will have no effect.
Modified bits are REFTCOFF of REFCTL0 register.
Returns
none
17.3.2.7 uint_fast8_t REF_A_getBandgapMode ( void )
Returns the bandgap mode of the REF module.
This function is used to return the bandgap mode of the REF module, requested by the
peripherals using the bandgap. If a peripheral requests static mode, then the bandgap mode will
be static for all modules, whereas if all of the peripherals using the bandgap request sample mode,
then that will be the mode returned. Sample mode allows the bandgap to be active only when
necessary to save on power consumption, static mode requires the bandgap to be active until no
peripherals are using it anymore.
Returns
The bandgap mode of the REF module:
REF_A_STATICMODE if the bandgap is operating in static mode
REF_A_SAMPLEMODE if the bandgap is operating in sample mode
Thu Jan 21 2016 12:34:41 AM
250
Reference Module (REF_A)
17.3.2.8 bool REF_A_getBufferedBandgapVoltageStatus ( void )
Returns the busy status of the reference generator in the REF module.
This function is used to return the buys status of the buffered bandgap voltage in the REF module.
If the ref. generator is on and ready to use, then the status will be seen as active.
Returns
true if the buffered bandgap voltage is ready to be used, false otherwise
17.3.2.9 bool REF_A_getVariableReferenceVoltageStatus ( void )
Returns the busy status of the variable reference voltage in the REF module.
This function is used to return the buys status of the variable reference voltage in the REF module.
If the ref. generator is on and ready to use, then the status will be seen as active.
Returns
true if the variable bandgap voltage is ready to be used, false otherwise
17.3.2.10 bool REF_A_isBandgapActive ( void )
Returns the active status of the bandgap in the REF module.
This function is used to return the active status of the bandgap in the REF module. If the bandgap
is in use by a peripheral, then the status will be seen as active.
Returns
true if the bandgap is being used, false otherwise
17.3.2.11 bool REF_A_isRefGenActive ( void )
Returns the active status of the reference generator in the REF module.
This function is used to return the active status of the reference generator in the REF module. If
the ref. generator is on and ready to use, then the status will be seen as active.
Returns
true if the reference generator is active, false otherwise.
17.3.2.12 bool REF_A_isRefGenBusy ( void )
Returns the busy status of the reference generator in the REF module.
This function is used to return the busy status of the reference generator in the REF module. If the
ref. generator is in use by a peripheral, then the status will be seen as busy.
Returns
true if the reference generator is being used, false otherwise.
Thu Jan 21 2016 12:34:41 AM
251
Reference Module (REF_A)
17.3.2.13 void REF_A_setBufferedBandgapVoltageOneTimeTrigger ( void )
Enables the one-time trigger of the buffered bandgap voltage.
Triggers the one-time generation of the buffered bandgap voltage. Once the buffered bandgap
voltage request is set, this bit is cleared by hardware
Modified bits are RefGOT of REFCTL0 register.
Returns
none
17.3.2.14 void REF_A_setReferenceVoltage ( uint_fast8_t referenceVoltageSelect )
Sets the reference voltage for the voltage generator.
Parameters
referenceVoltageSelect
is the desired voltage to generate for a reference voltage. Valid values are:
REF_A_VREF1_2V [Default]
REF_A_VREF1_45V
REF_A_VREF2_5V Modified bits are REFVSEL of REFCTL0 register.
This function sets the reference voltage generated by the voltage generator to be used by other
peripherals. This reference voltage will only be valid while the REF module is in control. Please
note, if the REF_A_isRefGenBusy() returns REF_BUSY, this function will have no effect.
Returns
none
17.3.2.15 void REF_A_setReferenceVoltageOneTimeTrigger ( void )
Enables the one-time trigger of the reference voltage.
Triggers the one-time generation of the variable reference voltage. Once the reference voltage
request is set, this bit is cleared by hardware
Modified bits are REFGENOT of REFCTL0 register.
Returns
none
Thu Jan 21 2016 12:34:41 AM
252
Reset Controller (ResetCtl)
18
Reset Controller (ResetCtl)
Module Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .251
Reset Sources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 251
Programming Example . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .251
Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 253
18.1
Module Operation
The DriverLib APIs for the MSP432 Reset Control are a set of power functions that enables
programmers to manipulate all aspects of a system reset. The user is able to initiate both hard and
soft resets as well as determine the cause of a prior system reset.
18.2
Reset Sources
Reset sources will vary from device to device (see the device specific datasheet for the reset
source mappings relevant to your device). The ResetCtl for DriverLib defines a set of generic reset
sources (such as RESET_SRC_0). In practice, it is a good idea to use a define statement to
match these to a specific reset source. For example, MSP432’s mapping could look something
similar to the following:
#define
#define
#define
#define
#define
#define
RESET_SYSTEM_SRC
RESET_WDTTIME_SRC
RESET_WDTPW_SRC
RESET_CS_SRC
RESET_PCM_SRC
RESET_SYS_SRC
RESET_SRC_0
RESET_SRC_1
RESET_SRC_2
RESET_SRC_3
RESET_SRC_14
RESET_SRC_15
By defining these extra set of macros, the user code that accesses the DriverLib ResetCtl APIs
are more legible. For example, when checking to see if a device was reset because of a CS
violation (such as a XTAL fault), the user could write code similar to the following:
if(ResetCtl_getSoftResetSource() == RESET_CS_SRC)
{
// Do reset handling here
}
18.3
Programming Example
Thu Jan 21 2016 12:34:41 AM
253
Reset Controller (ResetCtl)
The DriverLib package contains a variety of different code examples that demonstrate the usage
of the ResetCtl module. These code examples are accessible under the examples/ folder of the
MSPWare release as well as through TI Resource Explorer if using Code Composer Studio.
These code examples provide a comprehensive list of use cases as well as practical applications
involving each module.
Below is a very brief code example showing an ISR that initiates a software reset of the device.
The idea here is that a push button could cause a software initiated reset.
/* GPIO ISR */
void PORT1_IRQHandler(void)
{
uint32_t status;
status = MAP_GPIO_getEnabledInterruptStatus(GPIO_PORT_P1);
MAP_GPIO_clearInterruptFlag(GPIO_PORT_P1, status);
/* Initiated a hard reset */
if(status & GPIO_PIN1)
{
MAP_ResetCtl_initiateHardReset();
}
}
Thu Jan 21 2016 12:34:41 AM
254
Reset Controller (ResetCtl)
18.4
Definitions
Functions
void ResetCtl_clearHardResetSource (uint32_t mask)
void ResetCtl_clearPCMFlags (void)
void ResetCtl_clearPSSFlags (void)
void ResetCtl_clearSoftResetSource (uint32_t mask)
uint32_t ResetCtl_getHardResetSource (void)
uint32_t ResetCtl_getPCMSource (void)
uint32_t ResetCtl_getPSSSource (void)
uint32_t ResetCtl_getSoftResetSource (void)
void ResetCtl_initiateHardReset (void)
void ResetCtl_initiateHardResetWithSource (uint32_t source)
void ResetCtl_initiateSoftReset (void)
void ResetCtl_initiateSoftResetWithSource (uint32_t source)
18.4.1 Detailed Description
The code for this module is contained in driverlib/reset.c, with driverlib/reset.h
containing the API declarations for use by applications.
Thu Jan 21 2016 12:34:41 AM
255
Reset Controller (ResetCtl)
18.4.2 Function Documentation
18.4.2.1 void ResetCtl_clearHardResetSource ( uint32_t mask )
Clears the reset sources associated with at hard reset
Parameters
mask
- Bitwise OR of any of the following values:
RESET_SRC_0,
RESET_SRC_1,
RESET_SRC_2,
RESET_SRC_3,
RESET_SRC_4,
RESET_SRC_5,
RESET_SRC_6,
RESET_SRC_7,
RESET_SRC_8,
RESET_SRC_9,
RESET_SRC_10,
RESET_SRC_11,
RESET_SRC_12,
RESET_SRC_13,
RESET_SRC_14,
RESET_SRC_15
Returns
none
18.4.2.2 void ResetCtl_clearPCMFlags ( void )
Clears the corresponding PCM reset source flags
Returns
none
18.4.2.3 void ResetCtl_clearPSSFlags ( void )
Clears the PSS reset source flags
Returns
none
Thu Jan 21 2016 12:34:41 AM
256
Reset Controller (ResetCtl)
18.4.2.4 void ResetCtl_clearSoftResetSource ( uint32_t mask )
Clears the reset sources associated with at soft reset
Thu Jan 21 2016 12:34:41 AM
257
Reset Controller (ResetCtl)
Parameters
mask
- Bitwise OR of any of the following values:
RESET_SRC_0,
RESET_SRC_1,
RESET_SRC_2,
RESET_SRC_3,
RESET_SRC_4,
RESET_SRC_5,
RESET_SRC_6,
RESET_SRC_7,
RESET_SRC_8,
RESET_SRC_9,
RESET_SRC_10,
RESET_SRC_11,
RESET_SRC_12,
RESET_SRC_13,
RESET_SRC_14,
RESET_SRC_15
Returns
none
18.4.2.5 uint32_t ResetCtl_getHardResetSource ( void )
Retrieves previous hard reset sources
Returns
the bitwise or of previous reset sources. These sources must be cleared using the
ResetCtl_clearHardResetSource function to be cleared. Possible values include:
RESET_SRC_0,
RESET_SRC_1,
RESET_SRC_2,
RESET_SRC_3,
RESET_SRC_4,
RESET_SRC_5,
RESET_SRC_6,
RESET_SRC_7,
RESET_SRC_8,
RESET_SRC_9,
RESET_SRC_10,
RESET_SRC_11,
RESET_SRC_12,
Thu Jan 21 2016 12:34:41 AM
258
Reset Controller (ResetCtl)
RESET_SRC_13,
RESET_SRC_14,
RESET_SRC_15
18.4.2.6 uint32_t ResetCtl_getPCMSource ( void )
Indicates the last cause of a power-on reset (POR) due to PCM operation.
Returns
Bitwise OR of any of the following values:
RESET_LPM35,
RESET_LPM45
18.4.2.7 uint32_t ResetCtl_getPSSSource ( void )
Indicates the last cause of a power-on reset (POR) due to PSS operation. Note that the bits
returned from this function may be set in different combinations. When a cold power up occurs,
the value of all the values ORed together could be returned as a cold power up causes these
conditions.
Returns
Bitwise OR of any of the following values:
RESET_VCCDET,
RESET_SVSH_TRIP,
RESET_BGREF_BAD
18.4.2.8 uint32_t ResetCtl_getSoftResetSource ( void )
Retrieves previous soft reset sources
Returns
the bitwise or of previous reset sources. These sources must be cleared using the
ResetCtl_clearSoftResetSource function to be cleared. Possible values include:
RESET_SRC_0,
RESET_SRC_1,
RESET_SRC_2,
RESET_SRC_3,
RESET_SRC_4,
RESET_SRC_5,
RESET_SRC_6,
RESET_SRC_7,
RESET_SRC_8,
RESET_SRC_9,
RESET_SRC_10,
RESET_SRC_11,
Thu Jan 21 2016 12:34:41 AM
259
Reset Controller (ResetCtl)
RESET_SRC_12,
RESET_SRC_13,
RESET_SRC_14,
RESET_SRC_15
18.4.2.9 void ResetCtl_initiateHardReset ( void )
Initiates a hard system reset.
Returns
none
18.4.2.10 void ResetCtl_initiateHardResetWithSource ( uint32_t source )
Initiates a hard system reset with a particular source given. This source is generic and can be
assigned by the user.
Parameters
source
- Valid values are one the following values:
RESET_SRC_0,
RESET_SRC_1,
RESET_SRC_2,
RESET_SRC_3,
RESET_SRC_4,
RESET_SRC_5,
RESET_SRC_6,
RESET_SRC_7,
RESET_SRC_8,
RESET_SRC_9,
RESET_SRC_10,
RESET_SRC_11,
RESET_SRC_12,
RESET_SRC_13,
RESET_SRC_14,
RESET_SRC_15
Returns
none
Thu Jan 21 2016 12:34:41 AM
260
Reset Controller (ResetCtl)
18.4.2.11 void ResetCtl_initiateSoftReset ( void )
Initiates a soft system reset.
Returns
none
18.4.2.12 void ResetCtl_initiateSoftResetWithSource ( uint32_t source )
Initiates a soft system reset with a particular source given. This source is generic and can be
assigned by the user.
Parameters
source
Source of the reset. Valid values are:
RESET_SRC_0,
RESET_SRC_1,
RESET_SRC_2,
RESET_SRC_3,
RESET_SRC_4,
RESET_SRC_5,
RESET_SRC_6,
RESET_SRC_7,
RESET_SRC_8,
RESET_SRC_9,
RESET_SRC_10,
RESET_SRC_11,
RESET_SRC_12,
RESET_SRC_13,
RESET_SRC_14,
RESET_SRC_15
Returns
none
Thu Jan 21 2016 12:34:41 AM
261
Real Time Clock (RTC_C)
19
Real Time Clock (RTC_C)
Module Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .261
Programming Example . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .262
Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 263
19.1
Module Operation
The Real Time Clock (RTC_C) API provides a set of functions for using the MSPWare L RTC_C
modules. Functions are provided to calibrate the clock, initialize the RTC_C modules in Calendar
mode, and setup conditions for, and enable, interrupts for the RTC_C modules.
The RTC_C module provides the ability to keep track of the current time and date in calendar
mode.
The RTC_C module generates multiple interrupts. There are 2 interrupts that can be defined in
calendar mode, and 1 interrupt in counter mode for counter overflow, as well as an interrupt for
each prescaler.
Thu Jan 21 2016 12:34:41 AM
262
Real Time Clock (RTC_C)
19.2
Programming Example
The DriverLib package contains a variety of different code examples that demonstrate the usage
of the RTC_C module. These code examples are accessible under the examples/ folder of the
MSPWare release as well as through TI Resource Explorer if using Code Composer Studio.
These code examples provide a comprehensive list of use cases as well as practical applications
involving each module.
Below is a very brief code example showing how to configure the RTC_C module and create a
calendar event.
The following is the configuration structure that sets the date:
/* Time is November 12th 1955 10:03:00 PM */
const RTC_C_Calendar currentTime =
{
0x00,
0x03,
0x22,
0x12,
0x11,
0x1955
};
Next are the actual calls to DriverLib that configure the module:
/* Initializing RTC with current time as described in time in
* definitions section */
MAP_RTC_C_initCalendar(¤tTime, RTC_C_FORMAT_BCD);
/* Setup Calendar Alarm for 10:04pm (for the flux capacitor) */
MAP_RTC_C_setCalendarAlarm(0x04, 0x22, RTC_C_ALARMCONDITION_OFF,
RTC_C_ALARMCONDITION_OFF);
/* Specify an interrupt to assert every minute */
MAP_RTC_C_setCalendarEvent(RTC_C_CALENDAREVENT_MINUTECHANGE);
/* Enable interrupt for RTC Ready Status, which asserts when the RTC
* Calendar registers are ready to read.
* Also, enable interrupts for the Calendar alarm and Calendar event. */
MAP_RTC_C_clearInterruptFlag(
RTC_C_CLOCK_READ_READY_INTERRUPT | RTC_C_TIME_EVENT_INTERRUPT
| RTC_C_CLOCK_ALARM_INTERRUPT);
MAP_RTC_C_enableInterrupt(
RTC_C_CLOCK_READ_READY_INTERRUPT | RTC_C_TIME_EVENT_INTERRUPT
| RTC_C_CLOCK_ALARM_INTERRUPT);
/* Start RTC Clock */
MAP_RTC_C_startClock();
Thu Jan 21 2016 12:34:41 AM
263
Real Time Clock (RTC_C)
19.3
Definitions
Functions
void RTC_C_clearInterruptFlag (uint_fast8_t interruptFlagMask)
uint16_t RTC_C_convertBCDToBinary (uint16_t valueToConvert)
uint16_t RTC_C_convertBinaryToBCD (uint16_t valueToConvert)
void RTC_C_definePrescaleEvent (uint_fast8_t prescaleSelect, uint_fast8_t
prescaleEventDivider)
void RTC_C_disableInterrupt (uint8_t interruptMask)
void RTC_C_enableInterrupt (uint8_t interruptMask)
RTC_C_Calendar RTC_C_getCalendarTime (void)
uint_fast8_t RTC_C_getEnabledInterruptStatus (void)
uint_fast8_t RTC_C_getInterruptStatus (void)
uint_fast8_t RTC_C_getPrescaleValue (uint_fast8_t prescaleSelect)
void RTC_C_holdClock (void)
void RTC_C_initCalendar (const RTC_C_Calendar ∗calendarTime, uint_fast16_t
formatSelect)
void RTC_C_registerInterrupt (void(∗intHandler)(void))
void RTC_C_setCalendarAlarm (uint_fast8_t minutesAlarm, uint_fast8_t hoursAlarm,
uint_fast8_t dayOfWeekAlarm, uint_fast8_t dayOfmonthAlarm)
void RTC_C_setCalendarEvent (uint_fast16_t eventSelect)
void RTC_C_setCalibrationData (uint_fast8_t offsetDirection, uint_fast8_t offsetValue)
void RTC_C_setCalibrationFrequency (uint_fast16_t frequencySelect)
void RTC_C_setPrescaleValue (uint_fast8_t prescaleSelect, uint_fast8_t
prescaleCounterValue)
bool RTC_C_setTemperatureCompensation (uint_fast16_t offsetDirection, uint_fast8_t
offsetValue)
void RTC_C_startClock (void)
void RTC_C_unregisterInterrupt (void)
19.3.1 Detailed Description
The code for this module is contained in driverlib/rtc_c.c, with driverlib/rtc_c.h
containing the API declarations for use by applications.
Thu Jan 21 2016 12:34:41 AM
264
Real Time Clock (RTC_C)
19.3.2 Function Documentation
19.3.2.1 void RTC_C_clearInterruptFlag ( uint_fast8_t interruptFlagMask )
Clears selected RTC interrupt flags.
Parameters
interruptFlagMask
is a bit mask of the interrupt flags to be cleared. Mask Value is the logical OR of any of
the following
RTC_C_TIME_EVENT_INTERRUPT - asserts when counter overflows in counter
mode or when Calendar event condition defined by defineCalendarEvent() is met.
RTC_C_CLOCK_ALARM_INTERRUPT - asserts when alarm condition in Calendar
mode is met.
RTC_C_CLOCK_READ_READY_INTERRUPT - asserts when Calendar registers
are settled.
RTC_C_PRESCALE_TIMER0_INTERRUPT - asserts when Prescaler 0 event condition is met.
RTC_C_PRESCALE_TIMER1_INTERRUPT - asserts when Prescaler 1 event condition is met.
RTC_C_OSCILLATOR_FAULT_INTERRUPT - asserts if there is a problem with the
32kHz oscillator, while the RTC is running.
This function clears the RTC interrupt flag is cleared, so that it no longer asserts.
Returns
None
19.3.2.2 uint16_t RTC_C_convertBCDToBinary ( uint16_t valueToConvert )
Returns the given BCD value in Binary Format
Parameters
valueToConvert
is the raw value in BCD format to convert to Binary.
This function converts BCD values to Binary format.
Returns
The Binary version of the valueToConvert parameter.
19.3.2.3 uint16_t RTC_C_convertBinaryToBCD ( uint16_t valueToConvert )
Returns the given Binary value in BCD Format
Thu Jan 21 2016 12:34:41 AM
265
Real Time Clock (RTC_C)
Parameters
valueToConvert
is the raw value in Binary format to convert to BCD.
This function converts Binary values to BCD format.
Returns
The BCD version of the valueToConvert parameter.
19.3.2.4 void RTC_C_definePrescaleEvent ( uint_fast8_t prescaleSelect, uint_fast8_t
prescaleEventDivider )
Sets up an interrupt condition for the selected Prescaler.
Parameters
prescaleSelect
is the prescaler to define an interrupt for. Valid values are
RTC_C_PRESCALE_0
RTC_C_PRESCALE_1
prescaleEventDivider
is a divider to specify when an interrupt can occur based on the clock source of the selected prescaler. (Does not affect timer of the selected prescaler). Valid values are
RTC_C_PSEVENTDIVIDER_2 [Default]
RTC_C_PSEVENTDIVIDER_4
RTC_C_PSEVENTDIVIDER_8
RTC_C_PSEVENTDIVIDER_16
RTC_C_PSEVENTDIVIDER_32
RTC_C_PSEVENTDIVIDER_64
RTC_C_PSEVENTDIVIDER_128
RTC_C_PSEVENTDIVIDER_256
This function sets the condition for an interrupt to assert based on the individual prescalers.
Thu Jan 21 2016 12:34:41 AM
266
Real Time Clock (RTC_C)
Returns
None
19.3.2.5 void RTC_C_disableInterrupt ( uint8_t interruptMask )
Disables selected RTC interrupt sources.
Parameters
interruptMask
is a bit mask of the interrupts to disable. Mask Value is the logical OR of any of the
following
RTC_C_TIME_EVENT_INTERRUPT - asserts when counter overflows in counter
mode or when Calendar event condition defined by defineCalendarEvent() is met.
RTC_C_CLOCK_ALARM_INTERRUPT - asserts when alarm condition in Calendar
mode is met.
RTC_CLOCK_READ_READY_INTERRUPT - asserts when Calendar registers are
settled.
RTC_C_PRESCALE_TIMER0_INTERRUPT - asserts when Prescaler 0 event condition is met.
RTC_C_PRESCALE_TIMER1_INTERRUPT - asserts when Prescaler 1 event condition is met.
RTC_C_OSCILLATOR_FAULT_INTERRUPT - asserts if there is a problem with the
32kHz oscillator, while the RTC is running.
This function disables the selected RTC interrupt source. Only the sources that are enabled can
be reflected to the processor interrupt; disabled sources have no effect on the processor.
Returns
None
19.3.2.6 void RTC_C_enableInterrupt ( uint8_t interruptMask )
Enables selected RTC interrupt sources.
Thu Jan 21 2016 12:34:41 AM
267
Real Time Clock (RTC_C)
Parameters
interruptMask
is a bit mask of the interrupts to enable. Mask Value is the logical OR of any of the
following
RTC_C_TIME_EVENT_INTERRUPT - asserts when counter overflows in counter
mode or when Calendar event condition defined by defineCalendarEvent() is met.
RTC_C_CLOCK_ALARM_INTERRUPT - asserts when alarm condition in Calendar
mode is met.
RTC_C_CLOCK_READ_READY_INTERRUPT - asserts when Calendar registers
are settled.
RTC_C_PRESCALE_TIMER0_INTERRUPT - asserts when Prescaler 0 event condition is met.
RTC_C_PRESCALE_TIMER1_INTERRUPT - asserts when Prescaler 1 event condition is met.
RTC_C_OSCILLATOR_FAULT_INTERRUPT - asserts if there is a problem with the
32kHz oscillator, while the RTC is running.
This function enables the selected RTC interrupt source. Only the sources that are enabled can be
reflected to the processor interrupt; disabled sources have no effect on the processor.
Returns
None
19.3.2.7 RTC_C_Calendar RTC_C_getCalendarTime ( void )
Returns the Calendar Time stored in the Calendar registers of the RTC.
This function returns the current Calendar time in the form of a Calendar structure.
Returns
A Calendar structure containing the current time.
19.3.2.8 uint_fast8_t RTC_C_getEnabledInterruptStatus ( void )
Returns the status of the interrupts flags masked with the enabled interrupts. This function is
useful to call in ISRs to get a list of pending interrupts that are actually enabled and could have
caused the ISR.
Returns
A bit mask of the selected interrupt flag’s status. Mask Value is the logical OR of any of the
following
RTC_TIME_EVENT_INTERRUPT - asserts when counter overflows in counter mode or
when Calendar event condition defined by defineCalendarEvent() is met.
RTC_CLOCK_ALARM_INTERRUPT - asserts when alarm condition in Calendar mode
is met.
RTC_CLOCK_READ_READY_INTERRUPT - asserts when Calendar registers are
settled.
Thu Jan 21 2016 12:34:41 AM
268
Real Time Clock (RTC_C)
RTC_C_PRESCALE_TIMER0_INTERRUPT - asserts when Prescaler 0 event condition
is met.
RTC_C_PRESCALE_TIMER1_INTERRUPT - asserts when Prescaler 1 event condition
is met.
RTC_OSCILLATOR_FAULT_INTERRUPT - asserts if there is a problem with the 32kHz
oscillator, while the RTC is running.
References RTC_C_getInterruptStatus().
19.3.2.9 uint_fast8_t RTC_C_getInterruptStatus ( void )
Returns the status of the interrupts flags.
Returns
A bit mask of the selected interrupt flag’s status. Mask Value is the logical OR of any of the
following
RTC_C_TIME_EVENT_INTERRUPT - asserts when counter overflows in counter mode
or when Calendar event condition defined by defineCalendarEvent() is met.
RTC_C_CLOCK_ALARM_INTERRUPT - asserts when alarm condition in Calendar
mode is met.
RTC_C_CLOCK_READ_READY_INTERRUPT - asserts when Calendar registers are
settled.
RTC_C_PRESCALE_TIMER0_INTERRUPT - asserts when Prescaler 0 event condition
is met.
RTC_C_PRESCALE_TIMER1_INTERRUPT - asserts when Prescaler 1 event condition
is met.
RTC_C_OSCILLATOR_FAULT_INTERRUPT - asserts if there is a problem with the
32kHz oscillator, while the RTC is running.
Referenced by RTC_C_getEnabledInterruptStatus().
19.3.2.10 uint_fast8_t RTC_C_getPrescaleValue ( uint_fast8_t prescaleSelect )
Returns the selected Prescaler value.
Parameters
prescaleSelect
is the prescaler to obtain the value of. Valid values are
RTC_C_PRESCALE_0
RTC_C_PRESCALE_1
This function returns the value of the selected prescale counter register. The counter should be
held before reading. If in counter mode, the individual prescaler can be held, while in Calendar
mode the whole RTC must be held.
Returns
The value of the specified Prescaler count register
Thu Jan 21 2016 12:34:41 AM
269
Real Time Clock (RTC_C)
19.3.2.11 void RTC_C_holdClock ( void )
Holds the RTC.
This function sets the RTC main hold bit to disable RTC functionality.
Returns
None
Referenced by PCM_gotoLPM4().
19.3.2.12 void RTC_C_initCalendar ( const RTC_C_Calendar ∗ calendarTime,
uint_fast16_t formatSelect )
Initializes the settings to operate the RTC in Calendar mode.
Parameters
calendarTime
is the structure containing the values for the Calendar to be initialized to. Valid values
should be of type Calendar and should contain the following members and corresponding
values:
seconds between 0-59
minutes between 0-59
hours between 0-24
dayOfWeek between 0-6
dayOfmonth between 0-31
year between 0-4095
Note
Values beyond the ones specified may result in eradic behavior.
Parameters
formatSelect
is the format for the Calendar registers to use. Valid values are
RTC_FORMAT_BINARY [Default]
RTC_FORMAT_BCD
This function initializes the Calendar mode of the RTC module.
Returns
None
19.3.2.13 void RTC_C_registerInterrupt ( void(∗)(void) intHandler )
Registers an interrupt handler for the RTC interrupt.
Thu Jan 21 2016 12:34:41 AM
270
Real Time Clock (RTC_C)
Parameters
intHandler
is a pointer to the function to be called when the RTC interrupt occurs.
This function registers the handler to be called when a RTC interrupt occurs. This function enables
the global interrupt in the interrupt controller; specific AES interrupts must be enabled via
RTC_enableInterrupt(). It is the interrupt handler’s responsibility to clear the interrupt source via
RTC_clearInterruptFlag().
Returns
None.
References Interrupt_enableInterrupt(), and Interrupt_registerInterrupt().
19.3.2.14 void RTC_C_setCalendarAlarm ( uint_fast8_t minutesAlarm, uint_fast8_t
hoursAlarm, uint_fast8_t dayOfWeekAlarm, uint_fast8_t dayOfmonthAlarm )
Sets and Enables the desired Calendar Alarm settings.
Parameters
minutesAlarm
is the alarm condition for the minutes. Valid values are
An integer between 0-59, OR
RTC_C_ALARMCONDITION_OFF [Default]
hoursAlarm
is the alarm condition for the hours. Valid values are
An integer between 0-24, OR
RTC_C_ALARMCONDITION_OFF [Default]
dayOfWeekAlarm
is the alarm condition for the day of week. Valid values are
An integer between 0-6, OR
RTC_C_ALARMCONDITION_OFF [Default]
dayOfmonthAlarm
is the alarm condition for the day of the month. Valid values are
An integer between 0-31, OR
RTC_C_ALARMCONDITION_OFF [Default]
This function sets a Calendar interrupt condition to assert the RTCAIFG interrupt flag. The
condition is a logical and of all of the parameters. For example if the minutes and hours alarm is
set, then the interrupt will only assert when the minutes AND the hours change to the specified
setting. Use the RTC_ALARM_OFF for any alarm settings that should not be apart of the alarm
condition.
Returns
None
19.3.2.15 void RTC_C_setCalendarEvent ( uint_fast16_t eventSelect )
Sets a single specified Calendar interrupt condition.
Thu Jan 21 2016 12:34:41 AM
271
Real Time Clock (RTC_C)
Parameters
eventSelect
is the condition selected. Valid values are
RTC_C_CALENDAREVENT_MINUTECHANGE - assert interrupt on every minute
RTC_C_CALENDAREVENT_HOURCHANGE - assert interrupt on every hour
RTC_C_CALENDAREVENT_NOON - assert interrupt when hour is 12
RTC_C_CALENDAREVENT_MIDNIGHT - assert interrupt when hour is 0
This function sets a specified event to assert the RTCTEVIFG interrupt. This interrupt is
independent from the Calendar alarm interrupt.
Returns
None
19.3.2.16 void RTC_C_setCalibrationData ( uint_fast8_t offsetDirection, uint_fast8_t
offsetValue )
Sets the specified calibration for the RTC.
Parameters
offsetDirection
is the direction that the calibration offset will go. Valid values are
RTC_C_CALIBRATION_DOWN1PPM - calibrate at steps of -1
RTC_C_CALIBRATION_UP1PPM - calibrat at steps of +1
offsetValue
is the value that the offset will be a factor of; a valid value is any integer from 1-240.
This function sets the calibration offset to make the RTC as accurate as possible. The
offsetDirection can be either +1-ppm or -1-ppm, and the offsetValue should be from 1-240 and is
multiplied by the direction setting (i.e. +1-ppm ∗ 8 (offsetValue) = +8-ppm).
Returns
None
19.3.2.17 void RTC_C_setCalibrationFrequency ( uint_fast16_t frequencySelect )
Allows and Sets the frequency output to RTCLK pin for calibration measurement.
Parameters
frequencySelect
is the frequency output to RTCLK. Valid values are
RTC_C_CALIBRATIONFREQ_OFF - turn off calibration output [Default]
RTC_C_CALIBRATIONFREQ_512HZ - output signal at 512Hz for calibration
RTC_C_CALIBRATIONFREQ_256HZ - output signal at 256Hz for calibration
RTC_C_CALIBRATIONFREQ_1HZ - output signal at 1Hz for calibration
This function sets a frequency to measure at the RTCLK output pin. After testing the set
frequency, the calibration could be set accordingly.
Thu Jan 21 2016 12:34:41 AM
272
Real Time Clock (RTC_C)
Returns
None
19.3.2.18 void RTC_C_setPrescaleValue ( uint_fast8_t prescaleSelect, uint_fast8_t
prescaleCounterValue )
Sets the selected Prescaler value.
Parameters
prescaleSelect
is the prescaler to set the value for. Valid values are
RTC_C_PRESCALE_0
RTC_C_PRESCALE_1
prescaleCounterValue
is the specified value to set the prescaler to; a valid value is any integer from 0-255.
This function sets the prescale counter value. Before setting the prescale counter, it should be
held.
Returns
None
19.3.2.19 bool RTC_C_setTemperatureCompensation ( uint_fast16_t offsetDirection,
uint_fast8_t offsetValue )
Sets the specified temperature compensation for the RTC.
Parameters
offsetDirection
is the direction that the calibration offset will go. Valid values are
RTC_C_COMPENSATION_DOWN1PPM - calibrate at steps of -1
RTC_C_COMPENSATION_UP1PPM - calibrate at steps of +1
offsetValue
is the value that the offset will be a factor of; a value is any integer from 1-240.
This function sets the calibration offset to make the RTC as accurate as possible. The
offsetDirection can be either +1-ppm or -1-ppm, and the offsetValue should be from 1-240 and is
multiplied by the direction setting (i.e. +1-ppm ∗ 8 (offsetValue) = +8-ppm).
Returns
true if calibration was set, false if it could not be set
19.3.2.20 void RTC_C_startClock ( void )
Starts the RTC.
This function clears the RTC main hold bit to allow the RTC to function.
Thu Jan 21 2016 12:34:41 AM
273
Real Time Clock (RTC_C)
Returns
None
19.3.2.21 void RTC_C_unregisterInterrupt ( void )
Unregisters the interrupt handler for the RTC interrupt
This function unregisters the handler to be called when RTC interrupt occurs. This function also
masks off the interrupt in the interrupt controller so that the interrupt handler no longer is called.
See Also
Interrupt_registerInterrupt() for important information about registering interrupt handlers.
Returns
None.
References Interrupt_disableInterrupt(), and Interrupt_unregisterInterrupt().
Thu Jan 21 2016 12:34:41 AM
274
Serial Peripheral Interface (SPI)
20
Serial Peripheral Interface (SPI)
Module Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .275
Basic Operation Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 275
Programming Example . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .276
Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 277
20.1
Module Operation
The Serial Peripheral Interface Bus or SPI bus is a synchronous serial data link standard named
by Motorola that operates in full duplex mode. Devices communicate in master/slave mode where
the master device initiates the data frame. Note for simplicity, the module name EUSCI_A and
EUSCI_B have been omitted from the API names.
This library provides the API for handling a 3-wire SPI communication
The SPI module can be configured as either a master or a slave device.
The SPI module also includes a programmable bit rate clock divider and prescaler to generate the
output serial clock derived from the SSI module’s input clock.
20.2
Basic Operation Modes
To use the module as a master, the user must call SPI_masterInit() to configure the SPI Master.
This is followed by enabling the SPI module using SPI_enable(). The interrupts are then enabled
(if needed). It is recommended to enable the SPI module before enabling the interrupts. A data
transmit is then initiated using SPI_transmitData and then when the receive flag is set, the
received data is read using SPI_receiveData and this indicates that an RX/TX operation is
complete.
To use the module as a slave, initialization is done using SPI_initSlave and this is followed by
enabling the module using SPI_enableModule . Following this, the interrupts may be enabled as
needed. When the receive flag is set, data is first transmitted using SPI_transmitData and this is
followed by a data reception by SPI_receiveData .
Thu Jan 21 2016 12:34:41 AM
275
Serial Peripheral Interface (SPI)
20.3
Programming Example
The DriverLib package contains a variety of different code examples that demonstrate the usage
of the SPI module. These code examples are accessible under the examples/ folder of the
MSPWare release as well as through TI Resource Explorer if using Code Composer Studio.
These code examples provide a comprehensive list of use cases as well as practical applications
involving each module.
Below is a very brief code example showing how to configure the SPI module in 3wire master
mode.
In the code snippet below, the configuration settings for SPI in 3wire master mode can be seen:
/* SPI Master Configuration Parameter */
const eUSCI_SPI_MasterConfig spiMasterConfig =
{
EUSCI_B_SPI_CLOCKSOURCE_SMCLK,
// SMCLK Clock Source
3000000,
// SMCLK = DCO = 3MHZ
500000,
// SPICLK = 500khz
EUSCI_B_SPI_MSB_FIRST,
// MSB First
EUSCI_B_SPI_PHASE_DATA_CHANGED_ONFIRST_CAPTURED_ON_NEXT,
// Phase
EUSCI_B_SPI_CLOCKPOLARITY_INACTIVITY_HIGH, // High polarity
EUSCI_B_SPI_3PIN
// 3Wire SPI Mode
};
In this code snippet, the SPI module is configured and enabled for 3wire SPI operation using the
DriverLib APIs:
/* Selecting P1.5 P1.6 and P1.7 in SPI mode */
GPIO_setAsPeripheralModuleFunctionInputPin(GPIO_PORT_P1,
GPIO_PIN5 | GPIO_PIN6 | GPIO_PIN7, GPIO_PRIMARY_MODULE_FUNCTION);
/* Configuring SPI in 3wire master mode */
SPI_initMaster(EUSCI_B0_BASE, &spiMasterConfig);
/* Enable SPI module */
SPI_enableModule(EUSCI_B0_BASE);
/* Enabling interrupts */
SPI_enableInterrupt(EUSCI_B0_BASE, EUSCI_B_SPI_RECEIVE_INTERRUPT);
Interrupt_enableInterrupt(INT_EUSCIB0);
Interrupt_enableSleepOnIsrExit();
Thu Jan 21 2016 12:34:41 AM
276
Serial Peripheral Interface (SPI)
20.4
Definitions
Data Structures
struct _eUSCI_SPI_MasterConfig
struct _eUSCI_SPI_SlaveConfig
Functions
void EUSCI_A_SPI_changeClockPhasePolarity (uint32_t baseAddress, uint16_t clockPhase,
uint16_t clockPolarity)
void EUSCI_A_SPI_clearInterruptFlag (uint32_t baseAddress, uint8_t mask)
void EUSCI_A_SPI_disable (uint32_t baseAddress)
void EUSCI_A_SPI_disableInterrupt (uint32_t baseAddress, uint8_t mask)
void EUSCI_A_SPI_enable (uint32_t baseAddress)
void EUSCI_A_SPI_enableInterrupt (uint32_t baseAddress, uint8_t mask)
uint8_t EUSCI_A_SPI_getInterruptStatus (uint32_t baseAddress, uint8_t mask)
uint32_t EUSCI_A_SPI_getReceiveBufferAddressForDMA (uint32_t baseAddress)
uint32_t EUSCI_A_SPI_getTransmitBufferAddressForDMA (uint32_t baseAddress)
bool EUSCI_A_SPI_isBusy (uint32_t baseAddress)
void EUSCI_A_SPI_masterChangeClock (uint32_t baseAddress, uint32_t
clockSourceFrequency, uint32_t desiredSpiClock)
uint8_t EUSCI_A_SPI_receiveData (uint32_t baseAddress)
void EUSCI_A_SPI_select4PinFunctionality (uint32_t baseAddress, uint8_t
select4PinFunctionality)
bool EUSCI_A_SPI_slaveInit (uint32_t baseAddress, uint16_t msbFirst, uint16_t clockPhase,
uint16_t clockPolarity, uint16_t spiMode)
void EUSCI_A_SPI_transmitData (uint32_t baseAddress, uint8_t transmitData)
void EUSCI_B_SPI_changeClockPhasePolarity (uint32_t baseAddress, uint16_t clockPhase,
uint16_t clockPolarity)
void EUSCI_B_SPI_clearInterruptFlag (uint32_t baseAddress, uint8_t mask)
void EUSCI_B_SPI_disable (uint32_t baseAddress)
void EUSCI_B_SPI_disableInterrupt (uint32_t baseAddress, uint8_t mask)
void EUSCI_B_SPI_enable (uint32_t baseAddress)
void EUSCI_B_SPI_enableInterrupt (uint32_t baseAddress, uint8_t mask)
uint8_t EUSCI_B_SPI_getInterruptStatus (uint32_t baseAddress, uint8_t mask)
uint32_t EUSCI_B_SPI_getReceiveBufferAddressForDMA (uint32_t baseAddress)
uint32_t EUSCI_B_SPI_getTransmitBufferAddressForDMA (uint32_t baseAddress)
bool EUSCI_B_SPI_isBusy (uint32_t baseAddress)
void EUSCI_B_SPI_masterChangeClock (uint32_t baseAddress, uint32_t
clockSourceFrequency, uint32_t desiredSpiClock)
uint8_t EUSCI_B_SPI_receiveData (uint32_t baseAddress)
void EUSCI_B_SPI_select4PinFunctionality (uint32_t baseAddress, uint8_t
select4PinFunctionality)
bool EUSCI_B_SPI_slaveInit (uint32_t baseAddress, uint16_t msbFirst, uint16_t clockPhase,
uint16_t clockPolarity, uint16_t spiMode)
void EUSCI_B_SPI_transmitData (uint32_t baseAddress, uint8_t transmitData)
void SPI_changeClockPhasePolarity (uint32_t moduleInstance, uint_fast16_t clockPhase,
uint_fast16_t clockPolarity)
void SPI_changeMasterClock (uint32_t moduleInstance, uint32_t clockSourceFrequency,
uint32_t desiredSpiClock)
void SPI_clearInterruptFlag (uint32_t moduleInstance, uint_fast8_t mask)
void SPI_disableInterrupt (uint32_t moduleInstance, uint_fast8_t mask)
void SPI_disableModule (uint32_t moduleInstance)
Thu Jan 21 2016 12:34:41 AM
277
Serial Peripheral Interface (SPI)
void SPI_enableInterrupt (uint32_t moduleInstance, uint_fast8_t mask)
void SPI_enableModule (uint32_t moduleInstance)
uint_fast8_t SPI_getEnabledInterruptStatus (uint32_t moduleInstance)
uint_fast8_t SPI_getInterruptStatus (uint32_t moduleInstance, uint16_t mask)
uint32_t SPI_getReceiveBufferAddressForDMA (uint32_t moduleInstance)
uint32_t SPI_getTransmitBufferAddressForDMA (uint32_t moduleInstance)
bool SPI_initMaster (uint32_t moduleInstance, const eUSCI_SPI_MasterConfig ∗config)
bool SPI_initSlave (uint32_t moduleInstance, const eUSCI_SPI_SlaveConfig ∗config)
uint_fast8_t SPI_isBusy (uint32_t moduleInstance)
uint8_t SPI_receiveData (uint32_t moduleInstance)
void SPI_registerInterrupt (uint32_t moduleInstance, void(∗intHandler)(void))
void SPI_selectFourPinFunctionality (uint32_t moduleInstance, uint_fast8_t
select4PinFunctionality)
void SPI_transmitData (uint32_t moduleInstance, uint_fast8_t transmitData)
void SPI_unregisterInterrupt (uint32_t moduleInstance)
20.4.1 Detailed Description
The code for this module is contained in driverlib/spi.c, with driverlib/spi.h containing
the API declarations for use by applications.
Thu Jan 21 2016 12:34:41 AM
278
Serial Peripheral Interface (SPI)
20.4.2 Function Documentation
20.4.2.1 void EUSCI_A_SPI_changeClockPhasePolarity ( uint32_t baseAddress, uint16_t
clockPhase, uint16_t clockPolarity )
Changes the SPI colock phase and polarity. At the end of this function call, SPI module is left
enabled.
Parameters
baseAddress
clockPhase
is the base address of the EUSCI_A_SPI module.
is clock phase select. Valid values are:
EUSCI_A_SPI_PHASE_DATA_CHANGED_ONFIRST_CAPTURED_ON_NEXT
[Default]
EUSCI_A_SPI_PHASE_DATA_CAPTURED_ONFIRST_CHANGED_ON_NEXT
clockPolarity
is clock polarity select Valid values are:
EUSCI_A_SPI_CLOCKPOLARITY_INACTIVITY_HIGH
EUSCI_A_SPI_CLOCKPOLARITY_INACTIVITY_LOW [Default]
Modified bits are EUSCI_A_CTLW0_CKPL, EUSCI_A_CTLW0_CKPH and UCSWRST of
UCAxCTLW0 register.
Returns
None
Referenced by SPI_changeClockPhasePolarity().
20.4.2.2 void EUSCI_A_SPI_clearInterruptFlag ( uint32_t baseAddress, uint8_t mask )
Clears the selected SPI interrupt status flag.
Parameters
baseAddress
mask
is the base address of the EUSCI_A_SPI module.
is the masked interrupt flag to be cleared. Mask value is the logical OR of any of the
following:
EUSCI_A_SPI_TRANSMIT_INTERRUPT
EUSCI_A_SPI_RECEIVE_INTERRUPT
Modified bits of UCAxIFG register.
Thu Jan 21 2016 12:34:41 AM
279
Serial Peripheral Interface (SPI)
Returns
None
Referenced by SPI_clearInterruptFlag().
20.4.2.3 void EUSCI_A_SPI_disable ( uint32_t baseAddress )
Disables the SPI block.
This will disable operation of the SPI block.
Parameters
baseAddress
is the base address of the EUSCI_A_SPI module.
Modified bits are UCSWRST of UCAxCTLW0 register.
Returns
None
Referenced by SPI_disableModule().
20.4.2.4 void EUSCI_A_SPI_disableInterrupt ( uint32_t baseAddress, uint8_t mask )
Disables individual SPI interrupt sources.
Disables the indicated SPI interrupt sources. Only the sources that are enabled can be reflected to
the processor interrupt; disabled sources have no effect on the processor.
Parameters
baseAddress
mask
is the base address of the EUSCI_A_SPI module.
is the bit mask of the interrupt sources to be disabled. Mask value is the logical OR of any
of the following:
EUSCI_A_SPI_TRANSMIT_INTERRUPT
EUSCI_A_SPI_RECEIVE_INTERRUPT
Modified bits of UCAxIE register.
Returns
None
Referenced by SPI_disableInterrupt().
20.4.2.5 void EUSCI_A_SPI_enable ( uint32_t baseAddress )
Enables the SPI block.
This will enable operation of the SPI block.
Thu Jan 21 2016 12:34:41 AM
280
Serial Peripheral Interface (SPI)
Parameters
baseAddress
is the base address of the EUSCI_A_SPI module.
Modified bits are UCSWRST of UCAxCTLW0 register.
Returns
None
Referenced by SPI_enableModule().
20.4.2.6 void EUSCI_A_SPI_enableInterrupt ( uint32_t baseAddress, uint8_t mask )
Enables individual SPI interrupt sources.
Enables the indicated SPI interrupt sources. Only the sources that are enabled can be reflected to
the processor interrupt; disabled sources have no effect on the processor. Does not clear interrupt
flags.
Parameters
baseAddress
mask
is the base address of the EUSCI_A_SPI module.
is the bit mask of the interrupt sources to be enabled. Mask value is the logical OR of any
of the following:
EUSCI_A_SPI_TRANSMIT_INTERRUPT
EUSCI_A_SPI_RECEIVE_INTERRUPT
Modified bits of UCAxIFG register and bits of UCAxIE register.
Returns
None
Referenced by SPI_enableInterrupt().
20.4.2.7 uint8_t EUSCI_A_SPI_getInterruptStatus ( uint32_t baseAddress, uint8_t mask
)
Gets the current SPI interrupt status.
This returns the interrupt status for the SPI module based on which flag is passed.
Parameters
baseAddress
mask
is the base address of the EUSCI_A_SPI module.
is the masked interrupt flag status to be returned. Mask value is the logical OR of any of
the following:
EUSCI_A_SPI_TRANSMIT_INTERRUPT
EUSCI_A_SPI_RECEIVE_INTERRUPT
Thu Jan 21 2016 12:34:41 AM
281
Serial Peripheral Interface (SPI)
Returns
Logical OR of any of the following:
EUSCI_A_SPI_TRANSMIT_INTERRUPT
EUSCI_A_SPI_RECEIVE_INTERRUPT
indicating the status of the masked interrupts
Referenced by SPI_getInterruptStatus().
20.4.2.8 uint32_t EUSCI_A_SPI_getReceiveBufferAddressForDMA ( uint32_t
baseAddress )
Returns the address of the RX Buffer of the SPI for the DMA module.
Returns the address of the SPI RX Buffer. This can be used in conjunction with the DMA to store
the received data directly to memory.
Parameters
baseAddress
is the base address of the EUSCI_A_SPI module.
Returns
the address of the RX Buffer
Referenced by SPI_getReceiveBufferAddressForDMA().
20.4.2.9 uint32_t EUSCI_A_SPI_getTransmitBufferAddressForDMA ( uint32_t
baseAddress )
Returns the address of the TX Buffer of the SPI for the DMA module.
Returns the address of the SPI TX Buffer. This can be used in conjunction with the DMA to obtain
transmitted data directly from memory.
Parameters
baseAddress
is the base address of the EUSCI_A_SPI module.
Returns
the address of the TX Buffer
Referenced by SPI_getTransmitBufferAddressForDMA().
20.4.2.10 bool EUSCI_A_SPI_isBusy ( uint32_t baseAddress )
Indicates whether or not the SPI bus is busy.
This function returns an indication of whether or not the SPI bus is busy.This function checks the
status of the bus via UCBBUSY bit
Thu Jan 21 2016 12:34:41 AM
282
Serial Peripheral Interface (SPI)
Parameters
baseAddress
is the base address of the EUSCI_A_SPI module.
Returns
true if busy, false otherwise
Referenced by SPI_isBusy().
20.4.2.11 void EUSCI_A_SPI_masterChangeClock ( uint32_t baseAddress, uint32_t
clockSourceFrequency, uint32_t desiredSpiClock )
Initializes the SPI Master clock. At the end of this function call, SPI module is left enabled.
Parameters
baseAddress
clockSourceFrequency
desiredSpiClock
is the base address of the EUSCI_A_SPI module.
is the frequency of the slected clock source
is the desired clock rate for SPI communication
Modified bits are UCSWRST of UCAxCTLW0 register.
Returns
None
Referenced by SPI_changeMasterClock().
20.4.2.12 uint8_t EUSCI_A_SPI_receiveData ( uint32_t baseAddress )
Receives a byte that has been sent to the SPI Module.
This function reads a byte of data from the SPI receive data Register.
Parameters
baseAddress
is the base address of the EUSCI_A_SPI module.
Returns
Returns the byte received from by the SPI module, cast as an uint8_t.
Referenced by SPI_receiveData().
20.4.2.13 void EUSCI_A_SPI_select4PinFunctionality ( uint32_t baseAddress, uint8_t
select4PinFunctionality )
Selects 4Pin Functionality.
This function should be invoked only in 4-wire mode. Invoking this function has no effect in 3-wire
mode.
Thu Jan 21 2016 12:34:41 AM
283
Serial Peripheral Interface (SPI)
Parameters
baseAddress is the base address of the EUSCI_A_SPI module.
se- selects 4 pin functionality Valid values are:
lect4PinFunctionality
EUSCI_A_SPI_PREVENT_CONFLICTS_WITH_OTHER_MASTERS
EUSCI_A_SPI_ENABLE_SIGNAL_FOR_4WIRE_SLAVE
Modified bits are UCSTEM of UCAxCTLW0 register.
Returns
None
Referenced by SPI_selectFourPinFunctionality().
20.4.2.14 bool EUSCI_A_SPI_slaveInit ( uint32_t baseAddress, uint16_t msbFirst,
uint16_t clockPhase, uint16_t clockPolarity, uint16_t spiMode )
Initializes the SPI Slave block.
Upon successful initialization of the SPI slave block, this function will have initailized the slave
block, but the SPI Slave block still remains disabled and must be enabled with
EUSCI_A_SPI_enable()
Parameters
baseAddress
msbFirst
is the base address of the EUSCI_A_SPI Slave module.
controls the direction of the receive and transmit shift register. Valid values are:
EUSCI_A_SPI_MSB_FIRST
EUSCI_A_SPI_LSB_FIRST [Default]
clockPhase
is clock phase select. Valid values are:
EUSCI_A_SPI_PHASE_DATA_CHANGED_ONFIRST_CAPTURED_ON_NEXT
[Default]
EUSCI_A_SPI_PHASE_DATA_CAPTURED_ONFIRST_CHANGED_ON_NEXT
clockPolarity
is clock polarity select Valid values are:
EUSCI_A_SPI_CLOCKPOLARITY_INACTIVITY_HIGH
EUSCI_A_SPI_CLOCKPOLARITY_INACTIVITY_LOW [Default]
spiMode
is SPI mode select Valid values are:
EUSCI_A_SPI_3PIN
EUSCI_A_SPI_4PIN_UCxSTE_ACTIVE_HIGH
EUSCI_A_SPI_4PIN_UCxSTE_ACTIVE_LOW
Modified bits are EUSCI_A_CTLW0_MSB, EUSCI_A_CTLW0_MST,
EUSCI_A_CTLW0_SEVENBIT, EUSCI_A_CTLW0_CKPL, EUSCI_A_CTLW0_CKPH, UCMODE
and UCSWRST of UCAxCTLW0 register.
Thu Jan 21 2016 12:34:41 AM
284
Serial Peripheral Interface (SPI)
Returns
STATUS_SUCCESS
20.4.2.15 void EUSCI_A_SPI_transmitData ( uint32_t baseAddress, uint8_t transmitData )
Transmits a byte from the SPI Module.
This function will place the supplied data into SPI trasmit data register to start transmission.
Parameters
baseAddress
transmitData
is the base address of the EUSCI_A_SPI module.
data to be transmitted from the SPI module
Returns
None
Referenced by SPI_transmitData().
20.4.2.16 void EUSCI_B_SPI_changeClockPhasePolarity ( uint32_t baseAddress, uint16_t
clockPhase, uint16_t clockPolarity )
Changes the SPI colock phase and polarity. At the end of this function call, SPI module is left
enabled.
Parameters
baseAddress
clockPhase
is the base address of the EUSCI_B_SPI module.
is clock phase select. Valid values are:
EUSCI_B_SPI_PHASE_DATA_CHANGED_ONFIRST_CAPTURED_ON_NEXT
[Default]
EUSCI_B_SPI_PHASE_DATA_CAPTURED_ONFIRST_CHANGED_ON_NEXT
clockPolarity
is clock polarity select Valid values are:
EUSCI_B_SPI_CLOCKPOLARITY_INACTIVITY_HIGH
EUSCI_B_SPI_CLOCKPOLARITY_INACTIVITY_LOW [Default]
Modified bits are EUSCI_A_CTLW0_CKPL, EUSCI_A_CTLW0_CKPH and UCSWRST of
UCAxCTLW0 register.
Returns
None
Referenced by SPI_changeClockPhasePolarity().
20.4.2.17 void EUSCI_B_SPI_clearInterruptFlag ( uint32_t baseAddress, uint8_t mask )
Clears the selected SPI interrupt status flag.
Thu Jan 21 2016 12:34:41 AM
285
Serial Peripheral Interface (SPI)
Parameters
baseAddress
mask
is the base address of the EUSCI_B_SPI module.
is the masked interrupt flag to be cleared. Mask value is the logical OR of any of the
following:
EUSCI_B_SPI_TRANSMIT_INTERRUPT
EUSCI_B_SPI_RECEIVE_INTERRUPT
Modified bits of UCAxIFG register.
Returns
None
Referenced by SPI_clearInterruptFlag().
20.4.2.18 void EUSCI_B_SPI_disable ( uint32_t baseAddress )
Disables the SPI block.
This will disable operation of the SPI block.
Parameters
baseAddress
is the base address of the EUSCI_B_SPI module.
Modified bits are UCSWRST of UCBxCTLW0 register.
Returns
None
Referenced by SPI_disableModule().
20.4.2.19 void EUSCI_B_SPI_disableInterrupt ( uint32_t baseAddress, uint8_t mask )
Disables individual SPI interrupt sources.
Disables the indicated SPI interrupt sources. Only the sources that are enabled can be reflected to
the processor interrupt; disabled sources have no effect on the processor.
Parameters
baseAddress
mask
is the base address of the EUSCI_B_SPI module.
is the bit mask of the interrupt sources to be disabled. Mask value is the logical OR of any
of the following:
EUSCI_B_SPI_TRANSMIT_INTERRUPT
EUSCI_B_SPI_RECEIVE_INTERRUPT
Modified bits of UCAxIE register.
Returns
None
Referenced by SPI_disableInterrupt().
Thu Jan 21 2016 12:34:41 AM
286
Serial Peripheral Interface (SPI)
20.4.2.20 void EUSCI_B_SPI_enable ( uint32_t baseAddress )
Enables the SPI block.
This will enable operation of the SPI block.
Parameters
baseAddress
is the base address of the EUSCI_B_SPI module.
Modified bits are UCSWRST of UCBxCTLW0 register.
Returns
None
Referenced by SPI_enableModule().
20.4.2.21 void EUSCI_B_SPI_enableInterrupt ( uint32_t baseAddress, uint8_t mask )
Enables individual SPI interrupt sources.
Enables the indicated SPI interrupt sources. Only the sources that are enabled can be reflected to
the processor interrupt; disabled sources have no effect on the processor. Does not clear interrupt
flags.
Parameters
baseAddress
mask
is the base address of the EUSCI_B_SPI module.
is the bit mask of the interrupt sources to be enabled. Mask value is the logical OR of any
of the following:
EUSCI_B_SPI_TRANSMIT_INTERRUPT
EUSCI_B_SPI_RECEIVE_INTERRUPT
Modified bits of UCAxIFG register and bits of UCAxIE register.
Returns
None
Referenced by SPI_enableInterrupt().
20.4.2.22 uint8_t EUSCI_B_SPI_getInterruptStatus ( uint32_t baseAddress, uint8_t mask
)
Gets the current SPI interrupt status.
This returns the interrupt status for the SPI module based on which flag is passed.
Thu Jan 21 2016 12:34:41 AM
287
Serial Peripheral Interface (SPI)
Parameters
baseAddress
mask
is the base address of the EUSCI_B_SPI module.
is the masked interrupt flag status to be returned. Mask value is the logical OR of any of
the following:
EUSCI_B_SPI_TRANSMIT_INTERRUPT
EUSCI_B_SPI_RECEIVE_INTERRUPT
Returns
Logical OR of any of the following:
EUSCI_B_SPI_TRANSMIT_INTERRUPT
EUSCI_B_SPI_RECEIVE_INTERRUPT
indicating the status of the masked interrupts
Referenced by SPI_getInterruptStatus().
20.4.2.23 uint32_t EUSCI_B_SPI_getReceiveBufferAddressForDMA ( uint32_t
baseAddress )
Returns the address of the RX Buffer of the SPI for the DMA module.
Returns the address of the SPI RX Buffer. This can be used in conjunction with the DMA to store
the received data directly to memory.
Parameters
baseAddress
is the base address of the EUSCI_B_SPI module.
Returns
the address of the RX Buffer
Referenced by SPI_getReceiveBufferAddressForDMA().
20.4.2.24 uint32_t EUSCI_B_SPI_getTransmitBufferAddressForDMA ( uint32_t
baseAddress )
Returns the address of the TX Buffer of the SPI for the DMA module.
Returns the address of the SPI TX Buffer. This can be used in conjunction with the DMA to obtain
transmitted data directly from memory.
Parameters
baseAddress
is the base address of the EUSCI_B_SPI module.
Returns
the address of the TX Buffer
Referenced by SPI_getTransmitBufferAddressForDMA().
Thu Jan 21 2016 12:34:41 AM
288
Serial Peripheral Interface (SPI)
20.4.2.25 bool EUSCI_B_SPI_isBusy ( uint32_t baseAddress )
Indicates whether or not the SPI bus is busy.
This function returns an indication of whether or not the SPI bus is busy.This function checks the
status of the bus via UCBBUSY bit
Parameters
baseAddress
is the base address of the EUSCI_B_SPI module.
Returns
true if busy, false otherwise
Referenced by SPI_isBusy().
20.4.2.26 void EUSCI_B_SPI_masterChangeClock ( uint32_t baseAddress, uint32_t
clockSourceFrequency, uint32_t desiredSpiClock )
Initializes the SPI Master clock. At the end of this function call, SPI module is left enabled.
Parameters
baseAddress
clockSourceFrequency
desiredSpiClock
is the base address of the EUSCI_B_SPI module.
is the frequency of the slected clock source
is the desired clock rate for SPI communication
Modified bits are UCSWRST of UCAxCTLW0 register.
Returns
None
Referenced by SPI_changeMasterClock().
20.4.2.27 uint8_t EUSCI_B_SPI_receiveData ( uint32_t baseAddress )
Receives a byte that has been sent to the SPI Module.
This function reads a byte of data from the SPI receive data Register.
Parameters
baseAddress
Thu Jan 21 2016 12:34:41 AM
is the base address of the EUSCI_B_SPI module.
289
Serial Peripheral Interface (SPI)
Returns
Returns the byte received from by the SPI module, cast as an uint8_t.
Referenced by SPI_receiveData().
20.4.2.28 void EUSCI_B_SPI_select4PinFunctionality ( uint32_t baseAddress, uint8_t
select4PinFunctionality )
Selects 4Pin Functionality.
This function should be invoked only in 4-wire mode. Invoking this function has no effect in 3-wire
mode.
Parameters
baseAddress is the base address of the EUSCI_B_SPI module.
se- selects 4 pin functionality Valid values are:
lect4PinFunctionality
EUSCI_B_SPI_PREVENT_CONFLICTS_WITH_OTHER_MASTERS
EUSCI_B_SPI_ENABLE_SIGNAL_FOR_4WIRE_SLAVE
Modified bits are UCSTEM of UCAxCTLW0 register.
Returns
None
Referenced by SPI_selectFourPinFunctionality().
20.4.2.29 bool EUSCI_B_SPI_slaveInit ( uint32_t baseAddress, uint16_t msbFirst,
uint16_t clockPhase, uint16_t clockPolarity, uint16_t spiMode )
Initializes the SPI Slave block.
Upon successful initialization of the SPI slave block, this function will have initailized the slave
block, but the SPI Slave block still remains disabled and must be enabled with
EUSCI_B_SPI_enable()
Parameters
baseAddress
msbFirst
is the base address of the EUSCI_B_SPI Slave module.
controls the direction of the receive and transmit shift register. Valid values are:
EUSCI_B_SPI_MSB_FIRST
EUSCI_B_SPI_LSB_FIRST [Default]
Thu Jan 21 2016 12:34:41 AM
290
Serial Peripheral Interface (SPI)
clockPhase
is clock phase select. Valid values are:
EUSCI_B_SPI_PHASE_DATA_CHANGED_ONFIRST_CAPTURED_ON_NEXT
[Default]
EUSCI_B_SPI_PHASE_DATA_CAPTURED_ONFIRST_CHANGED_ON_NEXT
clockPolarity
is clock polarity select Valid values are:
EUSCI_B_SPI_CLOCKPOLARITY_INACTIVITY_HIGH
EUSCI_B_SPI_CLOCKPOLARITY_INACTIVITY_LOW [Default]
spiMode
is SPI mode select Valid values are:
EUSCI_B_SPI_3PIN
EUSCI_B_SPI_4PIN_UCxSTE_ACTIVE_HIGH
EUSCI_B_SPI_4PIN_UCxSTE_ACTIVE_LOW
Modified bits are EUSCI_A_CTLW0_MSB, EUSCI_A_CTLW0_MST,
EUSCI_A_CTLW0_SEVENBIT, EUSCI_A_CTLW0_CKPL, EUSCI_A_CTLW0_CKPH, UCMODE
and UCSWRST of UCAxCTLW0 register.
Returns
STATUS_SUCCESS
20.4.2.30 void EUSCI_B_SPI_transmitData ( uint32_t baseAddress, uint8_t transmitData )
Transmits a byte from the SPI Module.
This function will place the supplied data into SPI trasmit data register to start transmission.
Parameters
baseAddress
transmitData
is the base address of the EUSCI_B_SPI module.
data to be transmitted from the SPI module
Returns
None
Referenced by SPI_transmitData().
20.4.2.31 void SPI_changeClockPhasePolarity ( uint32_t moduleInstance, uint_fast16_t
clockPhase, uint_fast16_t clockPolarity )
Changes the SPI clock phase and polarity.At the end of this function call, SPI module is left
enabled.
Thu Jan 21 2016 12:34:41 AM
291
Serial Peripheral Interface (SPI)
Parameters
moduleInstance
is the instance of the eUSCI A/B module. Valid parameters vary from part to part, but can
include:
EUSCI_A0_BASE
EUSCI_A1_BASE
EUSCI_A2_BASE
EUSCI_A3_BASE
EUSCI_B0_BASE
EUSCI_B1_BASE
EUSCI_B2_BASE
EUSCI_B3_BASE
clockPhase
is clock phase select. Valid values are:
EUSCI_SPI_PHASE_DATA_CHANGED_ONFIRST_CAPTURED_ON_NEXT
[Default Value]
EUSCI_SPI_PHASE_DATA_CAPTURED_ONFIRST_CHANGED_ON_NEXT
clockPolarity
is clock polarity select. Valid values are:
EUSCI_SPI_CLOCKPOLARITY_INACTIVITY_HIGH
EUSCI_SPI_CLOCKPOLARITY_INACTIVITY_LOW [Default Value]
Modified bits are UCSWRST, UCCKPH, UCCKPL, UCSWRST bits of UCAxCTLW0
Returns
None
References EUSCI_A_SPI_changeClockPhasePolarity(), and
EUSCI_B_SPI_changeClockPhasePolarity().
20.4.2.32 void SPI_changeMasterClock ( uint32_t moduleInstance, uint32_t
clockSourceFrequency, uint32_t desiredSpiClock )
Initializes the SPI Master clock.At the end of this function call, SPI module is left enabled.
Thu Jan 21 2016 12:34:41 AM
292
Serial Peripheral Interface (SPI)
Parameters
moduleInstance
is the instance of the eUSCI A/B module. Valid parameters vary from part to part, but can
include:
EUSCI_A0_BASE
EUSCI_A1_BASE
EUSCI_A2_BASE
EUSCI_A3_BASE
EUSCI_B0_BASE
EUSCI_B1_BASE
EUSCI_B2_BASE
EUSCI_B3_BASE
clockSourceFrequency
desiredSpiClock
is the frequency of the selected clock source
is the desired clock rate for SPI communication.
Modified bits are UCSWRST bit of UCAxCTLW0 register and UCAxBRW register
Returns
None
References EUSCI_A_SPI_masterChangeClock(), and EUSCI_B_SPI_masterChangeClock().
20.4.2.33 void SPI_clearInterruptFlag ( uint32_t moduleInstance, uint_fast8_t mask )
Clears the selected SPI interrupt status flag.
Parameters
moduleInstance
is the instance of the eUSCI A/B module. Valid parameters vary from part to part, but can
include:
EUSCI_A0_BASE
EUSCI_A1_BASE
EUSCI_A2_BASE
EUSCI_A3_BASE
EUSCI_B0_BASE
EUSCI_B1_BASE
EUSCI_B2_BASE
EUSCI_B3_BASE
Thu Jan 21 2016 12:34:41 AM
293
Serial Peripheral Interface (SPI)
mask
is the masked interrupt flag to be cleared.
The mask parameter is the logical OR of any of the following:
EUSCI_SPI_RECEIVE_INTERRUPT -Receive interrupt
EUSCI_SPI_TRANSMIT_INTERRUPT - Transmit interrupt Modified registers are UCAxIFG.
Returns
None
References EUSCI_A_SPI_clearInterruptFlag(), and EUSCI_B_SPI_clearInterruptFlag().
20.4.2.34 void SPI_disableInterrupt ( uint32_t moduleInstance, uint_fast8_t mask )
Disables individual SPI interrupt sources.
Parameters
moduleInstance
is the instance of the eUSCI A/B module. Valid parameters vary from part to part, but can
include:
EUSCI_A0_BASE
EUSCI_A1_BASE
EUSCI_A2_BASE
EUSCI_A3_BASE
EUSCI_B0_BASE
EUSCI_B1_BASE
EUSCI_B2_BASE
EUSCI_B3_BASE
mask
is the bit mask of the interrupt sources to be disabled.
Disables the indicated SPI interrupt sources. Only the sources that are enabled can be reflected to
the processor interrupt; disabled sources have no effect on the processor.
The mask parameter is the logical OR of any of the following:
EUSCI_SPI_RECEIVE_INTERRUPT Receive interrupt
EUSCI_SPI_TRANSMIT_INTERRUPT Transmit interrupt
Modified register is UCAxIE
Returns
None.
References EUSCI_A_SPI_disableInterrupt(), and EUSCI_B_SPI_disableInterrupt().
20.4.2.35 void SPI_disableModule ( uint32_t moduleInstance )
Disables the SPI block.
Thu Jan 21 2016 12:34:41 AM
294
Serial Peripheral Interface (SPI)
Parameters
moduleInstance
is the instance of the eUSCI A/B module. Valid parameters vary from part to part, but can
include:
EUSCI_A0_BASE
EUSCI_A1_BASE
EUSCI_A2_BASE
EUSCI_A3_BASE
EUSCI_B0_BASE
EUSCI_B1_BASE
EUSCI_B2_BASE
EUSCI_B3_BASE
This will disable operation of the SPI block.
Modified bits are UCSWRST bit of UCAxCTLW0 register.
Returns
None.
References EUSCI_A_SPI_disable(), and EUSCI_B_SPI_disable().
20.4.2.36 void SPI_enableInterrupt ( uint32_t moduleInstance, uint_fast8_t mask )
Enables individual SPI interrupt sources.
Parameters
moduleInstance
is the instance of the eUSCI A/B module. Valid parameters vary from part to part, but can
include:
EUSCI_A0_BASE
EUSCI_A1_BASE
EUSCI_A2_BASE
EUSCI_A3_BASE
EUSCI_B0_BASE
EUSCI_B1_BASE
EUSCI_B2_BASE
EUSCI_B3_BASE
Thu Jan 21 2016 12:34:41 AM
295
Serial Peripheral Interface (SPI)
mask
is the bit mask of the interrupt sources to be enabled.
Enables the indicated SPI interrupt sources. Only the sources that are enabled can be reflected to
the processor interrupt; disabled sources have no effect on the processor.
The mask parameter is the logical OR of any of the following:
EUSCI_SPI_RECEIVE_INTERRUPT Receive interrupt
EUSCI_SPI_TRANSMIT_INTERRUPT Transmit interrupt
Modified registers are UCAxIFG and UCAxIE
Returns
None.
References EUSCI_A_SPI_enableInterrupt(), and EUSCI_B_SPI_enableInterrupt().
20.4.2.37 void SPI_enableModule ( uint32_t moduleInstance )
Enables the SPI block.
Parameters
moduleInstance
is the instance of the eUSCI A/B module. Valid parameters vary from part to part, but can
include:
EUSCI_A0_BASE
EUSCI_A1_BASE
EUSCI_A2_BASE
EUSCI_A3_BASE
EUSCI_B0_BASE
EUSCI_B1_BASE
EUSCI_B2_BASE
EUSCI_B3_BASE
This will enable operation of the SPI block. Modified bits are UCSWRST bit of UCAxCTLW0
register.
Returns
None.
References EUSCI_A_SPI_enable(), and EUSCI_B_SPI_enable().
20.4.2.38 uint_fast8_t SPI_getEnabledInterruptStatus ( uint32_t moduleInstance )
Gets the current SPI interrupt status masked with the enabled interrupts. This function is useful to
call in ISRs to get a list of pending interrupts that are actually enabled and could have caused the
ISR.
Thu Jan 21 2016 12:34:41 AM
296
Serial Peripheral Interface (SPI)
Parameters
moduleInstance
is the instance of the eUSCI A/B module. Valid parameters vary from part to part, but can
include:
EUSCI_A0_BASE
EUSCI_A1_BASE
EUSCI_A2_BASE
EUSCI_A3_BASE
EUSCI_B0_BASE
EUSCI_B1_BASE
EUSCI_B2_BASE
EUSCI_B3_BASE
Modified registers are UCAxIFG.
Returns
The current interrupt status as the mask of the set flags Mask parameter can be either any of
the following selection:
EUSCI_SPI_RECEIVE_INTERRUPT -Receive interrupt
EUSCI_SPI_TRANSMIT_INTERRUPT - Transmit interrupt
References SPI_getInterruptStatus().
20.4.2.39 uint_fast8_t SPI_getInterruptStatus ( uint32_t moduleInstance, uint16_t mask )
Gets the current SPI interrupt status.
Parameters
moduleInstance
is the instance of the eUSCI A/B module. Valid parameters vary from part to part, but can
include:
EUSCI_A0_BASE
EUSCI_A1_BASE
EUSCI_A2_BASE
EUSCI_A3_BASE
EUSCI_B0_BASE
EUSCI_B1_BASE
EUSCI_B2_BASE
EUSCI_B3_BASE
mask
Mask of interrupt to filter. This can include:
EUSCI_SPI_RECEIVE_INTERRUPT -Receive interrupt
EUSCI_SPI_TRANSMIT_INTERRUPT - Transmit interrupt
Modified registers are UCAxIFG.
Thu Jan 21 2016 12:34:41 AM
297
Serial Peripheral Interface (SPI)
Returns
The current interrupt status as the mask of the set flags Mask parameter can be either any of
the following selection:
EUSCI_SPI_RECEIVE_INTERRUPT -Receive interrupt
EUSCI_SPI_TRANSMIT_INTERRUPT - Transmit interrupt
References EUSCI_A_SPI_getInterruptStatus(), and EUSCI_B_SPI_getInterruptStatus().
Referenced by SPI_getEnabledInterruptStatus().
20.4.2.40 uint32_t SPI_getReceiveBufferAddressForDMA ( uint32_t moduleInstance )
Returns the address of the RX Buffer of the SPI for the DMA module.
Parameters
moduleInstance
is the instance of the eUSCI A/B module. Valid parameters vary from part to part, but can
include:
EUSCI_A0_BASE
EUSCI_A1_BASE
EUSCI_A2_BASE
EUSCI_A3_BASE
EUSCI_B0_BASE
EUSCI_B1_BASE
EUSCI_B2_BASE
EUSCI_B3_BASE
Returns the address of the SPI RX Buffer. This can be used in conjunction with the DMA to store
the received data directly to memory.
Thu Jan 21 2016 12:34:41 AM
298
Serial Peripheral Interface (SPI)
Returns
NONE
References EUSCI_A_SPI_getReceiveBufferAddressForDMA(), and
EUSCI_B_SPI_getReceiveBufferAddressForDMA().
20.4.2.41 uint32_t SPI_getTransmitBufferAddressForDMA ( uint32_t moduleInstance )
Returns the address of the TX Buffer of the SPI for the DMA module.
Parameters
moduleInstance
is the instance of the eUSCI A/B module. Valid parameters vary from part to part, but can
include:
EUSCI_A0_BASE
EUSCI_A1_BASE
EUSCI_A2_BASE
EUSCI_A3_BASE
EUSCI_B0_BASE
EUSCI_B1_BASE
EUSCI_B2_BASE
EUSCI_B3_BASE
Returns the address of the SPI TX Buffer. This can be used in conjunction with the DMA to obtain
transmitted data directly from memory.
Returns
NONE
References EUSCI_A_SPI_getTransmitBufferAddressForDMA(), and
EUSCI_B_SPI_getTransmitBufferAddressForDMA().
20.4.2.42 bool SPI_initMaster ( uint32_t moduleInstance, const eUSCI_SPI_MasterConfig
∗ config )
Initializes the SPI Master block.
Thu Jan 21 2016 12:34:41 AM
299
Serial Peripheral Interface (SPI)
Parameters
moduleInstance
is the instance of the eUSCI A/B module. Valid parameters vary from part to part, but can
include:
EUSCI_A0_BASE
EUSCI_A1_BASE
EUSCI_A2_BASE
EUSCI_A3_BASE
EUSCI_B0_BASE
EUSCI_B1_BASE
EUSCI_B2_BASE
EUSCI_B3_BASE
config
Configuration structure for SPI master mode
Configuration options for eUSCI_SPI_MasterConfig structure.
Parameters
selectClockSource
selects clock source. Valid values are
EUSCI_SPI_CLOCKSOURCE_ACLK
EUSCI_SPI_CLOCKSOURCE_SMCLK
clockSourceFrequency
desiredSpiClock
msbFirst
is the frequency of the selected clock source
is the desired clock rate for SPI communication
controls the direction of the receive and transmit shift register. Valid values are
EUSCI_SPI_MSB_FIRST
EUSCI_SPI_LSB_FIRST [Default Value]
clockPhase
is clock phase select. Valid values are
EUSCI_SPI_PHASE_DATA_CHANGED_ONFIRST_CAPTURED_ON_NEXT
[Default Value]
EUSCI_SPI_PHASE_DATA_CAPTURED_ONFIRST_CHANGED_ON_NEXT
clockPolarity
is clock polarity select. Valid values are
EUSCI_SPI_CLOCKPOLARITY_INACTIVITY_HIGH
EUSCI_SPI_CLOCKPOLARITY_INACTIVITY_LOW [Default Value]
Thu Jan 21 2016 12:34:41 AM
300
Serial Peripheral Interface (SPI)
spiMode
is SPI mode select. Valid values are
EUSCI_SPI_3PIN [Default Value]
EUSCI_SPI_4PIN_UCxSTE_ACTIVE_HIGH
EUSCI_SPI_4PIN_UCxSTE_ACTIVE_LOW Upon successful initialization of the SPI
master block, this function will have set the bus speed for the master, but the SPI
Master block still remains disabled and must be enabled with SPI_enableModule()
Modified bits are UCCKPH, UCCKPL, UC7BIT, UCMSB, UCSSELx, UCSWRST bits of
UCAxCTLW0 register
Returns
true
20.4.2.43 bool SPI_initSlave ( uint32_t moduleInstance, const eUSCI_SPI_SlaveConfig ∗
config )
Initializes the SPI Slave block.
Parameters
moduleInstance
is the instance of the eUSCI A/B module. Valid parameters vary from part to part, but can
include:
EUSCI_A0_BASE
EUSCI_A1_BASE
EUSCI_A2_BASE
EUSCI_A3_BASE
EUSCI_B0_BASE
EUSCI_B1_BASE
EUSCI_B2_BASE
EUSCI_B3_BASE
Thu Jan 21 2016 12:34:41 AM
301
Serial Peripheral Interface (SPI)
config
Configuration structure for SPI slave mode
Configuration options for eUSCI_SPI_SlaveConfig structure.
Parameters
msbFirst
controls the direction of the receive and transmit shift register. Valid values are
EUSCI_SPI_MSB_FIRST
EUSCI_SPI_LSB_FIRST [Default Value]
clockPhase
is clock phase select. Valid values are
EUSCI_SPI_PHASE_DATA_CHANGED_ONFIRST_CAPTURED_ON_NEXT
[Default Value]
EUSCI_SPI_PHASE_DATA_CAPTURED_ONFIRST_CHANGED_ON_NEXT
clockPolarity
is clock polarity select. Valid values are
EUSCI_SPI_CLOCKPOLARITY_INACTIVITY_HIGH
EUSCI_SPI_CLOCKPOLARITY_INACTIVITY_LOW [Default Value]
spiMode
is SPI mode select. Valid values are
EUSCI_SPI_3PIN [Default Value]
EUSCI_SPI_4PIN_UCxSTE_ACTIVE_HIGH
EUSCI_SPI_4PIN_UCxSTE_ACTIVE_LOW Upon successful initialization of the SPI
slave block, this function will have initialized the slave block, but the SPI Slave block
still remains disabled and must be enabled with SPI_enableModule()
Modified bits are UCMSB, UC7BIT, UCMST, UCCKPL, UCCKPH, UCMODE, UCSWRST bits of
UCAxCTLW0
Returns
true
20.4.2.44 uint_fast8_t SPI_isBusy ( uint32_t moduleInstance )
Indicates whether or not the SPI bus is busy.
Thu Jan 21 2016 12:34:41 AM
302
Serial Peripheral Interface (SPI)
Parameters
moduleInstance
is the instance of the eUSCI A/B module. Valid parameters vary from part to part, but can
include:
EUSCI_A0_BASE
EUSCI_A1_BASE
EUSCI_A2_BASE
EUSCI_A3_BASE
EUSCI_B0_BASE
EUSCI_B1_BASE
EUSCI_B2_BASE
EUSCI_B3_BASE
This function returns an indication of whether or not the SPI bus is busy.This function checks the
status of the bus via UCBBUSY bit
Returns
EUSCI_SPI_BUSY if the SPI module transmitting or receiving is busy; otherwise, returns
EUSCI_SPI_NOT_BUSY.
References EUSCI_A_SPI_isBusy(), and EUSCI_B_SPI_isBusy().
20.4.2.45 uint8_t SPI_receiveData ( uint32_t moduleInstance )
Receives a byte that has been sent to the SPI Module.
Parameters
moduleInstance
is the instance of the eUSCI A/B module. Valid parameters vary from part to part, but can
include:
EUSCI_A0_BASE
EUSCI_A1_BASE
EUSCI_A2_BASE
EUSCI_A3_BASE
EUSCI_B0_BASE
EUSCI_B1_BASE
EUSCI_B2_BASE
EUSCI_B3_BASE
This function reads a byte of data from the SPI receive data Register.
Returns
Returns the byte received from by the SPI module, cast as an uint8_t.
References EUSCI_A_SPI_receiveData(), and EUSCI_B_SPI_receiveData().
Thu Jan 21 2016 12:34:41 AM
303
Serial Peripheral Interface (SPI)
20.4.2.46 void SPI_registerInterrupt ( uint32_t moduleInstance, void(∗)(void) intHandler )
Registers an interrupt handler for the timer capture compare interrupt.
Thu Jan 21 2016 12:34:41 AM
304
Serial Peripheral Interface (SPI)
Parameters
moduleInstance
is the instance of the eUSCI (SPI) module. Valid parameters vary from part to part, but
can include:
EUSCI_A0_BASE
EUSCI_A1_BASE
EUSCI_A2_BASE
EUSCI_A3_BASE
EUSCI_B0_BASE
EUSCI_B1_BASE
EUSCI_B2_BASE
EUSCI_B3_BASE It is important to note that for eUSCI modules, only "B" modules
such as EUSCI_B0 can be used. "A" modules such as EUSCI_A0 do not support
the I2C mode.
intHandler
is a pointer to the function to be called when the timer capture compare interrupt occurs.
This function registers the handler to be called when a timer interrupt occurs. This function
enables the global interrupt in the interrupt controller; specific SPI interrupts must be enabled via
SPI_enableInterrupt(). It is the interrupt handler’s responsibility to clear the interrupt source via
SPI_clearInterruptFlag().
Returns
None.
References Interrupt_enableInterrupt(), and Interrupt_registerInterrupt().
20.4.2.47 void SPI_selectFourPinFunctionality ( uint32_t moduleInstance, uint_fast8_t
select4PinFunctionality )
Selects 4Pin Functionality
Thu Jan 21 2016 12:34:41 AM
305
Serial Peripheral Interface (SPI)
Parameters
moduleInstance
is the instance of the eUSCI A/B module. Valid parameters vary from part to part, but can
include:
EUSCI_A0_BASE
EUSCI_A1_BASE
EUSCI_A2_BASE
EUSCI_A3_BASE
EUSCI_B0_BASE
EUSCI_B1_BASE
EUSCI_B2_BASE
EUSCI_B3_BASE
se- selects Clock source. Valid values are
lect4PinFunctionality
EUSCI_SPI_PREVENT_CONFLICTS_WITH_OTHER_MASTERS
EUSCI_SPI_ENABLE_SIGNAL_FOR_4WIRE_SLAVE This function should be invoked only in 4-wire mode. Invoking this function has no effect in 3-wire mode.
Modified bits are UCSTEM bit of UCAxCTLW0 register
Returns
true
References EUSCI_A_SPI_select4PinFunctionality(), and
EUSCI_B_SPI_select4PinFunctionality().
20.4.2.48 void SPI_transmitData ( uint32_t moduleInstance, uint_fast8_t transmitData )
Transmits a byte from the SPI Module.
Parameters
moduleInstance
is the instance of the eUSCI A/B module. Valid parameters vary from part to part, but can
include:
EUSCI_A0_BASE
EUSCI_A1_BASE
EUSCI_A2_BASE
EUSCI_A3_BASE
EUSCI_B0_BASE
EUSCI_B1_BASE
EUSCI_B2_BASE
EUSCI_B3_BASE
Thu Jan 21 2016 12:34:41 AM
306
Serial Peripheral Interface (SPI)
transmitData
data to be transmitted from the SPI module
This function will place the supplied data into SPI transmit data register to start transmission
Modified register is UCAxTXBUF
Returns
None.
References EUSCI_A_SPI_transmitData(), and EUSCI_B_SPI_transmitData().
20.4.2.49 void SPI_unregisterInterrupt ( uint32_t moduleInstance )
Unregisters the interrupt handler for the timer
Parameters
moduleInstance
is the instance of the eUSCI A/B module. Valid parameters vary from part to part, but can
include:
EUSCI_A0_BASE
EUSCI_A1_BASE
EUSCI_A2_BASE
EUSCI_A3_BASE
EUSCI_B0_BASE
EUSCI_B1_BASE
EUSCI_B2_BASE
EUSCI_B3_BASE
This function unregisters the handler to be called when timer interrupt occurs. This function also
masks off the interrupt in the interrupt controller so that the interrupt handler no longer is called.
See Also
Interrupt_registerInterrupt() for important information about registering interrupt handlers.
Returns
None.
References Interrupt_disableInterrupt(), and Interrupt_unregisterInterrupt().
Thu Jan 21 2016 12:34:41 AM
307
System Control Module (SysCtl)
21
System Control Module (SysCtl)
Module Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .307
Programming Example . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .307
Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 308
21.1
Module Operation
The SysCtl module is a conglomeration of miscellaneous system control modules that do not fit
into any specific hardware peripheral.
Some of the functionalities of the SysCtl module include:
Configure and enable/disable NMI sources
Retrieve the SRAM/Flash size through software calls
Disable/enable SRAM banks completely as well as disable retention during sleep
Enable/disable GPIO glitch filters
Change the type of reset that occurs on a WDT violation
21.2
Programming Example
The DriverLib package contains a variety of different code examples that demonstrate the usage
of the SysCtl module. These code examples are accessible under the examples/ folder of the
MSPWare release as well as through TI Resource Explorer if using Code Composer Studio.
These code examples provide a comprehensive list of use cases as well as practical applications
involving each module.
Below is a very brief code example showing how to retrieve the Flash and SRAM sizes using a
software API. This is useful if the programmer is making a program that is meant to be run on
multiple devices in the MSP432 family with different memory footprints.
int main(void)
{
/* Variables we will store the sizes in. Declared volatile so the compiler
* does not optimize out
*/
volatile uint32_t sramSize, flashSize;
/* Halting the Watchdog */
MAP_WDT_A_holdTimer();
sramSize = MAP_SysCtl_getSRAMSize();
flashSize = MAP_SysCtl_getFlashSize();
/* No operation. Set Breakpoint here */
__no_operation();
}
Thu Jan 21 2016 12:34:41 AM
308
System Control Module (SysCtl)
21.3
Definitions
Functions
void SysCtl_disableGlitchFilter (void)
void SysCtl_disableNMISource (uint_fast8_t flags)
void SysCtl_disablePeripheralAtCPUHalt (uint_fast16_t devices)
void SysCtl_disableSRAMBank (uint_fast8_t sramBank)
void SysCtl_disableSRAMBankRetention (uint_fast8_t sramBank)
void SysCtl_enableGlitchFilter (void)
void SysCtl_enableNMISource (uint_fast8_t flags)
void SysCtl_enablePeripheralAtCPUHalt (uint_fast16_t devices)
void SysCtl_enableSRAMBank (uint_fast8_t sramBank)
void SysCtl_enableSRAMBankRetention (uint_fast8_t sramBank)
uint_least32_t SysCtl_getFlashSize (void)
uint_fast8_t SysCtl_getNMISourceStatus (void)
uint_least32_t SysCtl_getSRAMSize (void)
uint_fast16_t SysCtl_getTempCalibrationConstant (uint32_t refVoltage, uint32_t temperature)
void SysCtl_getTLVInfo (uint_fast8_t tag, uint_fast8_t instance, uint_fast8_t ∗length, uint32_t
∗∗data_address)
void SysCtl_rebootDevice (void)
void SysCtl_setWDTPasswordViolationResetType (uint_fast8_t resetType)
void SysCtl_setWDTTimeoutResetType (uint_fast8_t resetType)
21.3.1 Detailed Description
The code for this module is contained in driverlib/sysctl.c, with driverlib/sysctl.h
containing the API declarations for use by applications.
Thu Jan 21 2016 12:34:41 AM
309
System Control Module (SysCtl)
21.3.2 Function Documentation
21.3.2.1 void SysCtl_disableGlitchFilter ( void )
Disables glitch suppression on the reset pin of the device. Refer to the device data sheet for
specific information about glitch suppression
Returns
None.
21.3.2.2 void SysCtl_disableNMISource ( uint_fast8_t flags )
Disables NMIs for the provided modules. When disabled, a NMI flag will not occur when a fault
condition comes from the corresponding modules.
Parameters
flags
The NMI sources to disable Can be a bitwise OR of the following parameters:
SYSCTL_NMIPIN_SRC,
SYSCTL_PCM_SRC,
SYSCTL_PSS_SRC,
SYSCTL_CS_SRC
Referenced by CS_startHFXTWithTimeout(), and CS_startLFXTWithTimeout().
21.3.2.3 void SysCtl_disablePeripheralAtCPUHalt ( uint_fast16_t devices )
Makes it so that the provided peripherals will either halt execution after a CPU HALT. Parameters
in this function can be combined to account for multiple peripherals. By default, all peripherals
keep running after a CPU HALT.
Parameters
devices
The peripherals to disable after a CPU HALT
The devices parameter can be a bitwise OR of the following values: This can be a bitwise OR of
the following values:
SYSCTL_PERIPH_DMA,
SYSCTL_PERIPH_WDT,
SYSCTL_PERIPH_ADC,
SYSCTL_PERIPH_EUSCIB3,
SYSCTL_PERIPH_EUSCIB2,
SYSCTL_PERIPH_EUSCIB1
SYSCTL_PERIPH_EUSCIB0,
SYSCTL_PERIPH_EUSCIA3,
SYSCTL_PERIPH_EUSCIA2
Thu Jan 21 2016 12:34:41 AM
310
System Control Module (SysCtl)
SYSCTL_PERIPH_EUSCIA1,
SYSCTL_PERIPH_EUSCIA0,
SYSCTL_PERIPH_TIMER32_0_MODULE,
SYSCTL_PERIPH_TIMER16_3,
SYSCTL_PERIPH_TIMER16_2,
SYSCTL_PERIPH_TIMER16_1,
SYSCTL_PERIPH_TIMER16_0
Returns
None.
21.3.2.4 void SysCtl_disableSRAMBank ( uint_fast8_t sramBank )
Disables a set of banks in the SRAM. This can be used to optimize power consumption when
every SRAM bank isn’t needed. It is important to note that when a higher bank is disabled, all of
the SRAM banks above that bank are also disabled. For example, if the user disables
SYSCTL_SRAM_BANK5, the banks SYSCTL_SRAM_BANK6 through SYSCTL_SRAM_BANK7
will be disabled.
Parameters
sramBank
The SRAM bank tier to disable. Must be only one of the following values:
SYSCTL_SRAM_BANK1,
SYSCTL_SRAM_BANK2,
SYSCTL_SRAM_BANK3,
SYSCTL_SRAM_BANK4,
SYSCTL_SRAM_BANK5,
SYSCTL_SRAM_BANK6,
SYSCTL_SRAM_BANK7
Note
SYSCTL_SRAM_BANK0 is reserved and always enabled.
Returns
None.
21.3.2.5 void SysCtl_disableSRAMBankRetention ( uint_fast8_t sramBank )
Disables retention of the specified SRAM bank register when the device goes into LPM3 mode.
When the system is placed in LPM3 mode, the SRAM banks specified with this function will not be
placed into retention mode. By default, retention of every SRAM bank except
SYSCTL_SRAM_BANK0 (reserved) is disabled. Retention of individual banks can be set without
the restrictions of the enable/disable SRAM bank functions.
Thu Jan 21 2016 12:34:41 AM
311
System Control Module (SysCtl)
Parameters
sramBank
The SRAM banks to disable retention Can be a bitwise OR of the following values:
SYSCTL_SRAM_BANK1,
SYSCTL_SRAM_BANK2,
SYSCTL_SRAM_BANK3,
SYSCTL_SRAM_BANK4,
SYSCTL_SRAM_BANK5,
SYSCTL_SRAM_BANK6,
SYSCTL_SRAM_BANK7
Note
SYSCTL_SRAM_BANK0 is reserved and retention is always enabled.
Returns
None.
21.3.2.6 void SysCtl_enableGlitchFilter ( void )
Enables glitch suppression on the reset pin of the device. Refer to the device data sheet for
specific information about glitch suppression
Returns
None.
21.3.2.7 void SysCtl_enableNMISource ( uint_fast8_t flags )
Enables NMIs for the provided modules. When enabled, a NMI flag will occur when a fault
condition comes from the corresponding modules.
Parameters
flags
The NMI sources to enable Can be a bitwise OR of the following parameters:
SYSCTL_NMIPIN_SRC,
SYSCTL_PCM_SRC,
SYSCTL_PSS_SRC,
SYSCTL_CS_SRC
Referenced by CS_startHFXTWithTimeout(), and CS_startLFXTWithTimeout().
21.3.2.8 void SysCtl_enablePeripheralAtCPUHalt ( uint_fast16_t devices )
Makes it so that the provided peripherals will either halt execution after a CPU HALT. Parameters
in this function can be combined to account for multiple peripherals. By default, all peripherals
Thu Jan 21 2016 12:34:41 AM
312
System Control Module (SysCtl)
keep running after a CPU HALT.
Thu Jan 21 2016 12:34:41 AM
313
System Control Module (SysCtl)
Parameters
devices
The peripherals to continue running after a CPU HALT This can be a bitwise OR of the
following values:
SYSCTL_PERIPH_DMA,
SYSCTL_PERIPH_WDT,
SYSCTL_PERIPH_ADC,
SYSCTL_PERIPH_EUSCIB3,
SYSCTL_PERIPH_EUSCIB2,
SYSCTL_PERIPH_EUSCIB1
SYSCTL_PERIPH_EUSCIB0,
SYSCTL_PERIPH_EUSCIA3,
SYSCTL_PERIPH_EUSCIA2
SYSCTL_PERIPH_EUSCIA1,
SYSCTL_PERIPH_EUSCIA0,
SYSCTL_PERIPH_TIMER32_0_MODULE,
SYSCTL_PERIPH_TIMER16_3,
SYSCTL_PERIPH_TIMER16_2,
SYSCTL_PERIPH_TIMER16_1,
SYSCTL_PERIPH_TIMER16_0
Returns
None.
21.3.2.9 void SysCtl_enableSRAMBank ( uint_fast8_t sramBank )
Enables a set of banks in the SRAM. This can be used to optimize power consumption when every
SRAM bank isn’t needed. It is important to note that when a higher bank is enabled, all of the
SRAM banks below that bank are also enabled. For example, if the user enables
SYSCTL_SRAM_BANK7, the banks SYSCTL_SRAM_BANK1 through SYSCTL_SRAM_BANK7
will be enabled (SRAM_BANK0 is reserved and always enabled).
Parameters
sramBank
The SRAM bank tier to enable. Must be only one of the following values:
SYSCTL_SRAM_BANK1,
SYSCTL_SRAM_BANK2,
SYSCTL_SRAM_BANK3,
SYSCTL_SRAM_BANK4,
SYSCTL_SRAM_BANK5,
SYSCTL_SRAM_BANK6,
SYSCTL_SRAM_BANK7
Thu Jan 21 2016 12:34:41 AM
314
System Control Module (SysCtl)
Note
SYSCTL_SRAM_BANK0 is reserved and always enabled.
Returns
None.
21.3.2.10 void SysCtl_enableSRAMBankRetention ( uint_fast8_t sramBank )
Enables retention of the specified SRAM bank register when the device goes into LPM3 mode.
When the system is placed in LPM3 mode, the SRAM banks specified with this function will be
placed into retention mode. By default, retention of every SRAM bank except
SYSCTL_SRAM_BANK0 (reserved) is disabled. Retention of individual banks can be set without
the restrictions of the enable/disable functions.
Parameters
sramBank
The SRAM banks to enable retention Can be a bitwise OR of the following values:
SYSCTL_SRAM_BANK1,
SYSCTL_SRAM_BANK2,
SYSCTL_SRAM_BANK3,
SYSCTL_SRAM_BANK4,
SYSCTL_SRAM_BANK5,
SYSCTL_SRAM_BANK6,
SYSCTL_SRAM_BANK7
Note
SYSCTL_SRAM_BANK0 is reserved and retention is always enabled.
Returns
None.
21.3.2.11 uint_least32_t SysCtl_getFlashSize ( void )
Gets the size of the flash.
Returns
The total number of bytes of flash.
Referenced by FlashCtl_getMemoryInfo(), FlashCtl_performMassErase(), and
FlashCtl_verifyMemory().
21.3.2.12 uint_fast8_t SysCtl_getNMISourceStatus ( void )
Returns the current sources of NMIs that are enabled
Thu Jan 21 2016 12:34:41 AM
315
System Control Module (SysCtl)
Returns
Bitwise OR of NMI flags that are enabled
Referenced by CS_startHFXTWithTimeout(), and CS_startLFXTWithTimeout().
21.3.2.13 uint_least32_t SysCtl_getSRAMSize ( void )
Gets the size of the SRAM.
Returns
The total number of bytes of SRAM.
21.3.2.14 uint_fast16_t SysCtl_getTempCalibrationConstant ( uint32_t refVoltage, uint32_t
temperature )
Retrieves the calibration constant of the temperature sensor to be used in temperature calculation.
Parameters
refVoltage
Reference voltage being used.
The refVoltage parameter must be only one of the following values:
SYSCTL_1_2V_REF
SYSCTL_1_45V_REF
SYSCTL_2_5V_REF
Parameters
temperature
is the calibration temperature that the user wants to be returned.
The temperature parameter must be only one of the following values:
SYSCTL_30_DEGREES_C
SYSCTL_85_DEGREES_C
Returns
None.
21.3.2.15 void SysCtl_getTLVInfo ( uint_fast8_t tag, uint_fast8_t instance, uint_fast8_t ∗
length, uint32_t ∗∗ data_address )
The TLV structure uses a tag or base address to identify segments of the table where information
is stored. Some examples of TLV tags are Peripheral Descriptor, Interrupts, Info Block and Die
Record. This function retrieves the value of a tag and the length of the tag.
Thu Jan 21 2016 12:34:41 AM
316
System Control Module (SysCtl)
Parameters
tag
represents the tag for which the information needs to be retrieved. Valid values are:
TLV_TAG_RESERVED1
TLV_TAG_RESERVED2
TLV_TAG_CS
TLV_TAG_FLASHCTL
TLV_TAG_ADC14
TLV_TAG_RESERVED6
TLV_TAG_RESERVED7
TLV_TAG_REF
TLV_TAG_RESERVED9
TLV_TAG_RESERVED10
TLV_TAG_DEVINFO
TLV_TAG_DIEREC
TLV_TAG_RANDNUM
TLV_TAG_RESERVED14
instance
length
data_address
In some cases a specific tag may have more than one instance. For example there may
be multiple instances of timer calibration data present under a single Timer Cal tag. This
variable specifies the instance for which information is to be retrieved (0, 1, etc.). When
only one instance exists; 0 is passed.
Acts as a return through indirect reference. The function retrieves the value of the TLV tag
length. This value is pointed to by ∗length and can be used by the application level once
the function is called. If the specified tag is not found then the pointer is null 0.
acts as a return through indirect reference. Once the function is called data_address
points to the pointer that holds the value retrieved from the specified TLV tag. If the
specified tag is not found then the pointer is null 0.
Returns
None
Referenced by CS_getDCOFrequency(), CS_setDCOFrequency(), FlashCtl_eraseSector(), and
FlashCtl_programMemory().
21.3.2.16 void SysCtl_rebootDevice ( void )
Reboots the device and causes the device to re-initialize itself.
Returns
This function does not return.
21.3.2.17 void SysCtl_setWDTPasswordViolationResetType ( uint_fast8_t resetType )
Sets the type of RESET that happens when a watchdog password violation occurs.
Thu Jan 21 2016 12:34:41 AM
317
System Control Module (SysCtl)
Parameters
resetType
The type of reset to set
The resetType parameter must be only one of the following values:
SYSCTL_HARD_RESET,
SYSCTL_SOFT_RESET
Returns
None.
Referenced by WDT_A_setPasswordViolationReset().
21.3.2.18 void SysCtl_setWDTTimeoutResetType ( uint_fast8_t resetType )
Sets the type of RESET that happens when a watchdog timeout occurs.
Parameters
resetType
The type of reset to set
The resetType parameter must be only one of the following values:
SYSCTL_HARD_RESET,
SYSCTL_SOFT_RESET
Returns
None.
Referenced by WDT_A_setTimeoutReset().
Thu Jan 21 2016 12:34:41 AM
318
System Tick (SysTick)
22
System Tick (SysTick)
Module Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .319
Programming Example . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .319
Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 320
22.1
Module Operation
SysTick is a simple timer that is part of the NVIC controller in the Cortex-M microprocessor. Its
intended purpose is to provide a periodic interrupt for an RTOS, but it can be used for other simple
timing purposes.
The SysTick interrupt handler does not need to clear the SysTick interrupt source as it is cleared
automatically by the NVIC when the SysTick interrupt handler is called.
22.2
Programming Example
The DriverLib package contains a variety of different code examples that demonstrate the usage
of the SysTick module. These code examples are accessible under the examples/ folder of the
MSPWare release as well as through TI Resource Explorer if using Code Composer Studio.
These code examples provide a comprehensive list of use cases as well as practical applications
involving each module.
Below is a very brief code example showing how to configure the SysTick module to interrupt
periodically and blink an LED attached to P1.0.
int main(void)
{
/* Halting the Watchdog */
MAP_WDT_A_holdTimer();
/* Configuring GPIO as an output */
MAP_GPIO_setAsOutputPin(GPIO_PORT_P1,
GPIO_PIN0);
/* Configuring SysTick to trigger at 1500000 (MCLK is 3MHz so this will make
* it toggle every 0.5s) */
MAP_SysTick_enableModule();
MAP_SysTick_setPeriod(1500000);
MAP_Interrupt_enableSleepOnIsrExit();
MAP_SysTick_enableInterrupt();
/* Enabling MASTER interrupts */
MAP_Interrupt_enableMaster();
while (1)
{
MAP_PCM_gotoLPM0();
}
}
void SysTick_Handler(void)
{
MAP_GPIO_toggleOutputOnPin(GPIO_PORT_P1,
}
Thu Jan 21 2016 12:34:41 AM
GPIO_PIN0);
319
System Tick (SysTick)
22.3
Definitions
Functions
void SysTick_disableInterrupt (void)
void SysTick_disableModule (void)
void SysTick_enableInterrupt (void)
void SysTick_enableModule (void)
uint32_t SysTick_getPeriod (void)
uint32_t SysTick_getValue (void)
void SysTick_registerInterrupt (void(∗intHandler)(void))
void SysTick_setPeriod (uint32_t period)
void SysTick_unregisterInterrupt (void)
22.3.1 Detailed Description
The code for this module is contained in driverlib/systick.c, with driverlib/systick.h
containing the API declarations for use by applications.
Thu Jan 21 2016 12:34:41 AM
320
System Tick (SysTick)
22.3.2 Function Documentation
22.3.2.1 void SysTick_disableInterrupt ( void )
Disables the SysTick interrupt.
This function disables the SysTick interrupt, preventing it from being reflected to the processor.
Returns
None.
22.3.2.2 void SysTick_disableModule ( void )
Disables the SysTick counter.
This function stops the SysTick counter. If an interrupt handler has been registered, it is not called
until SysTick is restarted.
Returns
None.
22.3.2.3 void SysTick_enableInterrupt ( void )
Enables the SysTick interrupt.
This function enables the SysTick interrupt, allowing it to be reflected to the processor.
Note
The SysTick interrupt handler is not required to clear the SysTick interrupt source because it
is cleared automatically by the NVIC when the interrupt handler is called.
Returns
None.
22.3.2.4 void SysTick_enableModule ( void )
Enables the SysTick counter.
This function starts the SysTick counter. If an interrupt handler has been registered, it is called
when the SysTick counter rolls over.
Note
Calling this function causes the SysTick counter to (re)commence counting from its current
value. The counter is not automatically reloaded with the period as specified in a previous
call to SysTick_setPeriod(). If an immediate reload is required, the NVIC_ST_CURRENT
register must be written to force the reload. Any write to this register clears the SysTick
counter to 0 and causes a reload with the supplied period on the next clock.
Thu Jan 21 2016 12:34:41 AM
321
System Tick (SysTick)
Returns
None.
22.3.2.5 uint32_t SysTick_getPeriod ( void )
Gets the period of the SysTick counter.
This function returns the rate at which the SysTick counter wraps, which equates to the number of
processor clocks between interrupts.
Returns
Returns the period of the SysTick counter.
22.3.2.6 uint32_t SysTick_getValue ( void )
Gets the current value of the SysTick counter.
This function returns the current value of the SysTick counter, which is a value between the period
- 1 and zero, inclusive.
Returns
Returns the current value of the SysTick counter.
22.3.2.7 void SysTick_registerInterrupt ( void(∗)(void) intHandler )
Registers an interrupt handler for the SysTick interrupt.
Parameters
intHandler
is a pointer to the function to be called when the SysTick interrupt occurs.
This function registers the handler to be called when a SysTick interrupt occurs.
See Also
Interrupt_registerInterrupt() for important information about registering interrupt handlers.
Returns
None.
References Interrupt_registerInterrupt().
22.3.2.8 void SysTick_setPeriod ( uint32_t period )
Sets the period of the SysTick counter.
Thu Jan 21 2016 12:34:41 AM
322
System Tick (SysTick)
Parameters
period
is the number of clock ticks in each period of the SysTick counter and must be between 1
and 16, 777, 216, inclusive.
This function sets the rate at which the SysTick counter wraps, which equates to the number of
processor clocks between interrupts.
Note
Calling this function does not cause the SysTick counter to reload immediately. If an
immediate reload is required, the NVIC_ST_CURRENT register must be written. Any write to
this register clears the SysTick counter to 0 and causes a reload with the period supplied
here on the next clock after SysTick is enabled.
Returns
None.
22.3.2.9 void SysTick_unregisterInterrupt ( void )
Unregisters the interrupt handler for the SysTick interrupt.
This function unregisters the handler to be called when a SysTick interrupt occurs.
See Also
Interrupt_registerInterrupt() for important information about registering interrupt handlers.
Returns
None.
References Interrupt_unregisterInterrupt().
Thu Jan 21 2016 12:34:41 AM
323
32-bit ARM Timer (Timer32)
23
32-bit ARM Timer (Timer32)
Module Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .324
Basic Operation Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 324
Programming Example . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .325
Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 326
23.1
Module Operation
The Timer32 module in MSP432 is a simple 32-bit (or 16-bit depending on configuration) down
counter which was implemented by ARM. While the user’s guide for Timer32 treats the module as
one unified timer, the DriverLib API separates the two timers into two separate modules. To
choose between the module, the user either provides TIMER32_0 or TIMER32_1 to the timer in
order to specify which timer is to be used.
23.2
Basic Operation Modes
Free Run Mode In free run mode, the timer will run from a value of UINT16_MAX or
UINT32_MAX (depending on what resolution is selected).
Periodic Mode In periodic mode, the timer will run to a specified period by the user.
For both periodic and free run modes, the one shot boolean option in the Timer32_startTimer()
function. If specified, when the count reaches zero from the specified period the timer will stop and
not automatically resume with the next iteration of the count.
Thu Jan 21 2016 12:34:41 AM
324
32-bit ARM Timer (Timer32)
23.3
Programming Example
The DriverLib package contains a variety of different code examples that demonstrate the usage
of the Timer32 module. These code examples are accessible under the examples/ folder of the
MSPWare release as well as through TI Resource Explorer if using Code Composer Studio.
These code examples provide a comprehensive list of use cases as well as practical applications
involving each module.
Below is a very brief code example showing how to configure the Timer32 as a simple down
counter with interrupts enabled:
int main(void)
{
volatile uint32_t curValue;
/* Holding the Watchdog */
MAP_WDT_A_holdTimer();
/* Initializing Timer32 in module in 32-bit free-run mode (with max value
* of 0xFFFFFFFF
*/
MAP_Timer32_initModule(TIMER32_BASE, TIMER32_PRESCALER_256, TIMER32_32BIT,
TIMER32_FREE_RUN_MODE);
/* Starting the timer */
MAP_Timer32_startTimer(TIMER32_BASE,
true);
while(1)
{
/* Getting the current value of the Timer32 */
curValue = MAP_Timer32_getValue(TIMER32_BASE);
}
}
Thu Jan 21 2016 12:34:41 AM
325
32-bit ARM Timer (Timer32)
23.4
Definitions
Functions
void Timer32_clearInterruptFlag (uint32_t timer)
void Timer32_disableInterrupt (uint32_t timer)
void Timer32_enableInterrupt (uint32_t timer)
uint32_t Timer32_getInterruptStatus (uint32_t timer)
uint32_t Timer32_getValue (uint32_t timer)
void Timer32_haltTimer (uint32_t timer)
void Timer32_initModule (uint32_t timer, uint32_t preScaler, uint32_t resolution, uint32_t
mode)
void Timer32_registerInterrupt (uint32_t timerInterrupt, void(∗intHandler)(void))
void Timer32_setCount (uint32_t timer, uint32_t count)
void Timer32_setCountInBackground (uint32_t timer, uint32_t count)
void Timer32_startTimer (uint32_t timer, bool oneShot)
void Timer32_unregisterInterrupt (uint32_t timerInterrupt)
23.4.1 Detailed Description
The code for this module is contained in driverlib/timer32.c, with driverlib/timer32.h
containing the API declarations for use by applications.
Thu Jan 21 2016 12:34:41 AM
326
32-bit ARM Timer (Timer32)
23.4.2 Function Documentation
23.4.2.1 void Timer32_clearInterruptFlag ( uint32_t timer )
Clears Timer32 interrupt source.
Parameters
timer
is the instance of the Timer32 module. Valid parameters must be one of the following
values:
TIMER32_0_BASE
TIMER32_1_BASE
The Timer32 interrupt source is cleared, so that it no longer asserts.
Returns
None.
23.4.2.2 void Timer32_disableInterrupt ( uint32_t timer )
Disables a Timer32 interrupt source.
Parameters
timer
is the instance of the Timer32 module. Valid parameters must be one of the following
values:
TIMER32_0_BASE
TIMER32_1_BASE
Disables the indicated Timer32 interrupt source.
Returns
None.
23.4.2.3 void Timer32_enableInterrupt ( uint32_t timer )
Enables a Timer32 interrupt source.
Parameters
timer
is the instance of the Timer32 module. Valid parameters must be one of the following
values:
TIMER32_0_BASE
TIMER32_1_BASE
Enables the indicated Timer32 interrupt source.
Thu Jan 21 2016 12:34:41 AM
327
32-bit ARM Timer (Timer32)
Returns
None.
23.4.2.4 uint32_t Timer32_getInterruptStatus ( uint32_t timer )
Gets the current Timer32 interrupt status.
Parameters
timer
is the instance of the Timer32 module. Valid parameters must be one of the following
values:
TIMER32_0_BASE
TIMER32_1_BASE
This returns the interrupt status for the Timer32 module. A positive value will indicate that an
interrupt is pending while a zero value will indicate that no interrupt is pending.
Returns
The current interrupt status
23.4.2.5 uint32_t Timer32_getValue ( uint32_t timer )
Returns the current value of the timer.
Parameters
timer
is the instance of the Timer32 module. Valid parameters must be one of the following
values:
TIMER32_0_BASE
TIMER32_1_BASE
Returns
The current count of the timer.
23.4.2.6 void Timer32_haltTimer ( uint32_t timer )
Halts the timer. Current count and setting values are preserved.
Parameters
timer
is the instance of the Timer32 module. Valid parameters must be one of the following
values:
TIMER32_0_BASE
TIMER32_1_BASE
Thu Jan 21 2016 12:34:41 AM
328
32-bit ARM Timer (Timer32)
Returns
None
23.4.2.7 void Timer32_initModule ( uint32_t timer, uint32_t preScaler, uint32_t resolution,
uint32_t mode )
Initializes the Timer32 module
Parameters
timer
is the instance of the Timer32 module. Valid parameters must be one of the following
values:
TIMER32_0_BASE
TIMER32_1_BASE
preScaler
is the prescaler (or divider) to apply to the clock source given to the Timer32 module. Valid
values are
TIMER32_PRESCALER_1 [DEFAULT]
TIMER32_PRESCALER_16
TIMER32_PRESCALER_256
resolution
is the bit resolution of the Timer32 module. Valid values are
TIMER32_16BIT [DEFAULT]
TIMER32_32BIT
mode
selects between free run and periodic mode. In free run mode, the value of the timer
is reset to UINT16_MAX (for 16-bit mode) or UINT32_MAX (for 16-bit mode) when
the timer reaches zero. In periodic mode, the timer is reset to the value set by the
Timer32_setCount function. Valid values are
TIMER32_FREE_RUN_MODE [DEFAULT]
TIMER32_PERIODIC_MODE
Thu Jan 21 2016 12:34:41 AM
329
32-bit ARM Timer (Timer32)
Returns
None.
23.4.2.8 void Timer32_registerInterrupt ( uint32_t timerInterrupt, void(∗)(void) intHandler )
Registers an interrupt handler for Timer32 interrupts.
Parameters
timerInterrupt
is the specific interrupt to register. For the Timer32 module, there are a total of three different interrupts: one interrupt for each two Timer32 modules, and a "combined" interrupt
which is a logical OR of each individual Timer32 interrupt.
TIMER32_0_INTERRUPT
TIMER32_1_INTERRUPT
TIMER32_COMBINED_INTERRUPT
intHandler
is a pointer to the function to be called when the Timer32 interrupt occurs.
This function registers the handler to be called when an Timer32 interrupt occurs. This function
enables the global interrupt in the interrupt controller; specific Timer32 interrupts must be enabled
via Timer32_enableInterrupt(). It is the interrupt handler’s responsibility to clear the interrupt
source via Timer32_clearInterruptFlag().
Returns
None.
References Interrupt_enableInterrupt(), and Interrupt_registerInterrupt().
23.4.2.9 void Timer32_setCount ( uint32_t timer, uint32_t count )
Sets the count of the timer and resets the current value to the value passed. This value is set on
the next rising edge of the clock provided to the timer module
Parameters
timer
is the instance of the Timer32 module. Valid parameters must be one of the following
values:
TIMER32_0_BASE
TIMER32_1_BASE
count
Value of the timer to set. Note that if the timer is in 16-bit mode and a value is passed in
that exceeds UINT16_MAX, the value will be truncated to UINT16_MAX.
Also note that if the timer is operating in periodic mode, the value passed into this function will
represent the new period of the timer (the value which is reloaded into the timer each time it
reaches a zero value).
Returns
None
Thu Jan 21 2016 12:34:41 AM
330
32-bit ARM Timer (Timer32)
23.4.2.10 void Timer32_setCountInBackground ( uint32_t timer, uint32_t count )
Sets the count of the timer without resetting the current value. When the current value of the timer
reaches zero, the value passed into this function will be set as the new count value.
Thu Jan 21 2016 12:34:41 AM
331
32-bit ARM Timer (Timer32)
Parameters
timer
is the instance of the Timer32 module. Valid parameters must be one of the following
values:
TIMER32_0_BASE
TIMER32_1_BASE
count
Value of the timer to set in the background. Note that if the timer is in 16-bit mode
and a value is passed in that exceeds UINT16_MAX, the value will be truncated to
UINT16_MAX.
Also note that if the timer is operating in periodic mode, the value passed into this function will
represent the new period of the timer (the value which is reloaded into the timer each time it
reaches a zero value).
Returns
None
23.4.2.11 void Timer32_startTimer ( uint32_t timer, bool oneShot )
Starts the timer. The Timer32_initModule function should be called (in conjunction with
Timer32_setCount if periodic mode is desired) prior to
Parameters
timer
is the instance of the Timer32 module. Valid parameters must be one of the following
values:
TIMER32_0_BASE
TIMER32_1_BASE
oneShot
sets whether the Timer32 module operates in one shot or continuous mode. In one shot
mode, the timer will halt when a zero is reached and stay halted until either:
The user calls the Timer32PeriodSet function
The Timer32_initModule is called to reinitialize the timer with one-shot mode disabled.
A true value will cause the timer to operate in one shot mode while a false value will cause the
timer to operate in continuous mode
Returns
None
23.4.2.12 void Timer32_unregisterInterrupt ( uint32_t timerInterrupt )
Unregisters the interrupt handler for the Timer32 interrupt.
Thu Jan 21 2016 12:34:41 AM
332
32-bit ARM Timer (Timer32)
Parameters
timerInterrupt
is the specific interrupt to register. For the Timer32 module, there are a total of three different interrupts: one interrupt for each two Timer32 modules, and a "combined" interrupt
which is a logical OR of each individual Timer32 interrupt.
TIMER32_0_INTERRUPT
TIMER32_1_INTERRUPT
TIMER32_COMBINED_INTERRUPT
This function unregisters the handler to be called when a Timer32 interrupt occurs. This function
also masks off the interrupt in the interrupt controller so that the interrupt handler no longer is
called.
See Also
Interrupt_registerInterrupt() for important information about registering interrupt handlers.
Returns
None.
References Interrupt_disableInterrupt(), and Interrupt_unregisterInterrupt().
Thu Jan 21 2016 12:34:41 AM
333
16-Bit Timer with Precision PWM (Timer_A)
24
16-Bit Timer with Precision PWM (Timer_A)
Module Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .334
Basic Operation Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 334
Programming Example . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .335
Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 336
24.1
Module Operation
TimerA is a 16-bit timer/counter with multiple capture/compare registers. TimerA can support
multiple capture/compares, PWM outputs, and interval timing. TimerA also has extensive interrupt
capabilities. Interrupts may be generated from the counter on overflow conditions and from each
of the capture/compare registers.
This peripheral API handles Timer A hardware peripheral.
TimerA features include:
Asynchronous 16-bit timer/counter with four operating modes
Selectable and configurable clock source
Up to seven configurable capture/compare registers
Configurable outputs with pulse width modulation (PWM) capability
Asynchronous input and output latching
Interrupt vector register for fast decoding of all Timer interrupts
24.2
Basic Operation Modes
TimerA can operate in 3 modes:
Continuous Mode
Up Mode
Down Mode
TimerA Interrupts may be generated on counter overflow conditions and during capture compare
events.
The TimerA may also be used to generate PWM outputs. PWM outputs can be generated by
initializing the compare mode with TimerA_initCompare() and the necessary parameters. The
PWM may be customized by selecting a desired timer mode (continuous/up/upDown), duty cycle,
output mode, timer period etc. The library also provides a simpler way to generate PWM using
TimerA_generatePWM() API. However the level of customization and the kinds of PWM generated
are limited in this API. Depending on how complex the PWM is and what level of customization is
required, the user can use TimerA_generatePWM() or a combination of TimerA_initCompare and
timer start APIs.
The TimerA API provides a set of functions for dealing with the TimerA module. Functions are
provided to configure and control the timer, along with functions to modify timer/counter values,
and to manage interrupt handling for the timer.
Thu Jan 21 2016 12:34:41 AM
334
16-Bit Timer with Precision PWM (Timer_A)
Control is also provided over interrupt sources and events. Interrupts can be generated to indicate
that an event has been captured.
24.3
Programming Example
The DriverLib package contains a variety of different code examples that demonstrate the usage
of the TimerA module. These code examples are accessible under the examples/ folder of the
MSPWare release as well as through TI Resource Explorer if using Code Composer Studio.
These code examples provide a comprehensive list of use cases as well as practical applications
involving each module.
Below is a very brief code example showing how to generate a PWM signal using the TimerA
DriverLib module.
Below is the configuration parameter for the TimerA PWM config API:
/* Timer_A PWM Configuration Parameter */
Timer_A_PWMConfig pwmConfig =
{
TIMER_A_CLOCKSOURCE_SMCLK,
TIMER_A_CLOCKSOURCE_DIVIDER_1,
32000,
TIMER_A_CAPTURECOMPARE_REGISTER_1,
TIMER_A_OUTPUTMODE_RESET_SET,
3200
};
The next snippet of code is used to actually configure the PWM signal:
/* Setting MCLK to REFO at 128Khz for LF mode
* Setting SMCLK to 64Khz */
MAP_CS_setReferenceOscillatorFrequency(CS_REFO_128KHZ);
MAP_CS_initClockSignal(CS_MCLK, CS_REFOCLK_SELECT, CS_CLOCK_DIVIDER_1);
MAP_CS_initClockSignal(CS_SMCLK, CS_REFOCLK_SELECT, CS_CLOCK_DIVIDER_2);
MAP_PCM_setPowerState(PCM_AM_LF_VCORE0);
/* Configuring GPIO2.4 as peripheral output for PWM and P6.7 for button
* interrupt */
MAP_GPIO_setAsPeripheralModuleFunctionOutputPin(GPIO_PORT_P2, GPIO_PIN4,
GPIO_PRIMARY_MODULE_FUNCTION);
MAP_GPIO_setAsInputPinWithPullUpResistor(GPIO_PORT_P1, GPIO_PIN1);
MAP_GPIO_clearInterruptFlag(GPIO_PORT_P1, GPIO_PIN1);
MAP_GPIO_enableInterrupt(GPIO_PORT_P1, GPIO_PIN1);
/* Configuring Timer_A to have a period of approximately 500ms and
* an initial duty cycle of 10% of that (3200 ticks) */
MAP_Timer_A_generatePWM(TIMER_A0_BASE, &pwmConfig);
Thu Jan 21 2016 12:34:41 AM
335
16-Bit Timer with Precision PWM (Timer_A)
24.4
Definitions
Data Structures
struct _Timer_A_CaptureModeConfig
struct _Timer_A_CompareModeConfig
struct _Timer_A_ContinuousModeConfig
struct _Timer_A_PWMConfig
struct _Timer_A_UpDownModeConfig
struct _Timer_A_UpModeConfig
Functions
void Timer_A_clearCaptureCompareInterrupt (uint32_t timer, uint_fast16_t
captureCompareRegister)
void Timer_A_clearInterruptFlag (uint32_t timer)
void Timer_A_clearTimer (uint32_t timer)
void Timer_A_configureContinuousMode (uint32_t timer, const
Timer_A_ContinuousModeConfig ∗config)
void Timer_A_configureUpDownMode (uint32_t timer, const Timer_A_UpDownModeConfig
∗config)
void Timer_A_configureUpMode (uint32_t timer, const Timer_A_UpModeConfig ∗config)
void Timer_A_disableCaptureCompareInterrupt (uint32_t timer, uint_fast16_t
captureCompareRegister)
void Timer_A_disableInterrupt (uint32_t timer)
void Timer_A_enableCaptureCompareInterrupt (uint32_t timer, uint_fast16_t
captureCompareRegister)
void Timer_A_enableInterrupt (uint32_t timer)
void Timer_A_generatePWM (uint32_t timer, const Timer_A_PWMConfig ∗config)
uint_fast16_t Timer_A_getCaptureCompareCount (uint32_t timer, uint_fast16_t
captureCompareRegister)
uint32_t Timer_A_getCaptureCompareEnabledInterruptStatus (uint32_t timer, uint_fast16_t
captureCompareRegister)
uint32_t Timer_A_getCaptureCompareInterruptStatus (uint32_t timer, uint_fast16_t
captureCompareRegister, uint_fast16_t mask)
uint16_t Timer_A_getCounterValue (uint32_t timer)
uint32_t Timer_A_getEnabledInterruptStatus (uint32_t timer)
uint32_t Timer_A_getInterruptStatus (uint32_t timer)
uint_fast8_t Timer_A_getOutputForOutputModeOutBitValue (uint32_t timer, uint_fast16_t
captureCompareRegister)
uint_fast8_t Timer_A_getSynchronizedCaptureCompareInput (uint32_t timer, uint_fast16_t
captureCompareRegister, uint_fast16_t synchronizedSetting)
void Timer_A_initCapture (uint32_t timer, const Timer_A_CaptureModeConfig ∗config)
void Timer_A_initCompare (uint32_t timer, const Timer_A_CompareModeConfig ∗config)
void Timer_A_registerInterrupt (uint32_t timer, uint_fast8_t interruptSelect,
void(∗intHandler)(void))
void Timer_A_setCompareValue (uint32_t timer, uint_fast16_t compareRegister,
uint_fast16_t compareValue)
void Timer_A_setOutputForOutputModeOutBitValue (uint32_t timer, uint_fast16_t
captureCompareRegister, uint_fast8_t outputModeOutBitValue)
void Timer_A_startCounter (uint32_t timer, uint_fast16_t timerMode)
void Timer_A_stopTimer (uint32_t timer)
void Timer_A_unregisterInterrupt (uint32_t timer, uint_fast8_t interruptSelect)
Thu Jan 21 2016 12:34:41 AM
336
16-Bit Timer with Precision PWM (Timer_A)
24.4.1 Detailed Description
The code for this module is contained in driverlib/timer_a.c, with driverlib/timer_a.h
containing the API declarations for use by applications.
Thu Jan 21 2016 12:34:41 AM
337
16-Bit Timer with Precision PWM (Timer_A)
24.4.2 Function Documentation
24.4.2.1 void Timer_A_clearCaptureCompareInterrupt ( uint32_t timer, uint_fast16_t
captureCompareRegister )
Clears the capture-compare interrupt flag
Parameters
timer
is the instance of the Timer_A module. Valid parameters vary from part to part, but can
include:
TIMER_A0_BASE
TIMER_A1_BASE
TIMER_A2_BASE
TIMER_A3_BASE
captureCompareRegister
selects the Capture-compare register being used. Valid values are
TIMER_A_CAPTURECOMPARE_REGISTER_0
TIMER_A_CAPTURECOMPARE_REGISTER_1
TIMER_A_CAPTURECOMPARE_REGISTER_2
TIMER_A_CAPTURECOMPARE_REGISTER_3
TIMER_A_CAPTURECOMPARE_REGISTER_4
TIMER_A_CAPTURECOMPARE_REGISTER_5
TIMER_A_CAPTURECOMPARE_REGISTER_6
Refer to the datasheet to ensure the device has the capture compare register being
used
Returns
None
24.4.2.2 void Timer_A_clearInterruptFlag ( uint32_t timer )
Clears the Timer TAIFG interrupt flag
Parameters
timer
is the instance of the Timer_A module. Valid parameters vary from part to part, but can
include:
TIMER_A0_BASE
TIMER_A1_BASE
TIMER_A2_BASE
TIMER_A3_BASE
Thu Jan 21 2016 12:34:41 AM
338
16-Bit Timer with Precision PWM (Timer_A)
Returns
None
24.4.2.3 void Timer_A_clearTimer ( uint32_t timer )
Reset/Clear the timer clock divider, count direction, count
Parameters
timer
is the instance of the Timer_A module. Valid parameters vary from part to part, but can
include:
TIMER_A0_BASE
TIMER_A1_BASE
TIMER_A2_BASE
TIMER_A3_BASE
Returns
None
24.4.2.4 void Timer_A_configureContinuousMode ( uint32_t timer, const
Timer_A_ContinuousModeConfig ∗ config )
Configures Timer_A in continuous mode.
Parameters
timer
is the instance of the Timer_A module. Valid parameters vary from part to part, but can
include:
TIMER_A0_BASE
TIMER_A1_BASE
TIMER_A2_BASE
TIMER_A3_BASE
config
Configuration structure for Timer_A continuous mode
Configuration options for Timer_A_ContinuousModeConfig structure.
Thu Jan 21 2016 12:34:41 AM
339
16-Bit Timer with Precision PWM (Timer_A)
Parameters
clockSource
selects Clock source. Valid values are
TIMER_A_CLOCKSOURCE_EXTERNAL_TXCLK [Default value]
TIMER_A_CLOCKSOURCE_ACLK
TIMER_A_CLOCKSOURCE_SMCLK
TIMER_A_CLOCKSOURCE_INVERTED_EXTERNAL_TXCLK
timerInterruptEnable_TAIE
is the divider for Clock source. Valid values are:
TIMER_A_CLOCKSOURCE_DIVIDER_1 [Default value]
TIMER_A_CLOCKSOURCE_DIVIDER_2
TIMER_A_CLOCKSOURCE_DIVIDER_4
TIMER_A_CLOCKSOURCE_DIVIDER_8
TIMER_A_CLOCKSOURCE_DIVIDER_3
TIMER_A_CLOCKSOURCE_DIVIDER_5
TIMER_A_CLOCKSOURCE_DIVIDER_6
TIMER_A_CLOCKSOURCE_DIVIDER_7
TIMER_A_CLOCKSOURCE_DIVIDER_10
TIMER_A_CLOCKSOURCE_DIVIDER_12
TIMER_A_CLOCKSOURCE_DIVIDER_14
TIMER_A_CLOCKSOURCE_DIVIDER_16
TIMER_A_CLOCKSOURCE_DIVIDER_20
TIMER_A_CLOCKSOURCE_DIVIDER_24
TIMER_A_CLOCKSOURCE_DIVIDER_28
TIMER_A_CLOCKSOURCE_DIVIDER_32
TIMER_A_CLOCKSOURCE_DIVIDER_40
TIMER_A_CLOCKSOURCE_DIVIDER_48
TIMER_A_CLOCKSOURCE_DIVIDER_56
TIMER_A_CLOCKSOURCE_DIVIDER_64
Thu Jan 21 2016 12:34:41 AM
340
16-Bit Timer with Precision PWM (Timer_A)
timerInterruptEnable_TAIE
is to enable or disable Timer_A interrupt. Valid values are
timerClear
decides if Timer_A clock divider, count direction, count need to be reset. Valid values are
TIMER_A_TAIE_INTERRUPT_ENABLE
TIMER_A_TAIE_INTERRUPT_DISABLE [Default value]
TIMER_A_DO_CLEAR
TIMER_A_SKIP_CLEAR [Default value]
Note
This API does not start the timer. Timer needs to be started when required using the
Timer_A_startCounter API.
Returns
None
24.4.2.5 void Timer_A_configureUpDownMode ( uint32_t timer, const
Timer_A_UpDownModeConfig ∗ config )
Configures Timer_A in up down mode.
Parameters
timer
is the instance of the Timer_A module. Valid parameters vary from part to part, but can
include:
TIMER_A0_BASE
TIMER_A1_BASE
TIMER_A2_BASE
TIMER_A3_BASE
config
Configuration structure for Timer_A UpDown mode
Configuration options for Timer_A_UpDownModeConfig structure.
Parameters
clockSource
selects Clock source. Valid values are
TIMER_A_CLOCKSOURCE_EXTERNAL_TXCLK [Default value]
TIMER_A_CLOCKSOURCE_ACLK
TIMER_A_CLOCKSOURCE_SMCLK
TIMER_A_CLOCKSOURCE_INVERTED_EXTERNAL_TXCLK
Thu Jan 21 2016 12:34:41 AM
341
16-Bit Timer with Precision PWM (Timer_A)
clockSourceDivider
is the divider for Clock source. Valid values are:
TIMER_A_CLOCKSOURCE_DIVIDER_1 [Default value]
TIMER_A_CLOCKSOURCE_DIVIDER_2
TIMER_A_CLOCKSOURCE_DIVIDER_4
TIMER_A_CLOCKSOURCE_DIVIDER_8
TIMER_A_CLOCKSOURCE_DIVIDER_3
TIMER_A_CLOCKSOURCE_DIVIDER_5
TIMER_A_CLOCKSOURCE_DIVIDER_6
TIMER_A_CLOCKSOURCE_DIVIDER_7
TIMER_A_CLOCKSOURCE_DIVIDER_10
TIMER_A_CLOCKSOURCE_DIVIDER_12
TIMER_A_CLOCKSOURCE_DIVIDER_14
TIMER_A_CLOCKSOURCE_DIVIDER_16
TIMER_A_CLOCKSOURCE_DIVIDER_20
TIMER_A_CLOCKSOURCE_DIVIDER_24
TIMER_A_CLOCKSOURCE_DIVIDER_28
TIMER_A_CLOCKSOURCE_DIVIDER_32
TIMER_A_CLOCKSOURCE_DIVIDER_40
TIMER_A_CLOCKSOURCE_DIVIDER_48
TIMER_A_CLOCKSOURCE_DIVIDER_56
TIMER_A_CLOCKSOURCE_DIVIDER_64
Thu Jan 21 2016 12:34:41 AM
342
16-Bit Timer with Precision PWM (Timer_A)
timerPeriod
timerInterruptEnable_TAIE
is the specified Timer_A period
is to enable or disable Timer_A interrupt. Valid values are
TIMER_A_TAIE_INTERRUPT_ENABLE
TIMER_A_TAIE_INTERRUPT_DISABLE [Default value]
captureCom- is to enable or disable Timer_A CCR0 captureComapre interrupt. Valid values are
pareInterruptEnTIMER_A_CCIE_CCR0_INTERRUPT_ENABLE and
able_CCR0_CCIE
TIMER_A_CCIE_CCR0_INTERRUPT_DISABLE [Default value]
timerClear
decides if Timer_A clock divider, count direction, count need to be reset. Valid values are
TIMER_A_DO_CLEAR
TIMER_A_SKIP_CLEAR [Default value]
This API does not start the timer. Timer needs to be started when required using the
Timer_A_startCounter API.
Returns
None
24.4.2.6 void Timer_A_configureUpMode ( uint32_t timer, const
Timer_A_UpModeConfig ∗ config )
Configures Timer_A in up mode.
Parameters
timer
is the instance of the Timer_A module. Valid parameters vary from part to part, but can
include:
TIMER_A0_BASE
TIMER_A1_BASE
TIMER_A2_BASE
TIMER_A3_BASE
config
Configuration structure for Timer_A Up mode
Configuration options for Timer_A_UpModeConfig structure.
Thu Jan 21 2016 12:34:41 AM
343
16-Bit Timer with Precision PWM (Timer_A)
Parameters
clockSource
selects Clock source. Valid values are
TIMER_A_CLOCKSOURCE_EXTERNAL_TXCLK [Default value]
TIMER_A_CLOCKSOURCE_ACLK
TIMER_A_CLOCKSOURCE_SMCLK
TIMER_A_CLOCKSOURCE_INVERTED_EXTERNAL_TXCLK
clockSourceDivider
is the divider for Clock source. Valid values are:
TIMER_A_CLOCKSOURCE_DIVIDER_1 [Default value]
TIMER_A_CLOCKSOURCE_DIVIDER_2
TIMER_A_CLOCKSOURCE_DIVIDER_4
TIMER_A_CLOCKSOURCE_DIVIDER_8
TIMER_A_CLOCKSOURCE_DIVIDER_3
TIMER_A_CLOCKSOURCE_DIVIDER_5
TIMER_A_CLOCKSOURCE_DIVIDER_6
TIMER_A_CLOCKSOURCE_DIVIDER_7
TIMER_A_CLOCKSOURCE_DIVIDER_10
TIMER_A_CLOCKSOURCE_DIVIDER_12
TIMER_A_CLOCKSOURCE_DIVIDER_14
TIMER_A_CLOCKSOURCE_DIVIDER_16
TIMER_A_CLOCKSOURCE_DIVIDER_20
TIMER_A_CLOCKSOURCE_DIVIDER_24
TIMER_A_CLOCKSOURCE_DIVIDER_28
TIMER_A_CLOCKSOURCE_DIVIDER_32
TIMER_A_CLOCKSOURCE_DIVIDER_40
TIMER_A_CLOCKSOURCE_DIVIDER_48
TIMER_A_CLOCKSOURCE_DIVIDER_56
TIMER_A_CLOCKSOURCE_DIVIDER_64
Thu Jan 21 2016 12:34:41 AM
344
16-Bit Timer with Precision PWM (Timer_A)
timerPeriod
timerInterruptEnable_TAIE
is the specified Timer_A period. This is the value that gets written into the CCR0. Limited
to 16 bits[uint16_t]
is to enable or disable Timer_A interrupt. Valid values are:
TIMER_A_TAIE_INTERRUPT_ENABLE and
TIMER_A_TAIE_INTERRUPT_DISABLE [Default value]
captureCom- is to enable or disable Timer_A CCR0 captureComapre interrupt. Valid values are
pareInterruptEnTIMER_A_CCIE_CCR0_INTERRUPT_ENABLE and
able_CCR0_CCIE
TIMER_A_CCIE_CCR0_INTERRUPT_DISABLE [Default value]
timerClear
decides if Timer_A clock divider, count direction, count need to be reset. Valid values are
TIMER_A_DO_CLEAR
TIMER_A_SKIP_CLEAR [Default value]
Note
This API does not start the timer. Timer needs to be started when required using the
Timer_A_startCounter API.
Returns
None
24.4.2.7 void Timer_A_disableCaptureCompareInterrupt ( uint32_t timer, uint_fast16_t
captureCompareRegister )
Disable capture compare interrupt
Parameters
timer
is the instance of the Timer_A module. Valid parameters vary from part to part, but can
include:
TIMER_A0_BASE
TIMER_A1_BASE
TIMER_A2_BASE
TIMER_A3_BASE
Thu Jan 21 2016 12:34:41 AM
345
16-Bit Timer with Precision PWM (Timer_A)
captureCompareRegister
is the selected capture compare register
Returns
None
24.4.2.8 void Timer_A_disableInterrupt ( uint32_t timer )
Disable timer interrupt
Parameters
timer
is the instance of the Timer_A module. Valid parameters vary from part to part, but can
include:
TIMER_A0_BASE
TIMER_A1_BASE
TIMER_A2_BASE
TIMER_A3_BASE
Returns
None
24.4.2.9 void Timer_A_enableCaptureCompareInterrupt ( uint32_t timer, uint_fast16_t
captureCompareRegister )
Enable capture compare interrupt
Parameters
timer
is the instance of the Timer_A module. Valid parameters vary from part to part, but can
include:
TIMER_A0_BASE
TIMER_A1_BASE
TIMER_A2_BASE
TIMER_A3_BASE
Thu Jan 21 2016 12:34:41 AM
346
16-Bit Timer with Precision PWM (Timer_A)
captureCompareRegister
is the selected capture compare register
Returns
None
24.4.2.10 void Timer_A_enableInterrupt ( uint32_t timer )
Enable timer interrupt
Parameters
timer
is the instance of the Timer_A module. Valid parameters vary from part to part, but can
include:
TIMER_A0_BASE
TIMER_A1_BASE
TIMER_A2_BASE
TIMER_A3_BASE
Returns
None
24.4.2.11 void Timer_A_generatePWM ( uint32_t timer, const Timer_A_PWMConfig ∗
config )
Generate a PWM with timer running in up mode
Parameters
timer
is the instance of the Timer_A module. Valid parameters vary from part to part, but can
include:
TIMER_A0_BASE
TIMER_A1_BASE
TIMER_A2_BASE
TIMER_A3_BASE
Thu Jan 21 2016 12:34:41 AM
347
16-Bit Timer with Precision PWM (Timer_A)
config
Configuration structure for Timer_A PWM mode
Configuration options for Timer_A_PWMConfig structure.
Parameters
clockSource
selects Clock source. Valid values are
TIMER_A_CLOCKSOURCE_EXTERNAL_TXCLK
TIMER_A_CLOCKSOURCE_ACLK
TIMER_A_CLOCKSOURCE_SMCLK
TIMER_A_CLOCKSOURCE_INVERTED_EXTERNAL_TXCLK
clockSourceDivider
is the divider for Clock source. Valid values are
TIMER_A_CLOCKSOURCE_DIVIDER_1
TIMER_A_CLOCKSOURCE_DIVIDER_2
TIMER_A_CLOCKSOURCE_DIVIDER_4
TIMER_A_CLOCKSOURCE_DIVIDER_8
TIMER_A_CLOCKSOURCE_DIVIDER_3
TIMER_A_CLOCKSOURCE_DIVIDER_5
TIMER_A_CLOCKSOURCE_DIVIDER_6
TIMER_A_CLOCKSOURCE_DIVIDER_7
TIMER_A_CLOCKSOURCE_DIVIDER_10
TIMER_A_CLOCKSOURCE_DIVIDER_12
TIMER_A_CLOCKSOURCE_DIVIDER_14
TIMER_A_CLOCKSOURCE_DIVIDER_16
TIMER_A_CLOCKSOURCE_DIVIDER_20
TIMER_A_CLOCKSOURCE_DIVIDER_24
TIMER_A_CLOCKSOURCE_DIVIDER_28
TIMER_A_CLOCKSOURCE_DIVIDER_32
TIMER_A_CLOCKSOURCE_DIVIDER_40
TIMER_A_CLOCKSOURCE_DIVIDER_48
TIMER_A_CLOCKSOURCE_DIVIDER_56
TIMER_A_CLOCKSOURCE_DIVIDER_64
Thu Jan 21 2016 12:34:41 AM
348
16-Bit Timer with Precision PWM (Timer_A)
timerPeriod
compareRegister
selects the desired timer period
selects the compare register being used. Valid values are
TIMER_A_CAPTURECOMPARE_REGISTER_0
TIMER_A_CAPTURECOMPARE_REGISTER_1
TIMER_A_CAPTURECOMPARE_REGISTER_2
TIMER_A_CAPTURECOMPARE_REGISTER_3
TIMER_A_CAPTURECOMPARE_REGISTER_4
TIMER_A_CAPTURECOMPARE_REGISTER_5
TIMER_A_CAPTURECOMPARE_REGISTER_6
Refer to datasheet to ensure the device has the capture compare register being used
compareOutputMode
specifies the ouput mode. Valid values are:
TIMER_A_OUTPUTMODE_OUTBITVALUE,
TIMER_A_OUTPUTMODE_SET,
TIMER_A_OUTPUTMODE_TOGGLE_RESET,
TIMER_A_OUTPUTMODE_SET_RESET
TIMER_A_OUTPUTMODE_TOGGLE,
TIMER_A_OUTPUTMODE_RESET,
TIMER_A_OUTPUTMODE_TOGGLE_SET,
TIMER_A_OUTPUTMODE_RESET_SET
dutyCycle
specifies the dutycycle for the generated waveform
Returns
None
24.4.2.12 uint_fast16_t Timer_A_getCaptureCompareCount ( uint32_t timer, uint_fast16_t
captureCompareRegister )
Get current capture compare count
Parameters
timer
is the instance of the Timer_A module. Valid parameters vary from part to part, but can
include:
TIMER_A0_BASE
TIMER_A1_BASE
TIMER_A2_BASE
TIMER_A3_BASE
Thu Jan 21 2016 12:34:41 AM
349
16-Bit Timer with Precision PWM (Timer_A)
captureCompareRegister
selects the Capture register being used. Valid values are
TIMER_A_CAPTURECOMPARE_REGISTER_0
TIMER_A_CAPTURECOMPARE_REGISTER_1
TIMER_A_CAPTURECOMPARE_REGISTER_2
TIMER_A_CAPTURECOMPARE_REGISTER_3
TIMER_A_CAPTURECOMPARE_REGISTER_4
TIMER_A_CAPTURECOMPARE_REGISTER_5
TIMER_A_CAPTURECOMPARE_REGISTER_6
Refer to datasheet to ensure the device has the capture compare register being used
Returns
current count as uint16_t
24.4.2.13 uint32_t Timer_A_getCaptureCompareEnabledInterruptStatus ( uint32_t timer,
uint_fast16_t captureCompareRegister )
Return capture compare interrupt status masked with the enabled interrupts. This function is
useful to call in ISRs to get a list of pending interrupts that are actually enabled and could have
caused the ISR.
Parameters
timer
is the instance of the Timer_A module. Valid parameters vary from part to part, but can
include:
TIMER_A0_BASE
TIMER_A1_BASE
TIMER_A2_BASE
TIMER_A3_BASE
captureCompareRegister
is the selected capture compare register
Returns
uint32_t. The mask of the set flags. Valid values is an OR of
TIMER_A_CAPTURE_OVERFLOW,
TIMER_A_CAPTURECOMPARE_INTERRUPT_FLAG
References Timer_A_getCaptureCompareInterruptStatus().
24.4.2.14 uint32_t Timer_A_getCaptureCompareInterruptStatus ( uint32_t timer,
uint_fast16_t captureCompareRegister, uint_fast16_t mask )
Return capture compare interrupt status
Thu Jan 21 2016 12:34:41 AM
350
16-Bit Timer with Precision PWM (Timer_A)
Parameters
timer
is the instance of the Timer_A module. Valid parameters vary from part to part, but can
include:
TIMER_A0_BASE
TIMER_A1_BASE
TIMER_A2_BASE
TIMER_A3_BASE
captureCompareRegister
mask
is the selected capture compare register
is the mask for the interrupt status Mask value is the logical OR of any of the following:
TIMER_A_CAPTURE_OVERFLOW
TIMER_A_CAPTURECOMPARE_INTERRUPT_FLAG
Returns
uint32_t. The mask of the set flags. Valid values is an OR of
TIMER_A_CAPTURE_OVERFLOW,
TIMER_A_CAPTURECOMPARE_INTERRUPT_FLAG
Referenced by Timer_A_getCaptureCompareEnabledInterruptStatus().
24.4.2.15 uint16_t Timer_A_getCounterValue ( uint32_t timer )
Returns the current value of the specified timer. Note that according to the Timer A user guide,
reading the value of the counter is unreliable if the system clock is asynchronous from the timer
clock. The API addresses this concern by reading the timer count register twice and then
determining the integrity of the value. If the two values are within 10 timer counts of each other,
the value is deemed safe and returned. If not, the process is repeated until a reliable timer value is
determined.
Parameters
timer
is the instance of the Timer_A module. Valid parameters vary from part to part, but can
include:
TIMER_A0_BASE
TIMER_A1_BASE
TIMER_A2_BASE
TIMER_A3_BASE
Thu Jan 21 2016 12:34:41 AM
351
16-Bit Timer with Precision PWM (Timer_A)
Returns
The value of the specified timer
24.4.2.16 uint32_t Timer_A_getEnabledInterruptStatus ( uint32_t timer )
Get timer interrupt status masked with the enabled interrupts. This function is useful to call in ISRs
to get a list of pending interrupts that are actually enabled and could have caused the ISR.
Thu Jan 21 2016 12:34:41 AM
352
16-Bit Timer with Precision PWM (Timer_A)
Parameters
timer
is the instance of the Timer_A module. Valid parameters vary from part to part, but can
include:
TIMER_A0_BASE
TIMER_A1_BASE
TIMER_A2_BASE
TIMER_A3_BASE
Returns
uint32_t. Return interrupt status. Valid values are
TIMER_A_INTERRUPT_PENDING
TIMER_A_INTERRUPT_NOT_PENDING
References Timer_A_getInterruptStatus().
24.4.2.17 uint32_t Timer_A_getInterruptStatus ( uint32_t timer )
Get timer interrupt status
Parameters
timer
is the instance of the Timer_A module. Valid parameters vary from part to part, but can
include:
TIMER_A0_BASE
TIMER_A1_BASE
TIMER_A2_BASE
TIMER_A3_BASE
Returns
uint32_t. Return interrupt status. Valid values are
TIMER_A_INTERRUPT_PENDING
TIMER_A_INTERRUPT_NOT_PENDING
Referenced by Timer_A_getEnabledInterruptStatus().
24.4.2.18 uint_fast8_t Timer_A_getOutputForOutputModeOutBitValue ( uint32_t timer,
uint_fast16_t captureCompareRegister )
Get ouput bit for output mode
Thu Jan 21 2016 12:34:41 AM
353
16-Bit Timer with Precision PWM (Timer_A)
Parameters
timer
is the instance of the Timer_A module. Valid parameters vary from part to part, but can
include:
TIMER_A0_BASE
TIMER_A1_BASE
TIMER_A2_BASE
TIMER_A3_BASE
captureCompareRegister
selects the Capture register being used. Valid values are
TIMER_A_CAPTURECOMPARE_REGISTER_0
TIMER_A_CAPTURECOMPARE_REGISTER_1
TIMER_A_CAPTURECOMPARE_REGISTER_2
TIMER_A_CAPTURECOMPARE_REGISTER_3
TIMER_A_CAPTURECOMPARE_REGISTER_4
TIMER_A_CAPTURECOMPARE_REGISTER_5
TIMER_A_CAPTURECOMPARE_REGISTER_6
Refer to datasheet to ensure the device has the capture compare register being used
Returns
TIMER_A_OUTPUTMODE_OUTBITVALUE_HIGH or
TIMER_A_OUTPUTMODE_OUTBITVALUE_LOW
24.4.2.19 uint_fast8_t Timer_A_getSynchronizedCaptureCompareInput ( uint32_t timer,
uint_fast16_t captureCompareRegister, uint_fast16_t synchronizedSetting )
Get synchronized capture compare input
Parameters
timer
is the instance of the Timer_A module. Valid parameters vary from part to part, but can
include:
TIMER_A0_BASE
TIMER_A1_BASE
TIMER_A2_BASE
TIMER_A3_BASE
Thu Jan 21 2016 12:34:41 AM
354
16-Bit Timer with Precision PWM (Timer_A)
captureCompareRegister
selects the Capture register being used. Valid values are
TIMER_A_CAPTURECOMPARE_REGISTER_0
TIMER_A_CAPTURECOMPARE_REGISTER_1
TIMER_A_CAPTURECOMPARE_REGISTER_2
TIMER_A_CAPTURECOMPARE_REGISTER_3
TIMER_A_CAPTURECOMPARE_REGISTER_4
TIMER_A_CAPTURECOMPARE_REGISTER_5
TIMER_A_CAPTURECOMPARE_REGISTER_6
Refer to datasheet to ensure the device has the capture compare register being used
synchronizedSetting
is to select type of capture compare input. Valid values are
TIMER_A_READ_CAPTURE_COMPARE_INPUT
TIMER_A_READ_SYNCHRONIZED_CAPTURECOMPAREINPUT
Returns
TIMER_A_CAPTURECOMPARE_INPUT_HIGH or
TIMER_A_CAPTURECOMPARE_INPUT_LOW
24.4.2.20 void Timer_A_initCapture ( uint32_t timer, const Timer_A_CaptureModeConfig
∗ config )
Initializes Capture Mode
Parameters
timer
is the instance of the Timer_A module. Valid parameters vary from part to part, but can
include:
TIMER_A0_BASE
TIMER_A1_BASE
TIMER_A2_BASE
TIMER_A3_BASE
config
Configuration structure for Timer_A capture mode
Configuration options for Timer_A_CaptureModeConfig structure.
Thu Jan 21 2016 12:34:41 AM
355
16-Bit Timer with Precision PWM (Timer_A)
Parameters
captureRegister
selects the Capture register being used. Valid values are
TIMER_A_CAPTURECOMPARE_REGISTER_0
TIMER_A_CAPTURECOMPARE_REGISTER_1
TIMER_A_CAPTURECOMPARE_REGISTER_2
TIMER_A_CAPTURECOMPARE_REGISTER_3
TIMER_A_CAPTURECOMPARE_REGISTER_4
TIMER_A_CAPTURECOMPARE_REGISTER_5
TIMER_A_CAPTURECOMPARE_REGISTER_6
Refer to datasheet to ensure the device has the capture compare register being used
captureMode
is the capture mode selected. Valid values are
TIMER_A_CAPTUREMODE_NO_CAPTURE [Default value]
TIMER_A_CAPTUREMODE_RISING_EDGE
TIMER_A_CAPTUREMODE_FALLING_EDGE
TIMER_A_CAPTUREMODE_RISING_AND_FALLING_EDGE
captureInputSelect
decides the Input Select
TIMER_A_CAPTURE_INPUTSELECT_CCIxA [Default value]
TIMER_A_CAPTURE_INPUTSELECT_CCIxB
TIMER_A_CAPTURE_INPUTSELECT_GND
TIMER_A_CAPTURE_INPUTSELECT_Vcc
synchronizeCaptureSource
decides if capture source should be synchronized with timer clock Valid values are
TIMER_A_CAPTURE_ASYNCHRONOUS [Default value]
TIMER_A_CAPTURE_SYNCHRONOUS
captureInterruptEnable
is to enable or disable timer captureComapre interrupt. Valid values are
TIMER_A_CAPTURECOMPARE_INTERRUPT_DISABLE [Default value]
TIMER_A_CAPTURECOMPARE_INTERRUPT_ENABLE
captureOutputMode
specifies the ouput mode. Valid values are
TIMER_A_OUTPUTMODE_OUTBITVALUE [Default value],
TIMER_A_OUTPUTMODE_SET,
TIMER_A_OUTPUTMODE_TOGGLE_RESET,
TIMER_A_OUTPUTMODE_SET_RESET
TIMER_A_OUTPUTMODE_TOGGLE,
TIMER_A_OUTPUTMODE_RESET,
TIMER_A_OUTPUTMODE_TOGGLE_SET,
TIMER_A_OUTPUTMODE_RESET_SET
Thu Jan 21 2016 12:34:41 AM
356
16-Bit Timer with Precision PWM (Timer_A)
Returns
None
24.4.2.21 void Timer_A_initCompare ( uint32_t timer, const
Timer_A_CompareModeConfig ∗ config )
Initializes Compare Mode
Parameters
timer
is the instance of the Timer_A module. Valid parameters vary from part to part, but can
include:
TIMER_A0_BASE
TIMER_A1_BASE
TIMER_A2_BASE
TIMER_A3_BASE
config
Configuration structure for Timer_A compare mode
Configuration options for Timer_A_CompareModeConfig structure.
Parameters
compareRegister
selects the Capture register being used. Valid values are
TIMER_A_CAPTURECOMPARE_REGISTER_0
TIMER_A_CAPTURECOMPARE_REGISTER_1
TIMER_A_CAPTURECOMPARE_REGISTER_2
TIMER_A_CAPTURECOMPARE_REGISTER_3
TIMER_A_CAPTURECOMPARE_REGISTER_4
TIMER_A_CAPTURECOMPARE_REGISTER_5
TIMER_A_CAPTURECOMPARE_REGISTER_6
Refer to datasheet to ensure the device has the capture compare register being used
Thu Jan 21 2016 12:34:41 AM
357
16-Bit Timer with Precision PWM (Timer_A)
compareInterruptEnable
is to enable or disable timer captureComapre interrupt. Valid values are
TIMER_A_CAPTURECOMPARE_INTERRUPT_ENABLE and
TIMER_A_CAPTURECOMPARE_INTERRUPT_DISABLE [Default value]
compareOutputMode
specifies the output mode. Valid values are
TIMER_A_OUTPUTMODE_OUTBITVALUE [Default value],
TIMER_A_OUTPUTMODE_SET,
TIMER_A_OUTPUTMODE_TOGGLE_RESET,
TIMER_A_OUTPUTMODE_SET_RESET
TIMER_A_OUTPUTMODE_TOGGLE,
TIMER_A_OUTPUTMODE_RESET,
TIMER_A_OUTPUTMODE_TOGGLE_SET,
TIMER_A_OUTPUTMODE_RESET_SET
compareValue
is the count to be compared with in compare mode
Returns
None
24.4.2.22 void Timer_A_registerInterrupt ( uint32_t timer, uint_fast8_t interruptSelect,
void(∗)(void) intHandler )
Registers an interrupt handler for the timer capture compare interrupt.
Parameters
timer
is the instance of the Timer_A module. Valid parameters vary from part to part, but can
include:
TIMER_A0_BASE
TIMER_A1_BASE
TIMER_A2_BASE
TIMER_A3_BASE
Thu Jan 21 2016 12:34:41 AM
358
16-Bit Timer with Precision PWM (Timer_A)
interruptSelect
Selects which timer interrupt handler to register. For the timer module, there are two
separate interrupt handlers that can be registered:
TIMER_A_CCR0_INTERRUPT Corresponds to the interrupt for CCR0
TIMER_A_CCRX_AND_OVERFLOW_INTERRUPT Corresponds to the interrupt for
CCR1-6, as well as the overflow interrupt.
intHandler
is a pointer to the function to be called when the timer capture compare interrupt occurs.
This function registers the handler to be called when a timer interrupt occurs. This function
enables the global interrupt in the interrupt controller; specific Timer_Ainterrupts must be enabled
via Timer_A_enableInterrupt(). It is the interrupt handler’s responsibility to clear the interrupt
source via Timer_A_clearCaptureCompareInterrupt().
Returns
None.
References Interrupt_enableInterrupt(), and Interrupt_registerInterrupt().
24.4.2.23 void Timer_A_setCompareValue ( uint32_t timer, uint_fast16_t compareRegister,
uint_fast16_t compareValue )
Sets the value of the capture-compare register
Parameters
timer
is the instance of the Timer_A module. Valid parameters vary from part to part, but can
include:
TIMER_A0_BASE
TIMER_A1_BASE
TIMER_A2_BASE
TIMER_A3_BASE
compareRegister
selects the Capture register being used. Valid values are
TIMER_A_CAPTURECOMPARE_REGISTER_0
TIMER_A_CAPTURECOMPARE_REGISTER_1
TIMER_A_CAPTURECOMPARE_REGISTER_2
TIMER_A_CAPTURECOMPARE_REGISTER_3
TIMER_A_CAPTURECOMPARE_REGISTER_4
TIMER_A_CAPTURECOMPARE_REGISTER_5
TIMER_A_CAPTURECOMPARE_REGISTER_6
Refer to datasheet to ensure the device has the capture compare register being used
Thu Jan 21 2016 12:34:41 AM
359
16-Bit Timer with Precision PWM (Timer_A)
compareValue
is the count to be compared with in compare mode
Returns
None
24.4.2.24 void Timer_A_setOutputForOutputModeOutBitValue ( uint32_t timer,
uint_fast16_t captureCompareRegister, uint_fast8_t outputModeOutBitValue )
Set ouput bit for output mode
Parameters
timer
is the instance of the Timer_A module. Valid parameters vary from part to part, but can
include:
TIMER_A0_BASE
TIMER_A1_BASE
TIMER_A2_BASE
TIMER_A3_BASE
captureCompareRegister
selects the Capture register being used. are
TIMER_A_CAPTURECOMPARE_REGISTER_0
TIMER_A_CAPTURECOMPARE_REGISTER_1
TIMER_A_CAPTURECOMPARE_REGISTER_2
TIMER_A_CAPTURECOMPARE_REGISTER_3
TIMER_A_CAPTURECOMPARE_REGISTER_4
TIMER_A_CAPTURECOMPARE_REGISTER_5
TIMER_A_CAPTURECOMPARE_REGISTER_6
Refer to datasheet to ensure the device has the capture compare register being used
Thu Jan 21 2016 12:34:41 AM
360
16-Bit Timer with Precision PWM (Timer_A)
outputModeOutBitValue
the value to be set for out bit. Valid values are:
TIMER_A_OUTPUTMODE_OUTBITVALUE_HIGH
TIMER_A_OUTPUTMODE_OUTBITVALUE_LOW
Returns
None
24.4.2.25 void Timer_A_startCounter ( uint32_t timer, uint_fast16_t timerMode )
Starts Timer_A counter
Parameters
timer
is the instance of the Timer_A module. Valid parameters vary from part to part, but can
include:
TIMER_A0_BASE
TIMER_A1_BASE
TIMER_A2_BASE
TIMER_A3_BASE
timerMode
selects Clock source. Valid values are
TIMER_A_CONTINUOUS_MODE [Default value]
TIMER_A_UPDOWN_MODE
TIMER_A_UP_MODE
Note
This function assumes that the timer has been previously configured using
Timer_A_configureContinuousMode, Timer_A_configureUpMode or
Timer_A_configureUpDownMode.
Thu Jan 21 2016 12:34:41 AM
361
16-Bit Timer with Precision PWM (Timer_A)
Returns
None
24.4.2.26 void Timer_A_stopTimer ( uint32_t timer )
Stops the timer
Parameters
timer
is the instance of the Timer_A module. Valid parameters vary from part to part, but can
include:
TIMER_A0_BASE
TIMER_A1_BASE
TIMER_A2_BASE
TIMER_A3_BASE
Returns
None
24.4.2.27 void Timer_A_unregisterInterrupt ( uint32_t timer, uint_fast8_t interruptSelect )
Unregisters the interrupt handler for the timer
Parameters
timer
is the instance of the Timer_A module. Valid parameters vary from part to part, but can
include:
TIMER_A0_BASE
TIMER_A1_BASE
TIMER_A2_BASE
TIMER_A3_BASE
interruptSelect
Selects which timer interrupt handler to register. For the timer module, there are two
separate interrupt handlers that can be registered:
TIMER_A_CCR0_INTERRUPT Corresponds to the interrupt for CCR0
TIMER_A_CCRX_AND_OVERFLOW_INTERRUPT Corresponds to the interrupt for
CCR1-6, as well as the overflow interrupt.
This function unregisters the handler to be called when timer interrupt occurs. This function also
masks off the interrupt in the interrupt controller so that the interrupt handler no longer is called.
See Also
Interrupt_registerInterrupt() for important information about registering interrupt handlers.
Thu Jan 21 2016 12:34:41 AM
362
16-Bit Timer with Precision PWM (Timer_A)
Returns
None.
References Interrupt_disableInterrupt(), and Interrupt_unregisterInterrupt().
Thu Jan 21 2016 12:34:41 AM
363
Universal Asynchronous Receiver/Transmitter (UART)
25
Universal Asynchronous
Receiver/Transmitter (UART)
Module Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .364
Programming Example . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .365
Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 366
25.1
Module Operation
The MSPWare library for UART mode features include:
Odd, even, or non-parity
Independent transmit and receive shift registers
Separate transmit and receive buffer registers
LSB-first or MSB-first data transmit and receive
Built-in idle-line and address-bit communication protocols for multiprocessor systems
Status flags for error detection and suppression
Status flags for address detection
Independent interrupt capability for receive and transmit
The modes of operations supported by the UART and the library include
UART mode
Idle-line multiprocessor mode
Address-bit multiprocessor mode
UART mode with automatic baud-rate detection
In UART mode, the USCI transmits and receives characters at a bit rate asynchronous to another
device. Timing for each character is based on the selected baud rate of the USCI. The transmit
and receive functions use the same baud-rate frequency.
Thu Jan 21 2016 12:34:41 AM
364
Universal Asynchronous Receiver/Transmitter (UART)
25.2
Programming Example
The DriverLib package contains a variety of different code examples that demonstrate the usage
of the UART module. These code examples are accessible under the examples/ folder of the
MSPWare release as well as through TI Resource Explorer if using Code Composer Studio.
These code examples provide a comprehensive list of use cases as well as practical applications
involving each module.
Below is a very brief code example showing how to configure and enable the UART module. In the
case of this example, we assume the MCLK is operating off of the DCO and the DCO is tuned to
12MHz. This makes the configuration parameters so that the baud rate is 9600.
Below is an example of the UART configuration parameter:
/* UART Configuration Parameter. These are the configuration parameters to
* make the eUSCI A UART module to operate with a 9600 baud rate. These
* values were calculated using the online calculator that TI provides
* at:
*http://software-dl.ti.com/msp430/msp430_public_sw/mcu/msp430/MSP430BaudRateConverter/index.html
*/
const eUSCI_UART_Config uartConfig =
{
EUSCI_A_UART_CLOCKSOURCE_SMCLK,
// SMCLK Clock Source
78,
// BRDIV = 78
2,
// UCxBRF = 2
0,
// UCxBRS = 0
EUSCI_A_UART_NO_PARITY,
// No Parity
EUSCI_A_UART_LSB_FIRST,
// LSB First
EUSCI_A_UART_ONE_STOP_BIT,
// One stop bit
EUSCI_A_UART_MODE,
// UART mode
EUSCI_A_UART_OVERSAMPLING_BAUDRATE_GENERATION // Oversampling
};
This code snippet is the actual configuration of the UART module using the DriverLib APIs:
/* Configuring UART Module */
MAP_UART_initModule(EUSCI_A0_BASE,
&uartConfig);
/* Enable UART module */
MAP_UART_enableModule(EUSCI_A0_BASE);
/* Enabling interrupts */
MAP_UART_enableInterrupt(EUSCI_A0_BASE, EUSCI_A_UART_RECEIVE_INTERRUPT);
MAP_Interrupt_enableInterrupt(INT_EUSCIA0);
MAP_Interrupt_enableSleepOnIsrExit();
MAP_Interrupt_enableMaster();
Thu Jan 21 2016 12:34:41 AM
365
Universal Asynchronous Receiver/Transmitter (UART)
25.3
Definitions
Data Structures
struct _eUSCI_eUSCI_UART_Config
Functions
void UART_clearInterruptFlag (uint32_t moduleInstance, uint_fast8_t mask)
void UART_disableInterrupt (uint32_t moduleInstance, uint_fast8_t mask)
void UART_disableModule (uint32_t moduleInstance)
void UART_enableInterrupt (uint32_t moduleInstance, uint_fast8_t mask)
void UART_enableModule (uint32_t moduleInstance)
uint_fast8_t UART_getEnabledInterruptStatus (uint32_t moduleInstance)
uint_fast8_t UART_getInterruptStatus (uint32_t moduleInstance, uint8_t mask)
uint32_t UART_getReceiveBufferAddressForDMA (uint32_t moduleInstance)
uint32_t UART_getTransmitBufferAddressForDMA (uint32_t moduleInstance)
bool UART_initModule (uint32_t moduleInstance, const eUSCI_UART_Config ∗config)
uint_fast8_t UART_queryStatusFlags (uint32_t moduleInstance, uint_fast8_t mask)
uint8_t UART_receiveData (uint32_t moduleInstance)
void UART_registerInterrupt (uint32_t moduleInstance, void(∗intHandler)(void))
void UART_resetDormant (uint32_t moduleInstance)
void UART_selectDeglitchTime (uint32_t moduleInstance, uint32_t deglitchTime)
void UART_setDormant (uint32_t moduleInstance)
void UART_transmitAddress (uint32_t moduleInstance, uint_fast8_t transmitAddress)
void UART_transmitBreak (uint32_t moduleInstance)
void UART_transmitData (uint32_t moduleInstance, uint_fast8_t transmitData)
void UART_unregisterInterrupt (uint32_t moduleInstance)
25.3.1 Detailed Description
The code for this module is contained in uart/adc14.c, with driverlib/uart.h containing
the API declarations for use by applications.
Thu Jan 21 2016 12:34:41 AM
366
Universal Asynchronous Receiver/Transmitter (UART)
25.3.2 Function Documentation
25.3.2.1 void UART_clearInterruptFlag ( uint32_t moduleInstance, uint_fast8_t mask )
Clears UART interrupt sources.
Parameters
moduleInstance
is the instance of the eUSCI A (UART) module. Valid parameters vary from part to part,
but can include:
EUSCI_A0_BASE
EUSCI_A1_BASE
EUSCI_A2_BASE
EUSCI_A3_BASE
It is important to note that for eUSCI modules, only "A" modules such as EUSCI_A0
can be used. "B" modules such as EUSCI_B0 do not support the UART mode
mask
is a bit mask of the interrupt sources to be cleared.
The UART interrupt source is cleared, so that it no longer asserts. The highest interrupt flag is
automatically cleared when an interrupt vector generator is used.
The mask parameter has the same definition as the mask parameter to
EUSCI_A_UART_enableInterrupt().
Modified register is UCAxIFG
Returns
None.
25.3.2.2 void UART_disableInterrupt ( uint32_t moduleInstance, uint_fast8_t mask )
Disables individual UART interrupt sources.
Parameters
moduleInstance
is the instance of the eUSCI A (UART) module. Valid parameters vary from part to part,
but can include:
EUSCI_A0_BASE
EUSCI_A1_BASE
EUSCI_A2_BASE
EUSCI_A3_BASE
It is important to note that for eUSCI modules, only "A" modules such as EUSCI_A0
can be used. "B" modules such as EUSCI_B0 do not support the UART mode
Thu Jan 21 2016 12:34:41 AM
367
Universal Asynchronous Receiver/Transmitter (UART)
mask
is the bit mask of the interrupt sources to be disabled.
Disables the indicated UART interrupt sources. Only the sources that are enabled can be reflected
to the processor interrupt; disabled sources have no effect on the processor.
The mask parameter is the logical OR of any of the following:
EUSCI_A_UART_RECEIVE_INTERRUPT -Receive interrupt
EUSCI_A_UART_TRANSMIT_INTERRUPT - Transmit interrupt
EUSCI_A_UART_RECEIVE_ERRONEOUSCHAR_INTERRUPT - Receive
erroneous-character interrupt enable
EUSCI_A_UART_BREAKCHAR_INTERRUPT - Receive break character interrupt enable
Modified register is UCAxIFG, UCAxIE and UCAxCTL1
Returns
None.
25.3.2.3 void UART_disableModule ( uint32_t moduleInstance )
Disables the UART block.
Parameters
moduleInstance
is the instance of the eUSCI A (UART) module. Valid parameters vary from part to part,
but can include:
EUSCI_A0_BASE
EUSCI_A1_BASE
EUSCI_A2_BASE
EUSCI_A3_BASE
It is important to note that for eUSCI modules, only "A" modules such as EUSCI_A0
can be used. "B" modules such as EUSCI_B0 do not support the UART mode
This will disable operation of the UART block.
Modified register is UCAxCTL1
Returns
None.
25.3.2.4 void UART_enableInterrupt ( uint32_t moduleInstance, uint_fast8_t mask )
Enables individual UART interrupt sources.
Parameters
Thu Jan 21 2016 12:34:41 AM
368
Universal Asynchronous Receiver/Transmitter (UART)
moduleInstance
is the instance of the eUSCI A (UART) module. Valid parameters vary from part to part,
but can include:
EUSCI_A0_BASE
EUSCI_A1_BASE
EUSCI_A2_BASE
EUSCI_A3_BASE
It is important to note that for eUSCI modules, only "A" modules such as EUSCI_A0
can be used. "B" modules such as EUSCI_B0 do not support the UART mode
mask
is the bit mask of the interrupt sources to be enabled.
Enables the indicated UART interrupt sources. The interrupt flag is first and then the
corresponding interrupt is enabled. Only the sources that are enabled can be reflected to the
processor interrupt; disabled sources have no effect on the processor.
The mask parameter is the logical OR of any of the following:
EUSCI_A_UART_RECEIVE_INTERRUPT -Receive interrupt
EUSCI_A_UART_TRANSMIT_INTERRUPT - Transmit interrupt
EUSCI_A_UART_RECEIVE_ERRONEOUSCHAR_INTERRUPT - Receive
erroneous-character interrupt enable
EUSCI_A_UART_BREAKCHAR_INTERRUPT - Receive break character interrupt enable
Modified register is UCAxIFG, UCAxIE and UCAxCTL1
Returns
None.
25.3.2.5 void UART_enableModule ( uint32_t moduleInstance )
Enables the UART block.
Parameters
moduleInstance
is the instance of the eUSCI A (UART) module. Valid parameters vary from part to part,
but can include:
EUSCI_A0_BASE
EUSCI_A1_BASE
EUSCI_A2_BASE
EUSCI_A3_BASE
It is important to note that for eUSCI modules, only "A" modules such as EUSCI_A0
can be used. "B" modules such as EUSCI_B0 do not support the UART mode
This will enable operation of the UART block.
Modified register is UCAxCTL1
Returns
None.
Thu Jan 21 2016 12:34:41 AM
369
Universal Asynchronous Receiver/Transmitter (UART)
25.3.2.6 uint_fast8_t UART_getEnabledInterruptStatus ( uint32_t moduleInstance )
Gets the current UART interrupt status masked with the enabled interrupts. This function is useful
to call in ISRs to get a list of pending interrupts that are actually enabled and could have caused
the ISR.
Parameters
moduleInstance
is the instance of the eUSCI A (UART) module. Valid parameters vary from part to part,
but can include:
EUSCI_A0_BASE
EUSCI_A1_BASE
EUSCI_A2_BASE
EUSCI_A3_BASE
It is important to note that for eUSCI modules, only "A" modules such as EUSCI_A0
can be used. "B" modules such as EUSCI_B0 do not support the UART mode
Returns
The current interrupt status as an ORed bit mask:
EUSCI_A_UART_RECEIVE_INTERRUPT_FLAG -Receive interrupt flag
EUSCI_A_UART_TRANSMIT_INTERRUPT_FLAG - Transmit interrupt flag
References UART_getInterruptStatus().
25.3.2.7 uint_fast8_t UART_getInterruptStatus ( uint32_t moduleInstance, uint8_t mask )
Gets the current UART interrupt status.
Parameters
moduleInstance
is the instance of the eUSCI A (UART) module. Valid parameters vary from part to part,
but can include:
EUSCI_A0_BASE
EUSCI_A1_BASE
EUSCI_A2_BASE
EUSCI_A3_BASE
It is important to note that for eUSCI modules, only "A" modules such as EUSCI_A0
can be used. "B" modules such as EUSCI_B0 do not support the UART mode
mask
is the masked interrupt flag status to be returned. Mask value is the logical OR of any of
the following:
EUSCI_A_UART_RECEIVE_INTERRUPT_FLAG
EUSCI_A_UART_TRANSMIT_INTERRUPT_FLAG
EUSCI_A_UART_STARTBIT_INTERRUPT_FLAG
EUSCI_A_UART_TRANSMIT_COMPLETE_INTERRUPT_FLAG
Thu Jan 21 2016 12:34:41 AM
370
Universal Asynchronous Receiver/Transmitter (UART)
Returns
The current interrupt status as an ORed bit mask:
EUSCI_A_UART_RECEIVE_INTERRUPT_FLAG -Receive interrupt flag
EUSCI_A_UART_TRANSMIT_INTERRUPT_FLAG - Transmit interrupt flag
Referenced by UART_getEnabledInterruptStatus().
25.3.2.8 uint32_t UART_getReceiveBufferAddressForDMA ( uint32_t moduleInstance )
Returns the address of the RX Buffer of the UART for the DMA module.
Parameters
moduleInstance
is the instance of the eUSCI A (UART) module. Valid parameters vary from part to part,
but can include:
EUSCI_A0_BASE
EUSCI_A1_BASE
EUSCI_A2_BASE
EUSCI_A3_BASE
It is important to note that for eUSCI modules, only "A" modules such as EUSCI_A0
can be used. "B" modules such as EUSCI_B0 do not support the UART mode
Returns the address of the UART RX Buffer. This can be used in conjunction with the DMA to
store the received data directly to memory.
Returns
None
25.3.2.9 uint32_t UART_getTransmitBufferAddressForDMA ( uint32_t moduleInstance )
Returns the address of the TX Buffer of the UART for the DMA module.
Parameters
moduleInstance
is the instance of the eUSCI A (UART) module. Valid parameters vary from part to part,
but can include:
EUSCI_A0_BASE
EUSCI_A1_BASE
EUSCI_A2_BASE
EUSCI_A3_BASE
It is important to note that for eUSCI modules, only "A" modules such as EUSCI_A0
can be used. "B" modules such as EUSCI_B0 do not support the UART mode
Returns the address of the UART TX Buffer. This can be used in conjunction with the DMA to
obtain transmitted data directly from memory.
Thu Jan 21 2016 12:34:41 AM
371
Universal Asynchronous Receiver/Transmitter (UART)
Returns
None
25.3.2.10 bool UART_initModule ( uint32_t moduleInstance, const eUSCI_UART_Config ∗
config )
Initialization routine for the UART block. The values to be written into the UCAxBRW and
UCAxMCTLW registers should be pre-computed and passed into the initialization function
Parameters
moduleInstance
is the instance of the eUSCI A (UART) module. Valid parameters vary from part to part,
but can include:
EUSCI_A0_BASE
EUSCI_A1_BASE
EUSCI_A2_BASE
EUSCI_A3_BASE
config
Configuration structure for the UART module
Configuration options for eUSCI_UART_Config structure.
It is important to note that for eUSCI modules, only "A" modules such as EUSCI_A0 can be used.
"B" modules such as EUSCI_B0 do not support the UART mode.
Parameters
selectClockSource
selects Clock source. Valid values are
EUSCI_A_UART_CLOCKSOURCE_SMCLK
EUSCI_A_UART_CLOCKSOURCE_ACLK
clockPrescalar
firstModReg
secondModReg
parity
is the value to be written into UCBRx bits
is First modulation stage register setting. This value is a pre-calculated value which can
be obtained from the Device User Guide.This value is written into UCBRFx bits of UCAxMCTLW.
is Second modulation stage register setting. This value is a pre-calculated value which
can be obtained from the Device User Guide. This value is written into UCBRSx bits of
UCAxMCTLW.
is the desired parity. Valid values are
EUSCI_A_UART_NO_PARITY [Default Value],
EUSCI_A_UART_ODD_PARITY,
EUSCI_A_UART_EVEN_PARITY
Thu Jan 21 2016 12:34:41 AM
372
Universal Asynchronous Receiver/Transmitter (UART)
msborLsbFirst
controls direction of receive and transmit shift register. Valid values are
EUSCI_A_UART_MSB_FIRST
EUSCI_A_UART_LSB_FIRST [Default Value]
numberofStopBits
indicates one/two STOP bits Valid values are
EUSCI_A_UART_ONE_STOP_BIT [Default Value]
EUSCI_A_UART_TWO_STOP_BITS
uartMode
selects the mode of operation Valid values are
EUSCI_A_UART_MODE [Default Value],
EUSCI_A_UART_IDLE_LINE_MULTI_PROCESSOR_MODE,
EUSCI_A_UART_ADDRESS_BIT_MULTI_PROCESSOR_MODE,
EUSCI_A_UART_AUTOMATIC_BAUDRATE_DETECTION_MODE
overSampling
indicates low frequency or oversampling baud generation Valid values are
EUSCI_A_UART_OVERSAMPLING_BAUDRATE_GENERATION
EUSCI_A_UART_LOW_FREQUENCY_BAUDRATE_GENERATION
Upon successful initialization of the UART block, this function will have initialized the module, but
the UART block still remains disabled and must be enabled with UART_enableModule()
Refer to this calculator for help on calculating values for the parameters.
Modified bits are UCPEN, UCPAR, UCMSB, UC7BIT, UCSPB, UCMODEx, UCSYNC bits of
UCAxCTL0 and UCSSELx, UCSWRST bits of UCAxCTL1
Returns
true or STATUS_FAIL of the initialization process
25.3.2.11 uint_fast8_t UART_queryStatusFlags ( uint32_t moduleInstance, uint_fast8_t
mask )
Gets the current UART status flags.
Parameters
moduleInstance
is the instance of the eUSCI A (UART) module. Valid parameters vary from part to part,
but can include:
EUSCI_A0_BASE
EUSCI_A1_BASE
EUSCI_A2_BASE
EUSCI_A3_BASE
It is important to note that for eUSCI modules, only "A" modules such as EUSCI_A0
can be used. "B" modules such as EUSCI_B0 do not support the UART mode
mask
is the masked interrupt flag status to be returned.
This returns the status for the UART module based on which flag is passed. mask parameter can
Thu Jan 21 2016 12:34:41 AM
373
Universal Asynchronous Receiver/Transmitter (UART)
be either any of the following selection.
EUSCI_A_UART_LISTEN_ENABLE
EUSCI_A_UART_FRAMING_ERROR
EUSCI_A_UART_OVERRUN_ERROR
EUSCI_A_UART_PARITY_ERROR
eUARTBREAK_DETECT
EUSCI_A_UART_RECEIVE_ERROR
EUSCI_A_UART_ADDRESS_RECEIVED
EUSCI_A_UART_IDLELINE
EUSCI_A_UART_BUSY
Modified register is UCAxSTAT
Returns
the masked status flag
25.3.2.12 uint8_t UART_receiveData ( uint32_t moduleInstance )
Receives a byte that has been sent to the UART Module.
Parameters
moduleInstance
is the instance of the eUSCI A (UART) module. Valid parameters vary from part to part,
but can include:
EUSCI_A0_BASE
EUSCI_A1_BASE
EUSCI_A2_BASE
EUSCI_A3_BASE
It is important to note that for eUSCI modules, only "A" modules such as EUSCI_A0
can be used. "B" modules such as EUSCI_B0 do not support the UART mode
This function reads a byte of data from the UART receive data Register.
Modified register is UCAxRXBUF
Returns
Returns the byte received from by the UART module, cast as an uint8_t.
25.3.2.13 void UART_registerInterrupt ( uint32_t moduleInstance, void(∗)(void) intHandler
)
Registers an interrupt handler for UART interrupts.
Thu Jan 21 2016 12:34:41 AM
374
Universal Asynchronous Receiver/Transmitter (UART)
Parameters
moduleInstance
is the instance of the eUSCI A (UART) module. Valid parameters vary from part to part,
but can include:
EUSCI_A0_BASE
EUSCI_A1_BASE
EUSCI_A2_BASE
EUSCI_A3_BASE
It is important to note that for eUSCI modules, only "A" modules such as EUSCI_A0
can be used. "B" modules such as EUSCI_B0 do not support the UART mode.
intHandler
is a pointer to the function to be called when the timer capture compare interrupt occurs.
This function registers the handler to be called when an UART interrupt occurs. This function
enables the global interrupt in the interrupt controller; specific UART interrupts must be enabled
via UART_enableInterrupt(). It is the interrupt handler’s responsibility to clear the interrupt source
via UART_clearInterruptFlag().
Returns
None.
References Interrupt_enableInterrupt(), and Interrupt_registerInterrupt().
25.3.2.14 void UART_resetDormant ( uint32_t moduleInstance )
Re-enables UART module from dormant mode
Parameters
moduleInstance
is the instance of the eUSCI A (UART) module. Valid parameters vary from part to part,
but can include:
EUSCI_A0_BASE
EUSCI_A1_BASE
EUSCI_A2_BASE
EUSCI_A3_BASE
It is important to note that for eUSCI modules, only "A" modules such as EUSCI_A0
can be used. "B" modules such as EUSCI_B0 do not support the UART mode
Not dormant. All received characters set UCRXIFG.
Modified bits are UCDORM of UCAxCTL1 register.
Returns
None.
25.3.2.15 void UART_selectDeglitchTime ( uint32_t moduleInstance, uint32_t deglitchTime
)
Sets the deglitch time
Thu Jan 21 2016 12:34:41 AM
375
Universal Asynchronous Receiver/Transmitter (UART)
Parameters
moduleInstance
is the instance of the eUSCI A (UART) module. Valid parameters vary from part to part,
but can include:
EUSCI_A0_BASE
EUSCI_A1_BASE
EUSCI_A2_BASE
EUSCI_A3_BASE
It is important to note that for eUSCI modules, only "A" modules such as EUSCI_A0
can be used. "B" modules such as EUSCI_B0 do not support the UART mode
deglitchTime
is the selected deglitch time Valid values are
EUSCI_A_UART_DEGLITCH_TIME_2ns
EUSCI_A_UART_DEGLITCH_TIME_50ns
EUSCI_A_UART_DEGLITCH_TIME_100ns
EUSCI_A_UART_DEGLITCH_TIME_200ns
Returns the address of the UART TX Buffer. This can be used in conjunction with the DMA to
obtain transmitted data directly from memory.
Returns
None
25.3.2.16 void UART_setDormant ( uint32_t moduleInstance )
Sets the UART module in dormant mode
Parameters
moduleInstance
is the instance of the eUSCI A (UART) module. Valid parameters vary from part to part,
but can include:
EUSCI_A0_BASE
EUSCI_A1_BASE
EUSCI_A2_BASE
EUSCI_A3_BASE
It is important to note that for eUSCI modules, only "A" modules such as EUSCI_A0
can be used. "B" modules such as EUSCI_B0 do not support the UART mode
Puts USCI in sleep mode Only characters that are preceded by an idle-line or with address bit set
UCRXIFG. In UART mode with automatic baud-rate detection, only the combination of a break
and synch field sets UCRXIFG.
Modified register is UCAxCTL1
Returns
None.
Thu Jan 21 2016 12:34:41 AM
376
Universal Asynchronous Receiver/Transmitter (UART)
25.3.2.17 void UART_transmitAddress ( uint32_t moduleInstance, uint_fast8_t
transmitAddress )
Transmits the next byte to be transmitted marked as address depending on selected
multiprocessor mode
Thu Jan 21 2016 12:34:41 AM
377
Universal Asynchronous Receiver/Transmitter (UART)
Parameters
moduleInstance
is the instance of the eUSCI A (UART) module. Valid parameters vary from part to part,
but can include:
EUSCI_A0_BASE
EUSCI_A1_BASE
EUSCI_A2_BASE
EUSCI_A3_BASE
It is important to note that for eUSCI modules, only "A" modules such as EUSCI_A0
can be used. "B" modules such as EUSCI_B0 do not support the UART mode
transmitAddress
is the next byte to be transmitted
Modified register is UCAxCTL1, UCAxTXBUF
Returns
None.
25.3.2.18 void UART_transmitBreak ( uint32_t moduleInstance )
Transmit break. Transmits a break with the next write to the transmit buffer. In UART mode with
automatic baud-rate detection, EUSCI_A_UART_AUTOMATICBAUDRATE_SYNC(0x55) must be
written into UCAxTXBUF to generate the required break/synch fields. Otherwise,
DEFAULT_SYNC(0x00) must be written into the transmit buffer. Also ensures module is ready for
transmitting the next data
Parameters
moduleInstance
is the instance of the eUSCI A (UART) module. Valid parameters vary from part to part,
but can include:
EUSCI_A0_BASE
EUSCI_A1_BASE
EUSCI_A2_BASE
EUSCI_A3_BASE
It is important to note that for eUSCI modules, only "A" modules such asEUSCI_A0
can be used. "B" modules such as EUSCI_B0 do not support the UART mode
Modified register is UCAxCTL1, UCAxTXBUF
Returns
None.
25.3.2.19 void UART_transmitData ( uint32_t moduleInstance, uint_fast8_t transmitData )
Transmits a byte from the UART Module.
Thu Jan 21 2016 12:34:41 AM
378
Universal Asynchronous Receiver/Transmitter (UART)
Parameters
moduleInstance
is the instance of the eUSCI A (UART) module. Valid parameters vary from part to part,
but can include:
EUSCI_A0_BASE
EUSCI_A1_BASE
EUSCI_A2_BASE
EUSCI_A3_BASE
It is important to note that for eUSCI modules, only "A" modules such as EUSCI_A0
can be used. "B" modules such as EUSCI_B0 do not support the UART mode
transmitData
data to be transmitted from the UART module
This function will place the supplied data into UART transmit data register to start transmission
Modified register is UCAxTXBUF
Returns
None.
25.3.2.20 void UART_unregisterInterrupt ( uint32_t moduleInstance )
Unregisters the interrupt handler for the UART module
Parameters
moduleInstance
is the instance of the eUSCI A (UART) module. Valid parameters vary from part to part,
but can include:
EUSCI_A0_BASE
EUSCI_A1_BASE
EUSCI_A2_BASE
EUSCI_A3_BASE
It is important to note that for eUSCI modules, only "A" modules such as EUSCI_A0
can be used. "B" modules such as EUSCI_B0 do not support the UART mode.
Thu Jan 21 2016 12:34:41 AM
379
Universal Asynchronous Receiver/Transmitter (UART)
This function unregisters the handler to be called when timer interrupt occurs. This function also
masks off the interrupt in the interrupt controller so that the interrupt handler no longer is called.
See Also
Interrupt_registerInterrupt() for important information about registering interrupt handlers.
Returns
None.
References Interrupt_disableInterrupt(), and Interrupt_unregisterInterrupt().
Thu Jan 21 2016 12:34:41 AM
380
Watchdog Timer (WDT_A)
26
Watchdog Timer (WDT_A)
Module Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .381
Watchdog Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 381
Interval Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 381
Setting Reset Type . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .382
Programming Example . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .382
Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 383
26.1
Module Operation
MSP432 includes a standard watchdog module that is identical to the WDT_A module of MSP430.
By using DriverLib, the user can configure all aspects of the watchdog peripheral including using
the watchdog in interval mode as well as watchdog mode.
26.2
Watchdog Mode
Once the module is initiated in watchdog mode, the timer will reset part if the count expires. The
reset can be set as either a soft or hard reset. This use case is useful when the programmer wants
to make sure that the code execution isn’t perpetually stuck/locked in an unrecoverable state.
To configure the WDT module in watchdog mode, the WDT_initWatchdogTimer function is used
such as follows:
/* Configuring WDT to timeout after 512k iterations of SMCLK,
* this will roughly equal 4 seconds*/
MAP_SysCtl_setWDTTimeoutResetType(SYSCTL_SOFT_RESET);
MAP_WDT_A_initWatchdogTimer(WDT_A_CLOCKSOURCE_SMCLK,
WDT_A_CLOCKITERATIONS_512K);
at 128k,
This will set the watchdog timer to be sourced from SMCLK and have a duration of 512, 000
SMCLK cycles. This means that once started, if the watchdog timer goes 512, 000 iterations
without being reset a reset will occur. To reset the counter (after using WDT_startTimer to start the
timer), the user should use the WDT_resetTimer function.
26.3
Interval Mode
MSP432 Driverlib can also configure the WDT module to work in interval mode. This turns the
WDT into an ordinary 16-bit down counter with interrupt support. This can be used if the user
needs access to another low power counter, however has already used other resources. To
configure the module in interval mode, use the WDT_initIntervalTimer function such as follows:
/* Configuring WDT in interval mode to trigger every 32K clock iterations.
* This comes out to roughly every 3.5 seconds */
MAP_WDT_A_initIntervalTimer(WDT_A_CLOCKSOURCE_VLOCLK,
WDT_A_CLOCKITERATIONS_32K);
Thu Jan 21 2016 12:34:41 AM
381
Watchdog Timer (WDT_A)
This will configure the WDT module to be sourced from SMCLK and have a period of 32, 000
cycles. In this example, we have previously configured SMCLK to be 64Khz making this timer’s
period be approximately half a second. After using the WDT_startTimer function to start the timer,
the user can service interrupts from interval mode after enabling interrupts using the
Interrupt_enableInterrupt function.
26.4
Setting Reset Type
The type of reset that occurs on watchdog timeout/password violation can be configured through
the SysCtl module using the SysCtl_setWDTPasswordViolationResetType and
SysCtl_setWDTTimeoutResetType APIs. These APIs will allow the user to change whether a soft
or hard reset occurs on a watchdog timeout and password violation. For the user, the convenience
functions WDT_setPasswordViolationReset and WDT_setTimeoutReset exist in the WDT APIs.
26.5
Programming Example
The DriverLib package contains a variety of different code examples that demonstrate the usage
of the WDT module. These code examples are accessible under the examples/ folder of the
MSPWare release as well as through TI Resource Explorer if using Code Composer Studio.
These code examples provide a comprehensive list of use cases as well as practical applications
involving each module.
Below is a very brief code example showing how to configure the WDT module in interval mode:
/* Configuring WDT in interval mode to trigger every 32K clock iterations.
* This comes out to roughly every 3.5 seconds */
MAP_WDT_A_initIntervalTimer(WDT_A_CLOCKSOURCE_VLOCLK,
WDT_A_CLOCKITERATIONS_32K);
Thu Jan 21 2016 12:34:41 AM
382
Watchdog Timer (WDT_A)
26.6
Definitions
Functions
void WDT_A_clearTimer (void)
void WDT_A_holdTimer (void)
void WDT_A_initIntervalTimer (uint_fast8_t clockSelect, uint_fast8_t clockDivider)
void WDT_A_initWatchdogTimer (uint_fast8_t clockSelect, uint_fast8_t clockDivider)
void WDT_A_registerInterrupt (void(∗intHandler)(void))
void WDT_A_setPasswordViolationReset (uint_fast8_t resetType)
void WDT_A_setTimeoutReset (uint_fast8_t resetType)
void WDT_A_startTimer (void)
void WDT_A_unregisterInterrupt (void)
26.6.1 Detailed Description
The code for this module is contained in driverlib/wdt.c, with driverlib/wdt.h containing
the API declarations for use by applications.
Thu Jan 21 2016 12:34:41 AM
383
Watchdog Timer (WDT_A)
26.6.2 Function Documentation
26.6.2.1 void WDT_A_clearTimer ( void )
Clears the timer counter of the Watchdog Timer.
This function clears the watchdog timer count to 0x0000h. This function is used to "service the
dog" when operating in watchdog mode.
Returns
None
26.6.2.2 void WDT_A_holdTimer ( void )
Holds the Watchdog Timer.
This function stops the watchdog timer from running. This way no interrupt or PUC is asserted.
Returns
None
Referenced by PCM_gotoLPM4().
26.6.2.3 void WDT_A_initIntervalTimer ( uint_fast8_t clockSelect, uint_fast8_t
clockDivider )
Sets the clock source for the Watchdog Timer in timer interval mode.
Parameters
clockSelect
is the clock source that the watchdog timer will use. Valid values are
WDT_A_CLOCKSOURCE_SMCLK [Default]
WDT_A_CLOCKSOURCE_ACLK
WDT_A_CLOCKSOURCE_VLOCLK
WDT_A_CLOCKSOURCE_BCLK
clockIterations
is the number of clock iterations for a watchdog interval. Valid values are
WDT_A_CLOCKITERATIONS_2G [Default]
WDT_A_CLOCKITERATIONS_128M
WDT_A_CLOCKITERATIONS_8192K
WDT_A_CLOCKITERATIONS_512K
WDT_A_CLOCKITERATIONS_32K
WDT_A_CLOCKITERATIONS_8192
WDT_A_CLOCKITERATIONS_512
WDT_A_CLOCKITERATIONS_64
Thu Jan 21 2016 12:34:41 AM
384
Watchdog Timer (WDT_A)
This function sets the watchdog timer as timer interval mode, which will assert an interrupt without
causing a PUC.
Returns
None
26.6.2.4 void WDT_A_initWatchdogTimer ( uint_fast8_t clockSelect, uint_fast8_t
clockDivider )
Sets the clock source for the Watchdog Timer in watchdog mode.
Parameters
clockSelect
is the clock source that the watchdog timer will use. Valid values are
WDT_A_CLOCKSOURCE_SMCLK [Default]
WDT_A_CLOCKSOURCE_ACLK
WDT_A_CLOCKSOURCE_VLOCLK
WDT_A_CLOCKSOURCE_BCLK
clockIterations
is the number of clock iterations for a watchdog timeout. Valid values are
WDT_A_CLOCKITERATIONS_2G [Default]
WDT_A_CLOCKITERATIONS_128M
WDT_A_CLOCKITERATIONS_8192K
WDT_A_CLOCKITERATIONS_512K
WDT_A_CLOCKITERATIONS_32K
WDT_A_CLOCKITERATIONS_8192
WDT_A_CLOCKITERATIONS_512
WDT_A_CLOCKITERATIONS_64
This function sets the watchdog timer in watchdog mode, which will cause a PUC when the timer
overflows. When in the mode, a PUC can be avoided with a call to WDT_A_resetTimer() before
the timer runs out.
Returns
None
26.6.2.5 void WDT_A_registerInterrupt ( void(∗)(void) intHandler )
Registers an interrupt handler for the watchdog interrupt.
Parameters
intHandler
Thu Jan 21 2016 12:34:41 AM
is a pointer to the function to be called when the watchdog interrupt occurs.
385
Watchdog Timer (WDT_A)
Returns
None.
References Interrupt_enableInterrupt(), and Interrupt_registerInterrupt().
26.6.2.6 void WDT_A_setPasswordViolationReset ( uint_fast8_t resetType )
Sets the type of RESET that happens when a watchdog password violation occurs.
Parameters
resetType
The type of reset to set
The resetType parameter must be only one of the following values:
WDT_A_HARD_RESET
WDT_A_SOFT_RESET
Returns
None.
References SysCtl_setWDTPasswordViolationResetType().
26.6.2.7 void WDT_A_setTimeoutReset ( uint_fast8_t resetType )
Sets the type of RESET that happens when a watchdog timeout occurs.
Parameters
resetType
The type of reset to set
The resetType parameter must be only one of the following values:
WDT_A_HARD_RESET
WDT_A_SOFT_RESET
Returns
None.
References SysCtl_setWDTTimeoutResetType().
26.6.2.8 void WDT_A_startTimer ( void )
Starts the Watchdog Timer.
This function starts the watchdog timer functionality to start counting.
Returns
None
Thu Jan 21 2016 12:34:41 AM
386
Watchdog Timer (WDT_A)
26.6.2.9 void WDT_A_unregisterInterrupt ( void )
Unregisters the interrupt handler for the watchdog.
This function unregisters the handler to be called when a watchdog interrupt occurs. This function
also masks off the interrupt in the interrupt controller so that the interrupt handler no longer is
called.
See Also
Interrupt_registerInterrupt() for important information about registering interrupt handlers.
Returns
None.
References Interrupt_disableInterrupt(), and Interrupt_unregisterInterrupt().
Thu Jan 21 2016 12:34:41 AM
387
IMPORTANT NOTICE
Texas Instruments Incorporated and its subsidiaries (TI) reserve the right to make corrections, enhancements, improvements and other
changes to its semiconductor products and services per JESD46, latest issue, and to discontinue any product or service per JESD48,
latest issue. Buyers should obtain the latest relevant information before placing orders and should verify that such information is current
and complete. All semiconductor products (also referred to herein as “components”) are sold subject to TI’s terms and conditions of sale
supplied at the time of order acknowledgment.
TI warrants performance of its components to the specifications applicable at the time of sale, in accordance with the warranty in TI’s terms
and conditions of sale of semiconductor products. Testing and other quality control techniques are used to the extent TI deems necessary to
support this warranty. Except where mandated by applicable law, testing of all parameters of each component is not necessarily performed.
TI assumes no liability for applications assistance or the design of Buyers’ products. Buyers are responsible for their products and applications using TI components. To minimize the risks associated with Buyers’ products and applications, Buyers should provide adequate
design and operating safeguards.
TI does not warrant or represent that any license, either express or implied, is granted under any patent right, copyright, mask work right, or
other intellectual property right relating to any combination, machine, or process in which TI components or services are used. Information
published by TI regarding third-party products or services does not constitute a license to use such products or services or a warranty or
endorsement thereof. Use of such information may require a license from a third party under the patents or other intellectual property of
the third party, or a license from TI under the patents or other intellectual property of TI.
Reproduction of significant portions of TI information in TI data books or data sheets is permissible only if reproduction is without alteration
and is accompanied by all associated warranties, conditions, limitations, and notices. TI is not responsible or liable for such altered
documentation. Information of third parties may be subject to additional restrictions.
Resale of TI components or services with statements different from or beyond the parameters stated by TI for that component or service
voids all express and any implied warranties for the associated TI component or service and is an unfair and deceptive business practice.
TI is not responsible or liable for any such statements.
Buyer acknowledges and agrees that it is solely responsible for compliance with all legal, regulatory and safety-related requirements
concerning its products, and any use of TI components in its applications, notwithstanding any applications-related information or support
that may be provided by TI. Buyer represents and agrees that it has all the necessary expertise to create and implement safeguards which
anticipate dangerous consequences of failures, monitor failures and their consequences, lessen the likelihood of failures that might cause
harm and take appropriate remedial actions. Buyer will fully indemnify TI and its representatives against any damages arising out of the
use of any TI components in safety-critical applications.
In some cases, TI components may be promoted specifically to facilitate safety-related applications. With such components, TI’s goal
is to help enable customers to design and create their own end-product solutions that meet applicable functional safety standards and
requirements. Nonetheless, such components are subject to these terms.
No TI components are authorized for use in FDA Class III (or similar life-critical medical equipment) unless authorized officers of the parties
have executed a special agreement specifically governing such use.
Only those TI components which TI has specifically designated as military grade or “enhanced plastic” are designed and intended for use
in military/aerospace applications or environments. Buyer acknowledges and agrees that any military or aerospace use of TI components
which have not been so designated is solely at the Buyer’s risk, and that Buyer is solely responsible for compliance with all legal and
regulatory requirements in connection with such use.
TI has specifically designated certain components as meeting ISO/TS16949 requirements, mainly for automotive use. In any case of use
of non-designated products, TI will not be responsible for any failure to meet ISO/TS16949.
Products
Audio
Amplifiers
Data Converters
DLP® Products
DSP
Clocks and Timers
Interface
Logic
Power Mgmt
Microcontrollers
RFID
OMAP Applications Processors
Wireless Connectivity
Applications
Automotive and Transportation
www.ti.com/audio
amplifier.ti.com
Communications and Telecom
dataconverter.ti.com
Computers and Peripherals
www.dlp.com
Consumer Electronics
dsp.ti.com
Energy and Lighting
www.ti.com/clocks
Industrial
interface.ti.com
Medical
logic.ti.com
Security
power.ti.com
Space, Avionics and Defense
microcontroller.ti.com
Video and Imaging
www.ti-rfid.com
www.ti.com/omap
TI E2E Community
www.ti.com/wirelessconnectivity
www.ti.com/automotive
www.ti.com/communications
www.ti.com/computers
www.ti.com/consumer-apps
www.ti.com/energy
www.ti.com/industrial
www.ti.com/medical
www.ti.com/security
www.ti.com/space-avionics-defense
www.ti.com/video
e2e.ti.com
Mailing Address: Texas Instruments, Post Office Box 655303, Dallas, Texas 75265
Copyright © 2016, Texas Instruments Incorporated
Thu Jan 21 2016 12:34:41 AM
388
Source Exif Data:
File Type : PDF File Type Extension : pdf MIME Type : application/pdf PDF Version : 1.5 Linearized : No Page Count : 389 Page Mode : UseNone Author : Copyright © 2016 Texas Instruments Incorporated. All rights reserved. Title : MSP432 User's Guide Subject : Version Creator : LaTeX with hyperref package Producer : pdfTeX-1.40.15 Create Date : 2016:01:21 00:35:42-06:00 Modify Date : 2016:01:21 00:35:42-06:00 Trapped : False PTEX Fullbanner : This is pdfTeX, Version 3.14159265-2.6-1.40.15 (TeX Live 2014/Cygwin) kpathsea version 6.2.0EXIF Metadata provided by EXIF.tools