C Compiler Reference Manual August 2009
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C Compiler
Reference Manual
August 2009
This manual documents software version 4.
Review the readme.txt file in the product directory for changes made since this version.
Copyright © 1994, 2009 Custom Computer Services, Inc.
All rights reserved worldwide. No part of this work may be reproduced or copied in any form or by
any means- electronic, graphic, or mechanical, including photocopying, recording, taping, or
information retrieval systems without prior permission.
Table Of Contents
Overview .......................................................................................................................................... 1
PCB, PCM and PCH Overview .................................................................................................... 1
Installation ................................................................................................................................... 1
Technical Support ....................................................................................................................... 2
Directories ................................................................................................................................... 2
File Formats ................................................................................................................................. 3
Invoking the Command Line Compiler ...................................................................................... 5
PCW Overview ............................................................................................................................. 6
Program Syntax ............................................................................................................................ 17
Overall Structure ....................................................................................................................... 17
Comment .................................................................................................................................... 17
Trigraph Sequences .................................................................................................................. 19
Multiple Project Files ................................................................................................................ 19
Multiple Compilation Units ....................................................................................................... 20
Example ..................................................................................................................................... 22
Statements .................................................................................................................................... 23
Statements ................................................................................................................................. 23
if .................................................................................................................................................. 24
while ........................................................................................................................................... 25
do ................................................................................................................................................ 25
do-while...................................................................................................................................... 25
for ............................................................................................................................................... 26
switch ......................................................................................................................................... 26
return .......................................................................................................................................... 27
goto ............................................................................................................................................ 27
label ............................................................................................................................................ 27
break........................................................................................................................................... 28
continue ..................................................................................................................................... 28
expr............................................................................................................................................. 28
; ................................................................................................................................................... 29
stmt............................................................................................................................................. 29
Expressions .................................................................................................................................. 31
Expressions ............................................................................................................................... 31
Operators ................................................................................................................................... 31
operator precedence ................................................................................................................. 33
Reference Parameters .............................................................................................................. 34
Variable Argument Lists ........................................................................................................... 34
Default Parameters.................................................................................................................... 35
Overloaded Functions .............................................................................................................. 36
Data Definitions ............................................................................................................................ 37
Basic and Special types ........................................................................................................... 37
Declarations ............................................................................................................................... 41
Non-RAM Data Definitions........................................................................................................ 41
Using Program Memory for Data ............................................................................................. 43
Function Definition.................................................................................................................... 45
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C Compiler Reference Manual August 2009
Functional Overviews ................................................................................................................... 47
I2C............................................................................................................................................... 47
ADC ............................................................................................................................................ 48
Analog Comparator ................................................................................................................... 49
CAN Bus ..................................................................................................................................... 50
CCP1........................................................................................................................................... 52
CCP2, CCP3, CCP4, CCP5, CCP6............................................................................................. 53
Configuration Memory .............................................................................................................. 53
DAC ............................................................................................................................................ 54
Data Eeprom .............................................................................................................................. 55
External Memory ....................................................................................................................... 56
General Purpose I/O .................................................................................................................. 57
Internal LCD ............................................................................................................................... 58
Internal Oscillator ...................................................................................................................... 59
Interrupts ................................................................................................................................... 60
Linker ......................................................................................................................................... 61
Low Voltage Detect ................................................................................................................... 65
Power PWM ................................................................................................................................ 66
Program Eeprom ....................................................................................................................... 67
PSP ............................................................................................................................................. 69
PMP ............................................................................................................................................ 70
RS232 I/O ................................................................................................................................... 71
RTOS .......................................................................................................................................... 73
SPI .............................................................................................................................................. 75
Timer0 ........................................................................................................................................ 76
Timer1 ........................................................................................................................................ 77
Timer2 ........................................................................................................................................ 78
Timer3 ........................................................................................................................................ 79
Timer4 ........................................................................................................................................ 79
Timer5 ........................................................................................................................................ 79
USB............................................................................................................................................. 80
Voltage Reference ..................................................................................................................... 83
WDT or Watch Dog Timer ......................................................................................................... 84
Pre-Processor Directives ............................................................................................................. 85
PRE-PROCESSOR ..................................................................................................................... 85
#ASM #ENDASM .................................................................................................................... 87
#BIT ......................................................................................................................................... 90
#BUILD.................................................................................................................................... 91
#BYTE ..................................................................................................................................... 92
#CASE ..................................................................................................................................... 93
_DATE_ ................................................................................................................................... 93
#DEFINE ................................................................................................................................. 94
#DEVICE ................................................................................................................................. 95
_DEVICE_ ............................................................................................................................... 97
#ERROR .................................................................................................................................. 97
#EXPORT (options)................................................................................................................ 98
__FILE__ ................................................................................................................................. 99
__FILENAME__ ...................................................................................................................... 99
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Table Of Contents
#FILL_ROM ........................................................................................................................... 100
#FUSES ................................................................................................................................. 100
#HEXCOMMENT ................................................................................................................... 101
#ID ......................................................................................................................................... 101
#IF exp #ELSE #ELIF #ENDIF ............................................................................................ 102
#IFDEF #IFNDEF #ELSE #ELIF .......................................................................................... 103
#IGNORE_WARNINGS ......................................................................................................... 104
#IMPORT (options) .............................................................................................................. 104
#INCLUDE ............................................................................................................................. 106
#INLINE ................................................................................................................................. 106
#INT_xxxx ............................................................................................................................. 107
#INT_DEFAULT .................................................................................................................... 110
#INT_GLOBAL ...................................................................................................................... 111
__LINE__ .............................................................................................................................. 111
#LIST ..................................................................................................................................... 112
#LINE .................................................................................................................................... 112
#LOCATE .............................................................................................................................. 113
#MODULE ............................................................................................................................. 113
#NOLIST ............................................................................................................................... 114
#OPT ..................................................................................................................................... 114
#ORG .................................................................................................................................... 115
#OCS ..................................................................................................................................... 116
__PCB__ ............................................................................................................................... 117
__ PCM __ ............................................................................................................................. 117
__ PCH __ ............................................................................................................................. 118
#PIN_SELECT ...................................................................................................................... 118
#PRAGMA ............................................................................................................................. 119
#PRIORITY ............................................................................................................................ 119
#RESERVE ........................................................................................................................... 120
#ROM .................................................................................................................................... 120
#SEPARATE ......................................................................................................................... 121
#SERIALIZE .......................................................................................................................... 122
#TASK ................................................................................................................................... 123
__ TIME __ ............................................................................................................................ 124
#TYPE ................................................................................................................................... 124
#UNDEF ................................................................................................................................ 126
#USE DELAY ........................................................................................................................ 126
#USE DYNAMIC_MEMORY ................................................................................................. 127
#USE FAST_IO ..................................................................................................................... 128
#USE FIXED_IO .................................................................................................................... 128
#USE I2C ............................................................................................................................... 129
#USE RS232 ........................................................................................................................ 130
#USE RTOS ......................................................................................................................... 133
#USE SPI .............................................................................................................................. 134
#USE STANDARD_IO .......................................................................................................... 136
#USE TOUCHPAD ................................................................................................................ 136
#WARNING ........................................................................................................................... 137
#WORD ................................................................................................................................. 138
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C Compiler Reference Manual August 2009
#ZERO_RAM ........................................................................................................................ 138
Built-in-Functions ....................................................................................................................... 139
BUILT-IN-FUNCTIONS ............................................................................................................. 139
abs( ) ..................................................................................................................................... 143
adc_done( ) .......................................................................................................................... 143
assert( ) ................................................................................................................................. 144
atoe( ) .................................................................................................................................... 145
atof( )..................................................................................................................................... 145
atoi( ) atol( ) atoi32( ) ........................................................................................................... 146
bit_clear( ) ............................................................................................................................ 147
bit_set( ) ................................................................................................................................ 147
bit_test( ) .............................................................................................................................. 148
brownout_enable( ).............................................................................................................. 148
bsearch( ) ............................................................................................................................. 149
calloc( ) ................................................................................................................................. 150
ceil( ) ..................................................................................................................................... 150
clear_interrupt( ) .................................................................................................................. 151
dac_write( ) ........................................................................................................................... 151
delay_cycles( ) ..................................................................................................................... 152
delay_ms( ) ........................................................................................................................... 152
delay_us( ) ............................................................................................................................ 153
diable_interrupts( ) .............................................................................................................. 154
div( ) ldiv( ) ........................................................................................................................... 155
enable_interrupts( ) ............................................................................................................. 156
erase_eeprom ...................................................................................................................... 156
erase_program_eeprom( ) .................................................................................................. 157
exp( ) ..................................................................................................................................... 157
ext_int_edge( ) ..................................................................................................................... 158
fabs( ) .................................................................................................................................... 159
floor( ) ................................................................................................................................... 159
fmod( ) .................................................................................................................................. 160
free( )..................................................................................................................................... 160
frexp( ) .................................................................................................................................. 161
get_timerx( ) ......................................................................................................................... 161
get_tris_x( ) .......................................................................................................................... 162
getc( ) getch( ) getchar( ) fgetc( ) ........................................................................................ 163
getenv( ) ................................................................................................................................ 164
gets( ) fgets( ) ....................................................................................................................... 166
goto_address( ) .................................................................................................................... 167
i2c_isr_state( ) ..................................................................................................................... 167
i2c_poll( ) .............................................................................................................................. 168
I2C_read( ) ............................................................................................................................ 169
i2c_slaveaddr( ).................................................................................................................... 170
i2c_start( ) ............................................................................................................................ 170
i2c_stop( ) ............................................................................................................................. 171
i2c_write( ) ............................................................................................................................ 172
i2c_speed( ) .......................................................................................................................... 173
input( ) .................................................................................................................................. 173
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Table Of Contents
input_state( ) ........................................................................................................................ 174
input_x( ) .............................................................................................................................. 175
interrupt_active( ) ................................................................................................................ 175
isalnum(char) isalpha(char) isdigit(char) islower(char) isspace(char) isupper(char)
isxdigit(char) iscntrl(x) isgraph(x) isprint(x) ispunct(x) ................................................... 176
isamong( ) ............................................................................................................................ 177
itoa( ) ..................................................................................................................................... 177
jump_to_isr .......................................................................................................................... 178
kbhit( )................................................................................................................................... 179
label_address( ) ................................................................................................................... 180
labs( ) .................................................................................................................................... 180
lcd_load( ) ............................................................................................................................. 181
lcd_symbol( ) ....................................................................................................................... 181
ldexp( ) .................................................................................................................................. 182
log( ) ...................................................................................................................................... 183
log10( ) .................................................................................................................................. 184
longjmp( ) ............................................................................................................................. 184
make8( ) ................................................................................................................................ 185
make16( ) .............................................................................................................................. 185
make32( ) .............................................................................................................................. 186
malloc( ) ................................................................................................................................ 187
memcpy( ) memmove( ) ....................................................................................................... 187
memset( ) .............................................................................................................................. 188
modf( ) .................................................................................................................................. 189
_mul( ) ................................................................................................................................... 189
nargs( ) ................................................................................................................................. 190
offsetof( ) offsetofbit( ) ........................................................................................................ 191
output_x( ) ............................................................................................................................ 192
output_bit( ) .......................................................................................................................... 193
output_drive( )...................................................................................................................... 194
output_float( )....................................................................................................................... 194
output_high( )....................................................................................................................... 195
output_low( ) ........................................................................................................................ 196
output_toggle( ) ................................................................................................................... 196
perror( ) ................................................................................................................................. 197
port_x_pullups ( )................................................................................................................. 197
pow( ) pwr( ) ......................................................................................................................... 198
printf( ) fprintf( ) ................................................................................................................... 199
psp_output_full( ) psp_input_full( ) psp_overflow( ) ........................................................ 201
putc( ) putchar( ) fputc( ) ..................................................................................................... 202
puts( ) fputs( )....................................................................................................................... 203
qsort( ) .................................................................................................................................. 204
rand( ) ................................................................................................................................... 205
read_adc( ) ........................................................................................................................... 205
read_bank( ) ......................................................................................................................... 206
read_calibration( )................................................................................................................ 207
read_configuration_memory( ) ........................................................................................... 208
read_eeprom( ) ..................................................................................................................... 208
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C Compiler Reference Manual August 2009
read_program_eeprom( ) .................................................................................................... 209
read_program_memory( ) read_external_memory( ) ........................................................ 209
realloc( )................................................................................................................................ 210
reset_cpu( ) .......................................................................................................................... 211
restart_cause( ) .................................................................................................................... 211
restart_wdt( ) ........................................................................................................................ 212
rotate_left( ) .......................................................................................................................... 213
rotate_right( ) ....................................................................................................................... 213
rtos_await( ) ......................................................................................................................... 214
rtos_disable( ) ...................................................................................................................... 214
rtos_enable( ) ....................................................................................................................... 215
rtos_msg_poll( ) ................................................................................................................... 215
rtos_msg_read( ).................................................................................................................. 216
rtos_msg_send( ) ................................................................................................................. 216
rtos_overrun( ) ..................................................................................................................... 217
rtos_run( ) ............................................................................................................................. 217
rtos_signal( ) ........................................................................................................................ 218
rtos_stats( ) .......................................................................................................................... 218
rtos_terminate( ) .................................................................................................................. 219
rtos_wait( ) ........................................................................................................................... 219
rtos_yield( ) .......................................................................................................................... 220
set_adc_channel( ) .............................................................................................................. 220
set_adc_channel( ) .............................................................................................................. 221
set_power_pwmx_duty( ) .................................................................................................... 221
set_power_pwm_override( ) ............................................................................................... 222
set_pwm1_duty( ) set_pwm2_duty( ) set_pwm3_duty( ) set_pwm4_duty( )
set_pwm5_duty( ) ................................................................................................................ 223
set_rtcc( ) set_timer0( ) set_timer1( ) set_timer2( ) set_timer3( ) set_timer4( )
set_timer5( ) ......................................................................................................................... 224
set_timerx( ) ......................................................................................................................... 225
set_tris_x( ) .......................................................................................................................... 225
set_uart_speed( ) ................................................................................................................. 226
setjmp( ) ................................................................................................................................ 227
setup_adc(mode) ................................................................................................................. 227
setup_adc_ports( )............................................................................................................... 228
setup_ccp1( ) setup_ccp2( ) setup_ccp3( ) setup_ccp4( ) setup_ccp5( ) setup_ccp6( ) 229
setup_comparator( ) ............................................................................................................ 231
setup_counters( )................................................................................................................. 231
setup_dac( ) ......................................................................................................................... 232
setup_external_memory( ) .................................................................................................. 233
setup_lcd( ) .......................................................................................................................... 233
setup_low_volt_detect( ) ..................................................................................................... 234
setup_oscillator( ) ................................................................................................................ 235
setup_opamp1( ) setup_opamp2( ) .................................................................................... 235
setup_power_pwm( ) ........................................................................................................... 236
setup_power_pwm_pins( ).................................................................................................. 237
setup_pmp(option,address_mask) .................................................................................... 238
setup_qei( ) .......................................................................................................................... 239
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Table Of Contents
setup_spi( ) setup_spi2( ) ................................................................................................... 240
setup_psp(option,address_mask)...................................................................................... 240
setup_timer_0( ) ................................................................................................................... 241
setup_timer_1( ) ................................................................................................................... 242
setup_timer_2( ) ................................................................................................................... 243
setup_timer_3( ) ................................................................................................................... 244
setup_timer_4( ) ................................................................................................................... 245
setup_timer_5( ) ................................................................................................................... 246
setup_uart( ) ......................................................................................................................... 247
setup_vref( ) ......................................................................................................................... 248
setup_wdt( ) ......................................................................................................................... 249
shift_left( ) ............................................................................................................................ 250
shift_right( ) .......................................................................................................................... 251
sin( ) cos( ) tan( ) asin( ) acos() atan() sinh() cosh() tanh() atan2() .................................. 252
sleep( ) .................................................................................................................................. 253
sleep_ulpwu( ) ...................................................................................................................... 254
spi_data_is_in( ) spi_data_is_in2( ).................................................................................... 254
spi_read( ) spi_read2( ) ....................................................................................................... 255
spi_write( ) spi_write2( ) ...................................................................................................... 255
spi_xfer( ) ............................................................................................................................. 256
sprintf( ) ................................................................................................................................ 257
sqrt( ) .................................................................................................................................... 257
srand( ) ................................................................................................................................. 258
STANDARD STRING FUNCTIONS( ) memchr( ) memcmp( ) strcat( ) strchr( ) strcmp( )
strcoll( ) strcspn( ) ............................................................................................................... 259
strerror( ) stricmp( ) strlen( ) strlwr( ) strncat( ) strncmp( ) strncpy( ) strpbrk( ) strrchr( )
strspn( ) strstr( ) strxfrm( ) .................................................................................................. 259
strcpy( ) strcopy( ) ............................................................................................................... 260
strtod( ) ................................................................................................................................. 261
strtok( ) ................................................................................................................................. 262
strtol( ) .................................................................................................................................. 263
strtoul( ) ................................................................................................................................ 264
swap( ) .................................................................................................................................. 264
tolower( ) toupper( ) ............................................................................................................. 265
touchpad_getc( ) .................................................................................................................. 266
touchpad_hit( ) ..................................................................................................................... 267
touchpad_state( ) ................................................................................................................. 268
va_arg( ) ................................................................................................................................ 269
va_end .................................................................................................................................. 269
va_start ................................................................................................................................. 271
write_bank( ) ........................................................................................................................ 272
write_configuration_memory( ) .......................................................................................... 273
write_eeprom( ) .................................................................................................................... 273
write_external_memory( ) ................................................................................................... 274
write_program_eeprom( ) ................................................................................................... 275
write_program_memory( ) .................................................................................................. 276
Standard C Include Files ............................................................................................................ 277
errno.h ...................................................................................................................................... 277
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C Compiler Reference Manual August 2009
float.h ....................................................................................................................................... 277
limits.h...................................................................................................................................... 278
locale.h ..................................................................................................................................... 279
setjmp.h ................................................................................................................................... 279
stddef.h .................................................................................................................................... 279
stdio.h ...................................................................................................................................... 279
stdlib.h ..................................................................................................................................... 280
Error Messages ........................................................................................................................... 281
Compiler Error Messages ....................................................................................................... 281
Compiler Warning Messages ..................................................................................................... 293
Compiler Warning Messages ................................................................................................. 293
COMMON QUESTIONS AND ANSWERS ................................................................................... 297
How are type conversions handled? ..................................................................................... 297
How can a constant data table be placed in ROM? .............................................................. 299
How can I use two or more RS-232 ports on one PIC®? ..................................................... 300
How can the RB interrupt be used to detect a button press? ............................................. 301
How do I do a printf to a string? ............................................................................................ 301
How do I directly read/write to internal registers? ............................................................... 302
How do I get getc() to timeout after a specified time? ......................................................... 303
How do I make a pointer to a function? ................................................................................ 303
How do I put a NOP at location 0 for the ICD? ...................................................................... 304
How do I write variables to EEPROM that are not a byte?................................................... 304
How does one map a variable to an I/O port? ....................................................................... 305
How does the compiler determine TRUE and FALSE on expressions? ............................. 306
How does the PIC® connect to a PC? ................................................................................... 307
How does the PIC® connect to an I2C device? .................................................................... 308
How much time do math operations take? ........................................................................... 309
Instead of 800, the compiler calls 0. Why? ........................................................................... 310
Instead of A0, the compiler is using register 20. Why? ...................................................... 310
What can be done about an OUT OF RAM error?................................................................. 311
What is an easy way for two or more PICs® to communicate? .......................................... 311
What is the format of floating point numbers? ..................................................................... 312
Why does the .LST file look out of order? ............................................................................ 313
Why does the compiler show less RAM than there really is? ............................................. 314
Why does the compiler use the obsolete TRIS? .................................................................. 315
Why is the RS-232 not working right? ................................................................................... 315
EXAMPLE PROGRAMS .............................................................................................................. 317
EXAMPLE PROGRAMS ........................................................................................................... 317
SOFTWARE LICENSE AGREEMENT ......................................................................................... 345
SOFTWARE LICENSE AGREEMENT ..................................................................................... 345
xii
OVERVIEW
PCB, PCM and PCH Overview
The PCB, PCM, and PCH are separate compilers. PCB is for 12-bit opcodes, PCM is for 14-bit
opcodes, and PCH is for 16-bit opcode PIC® microcontrollers. Due to many similarities, all three
compilers are covered in this reference manual. Features and limitations that apply to only specific
microcontrollers are indicated within. These compilers are specifically designed to meet the unique
needs of the PIC® microcontroller. This allows developers to quickly design applications software
in a more readable, high-level language.
When compared to a more traditional C compiler, PCB, PCM, and PCH have some limitations. As
an example of the limitations, function recursion is not allowed. This is due to the fact that the PIC®
has no stack to push variables onto, and also because of the way the compilers optimize the code.
The compilers can efficiently implement normal C constructs, input/output operations, and bit
twiddling operations. All normal C data types are supported along with pointers to constant arrays,
fixed point decimal, and arrays of bits.
Installation
PCB, PCM, PCH, and PCD Installation:
Insert the CD ROM and from Windows Start|Run type:
D:SETUP
PCW, PCWH, PCWHD, and PCDIDE Installation:
Insert the CD ROM, select each of the programs you wish to install and follow the on-screen
instructions.
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C Compiler Reference Manual August 2009
Technical Support
Compiler, software, and driver updates are available to download at:
http://www.ccsinfo.com/download
Compilers come with 30 or 60 days of download rights with the initial purchase. One year
maintenance plans may be purchased for access to updates as released.
The intent of new releases is to provide up-to-date support with greater ease of use and minimal, if
any, transition difficulty.
To ensure any problem that may occur is corrected quickly and diligently, it is recommended to
send an email to "x-text-underline: normal; support@ccsinfo.com or use the Technical Support
Wizard in PCW. Include the version of the compiler, an outline of the problem and attach any files
with the email request. CCS strives to answer technical support timely and thoroughly.
Technical Support is available by phone during business hours for urgent needs or if email
responses are not adequate. Please call 262-522-6500 x32.
Directories
The compiler will search the following directories for Include files.
•
Directories listed on the command line
•
Directories specified in the .PJT file
•
The same directory as the source file
By default, the compiler files are put in C:\Program Files\PICC and the example programs and all
Include files are in C:\Program Files\PICC\EXAMPLES.
The compiler itself is a DLL file. The DLL files are in a DLL directory by default in C:\Program
Files\PICC\DLL. Old compiler versions may be kept by renaming this directory.
Compiler Version 4 and above can tolerate two compilers of different versions in the same
directory. Install an older version (4.xx ) and rename the devices4.dat file to devices4X.dat where
X is B for PCB, M is for PCM, and H is for PCH. Install the newer compiler and do the same
rename of the devices4.dat file.
2
Overview
File Formats
The compiler can output 8-bet hex, 16-bit hex, and binary files. Three listing formats are available:
1) Standard format resembles the Microchip tools, and may be required by other Third-Party tools.
2) Simple format is generated by compiler and is easier to read.
3) Symbolic format uses names versus addresses for registers.
The debug files may be output as Microchip .COD file, Advanced Transdata .MAP file, expanded
.COD file for CCS debugging or MPLAB 7.xx .COF file. All file formats and extensions may be
selected via Options File Associations option in Windows IDE.
.C
This is the source file containing user C source code.
.H
These are standard or custom header files used to define pins, register, register bits,
functions and preprocessor directives.
.PJT
This is the project file which contains information related to the project.
.LST
This is the listing file which shows each C source line and the associated assembly
code generated for that line.
The elements in the .LST file may be selected in PCW under Options>Project
Options>File Formats
Match
-Includes the HEX opcode for each instruction
code
SFR
-Instead of an address a name is used. For example instead of 044
names
is will show CORCON
Symbols
-Shows variable names instead of addresses
Interpret
-Adds a pseudo code interpretation to the right of assembly
instruction to help understand the operation.
For example:
LSR W4,#8,W5
:
W5=W4>>8
.SYM
This is the symbol map which shows each register location and what program
variables are stored in each location.
.STA
The statistics file shows the RAM, ROM, and STACK usage. It provides information
on the source codes structural and textual complexities using Halstead and McCabe
metrics.
.TRE
The tree file shows the call tree. It details each function and what functions it calls
along with the ROM and RAM usage for each function.
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C Compiler Reference Manual August 2009
.HEX
The compiler generates standard HEX files that are compatible with all programmers.
.COF
This is a binary containing machine code and debugging information.
.COD
This is a binary file containing debug information.
.RTF
The output of the Documentation Generator is exported in a Rich Text File format
which can be viewed using the RTF editor or wordpad.
.RVF
The Rich View Format is used by the RTF Editor within the IDE to view the Rich Text
File.
.DGR
The .DGR file is the output of the flowchart maker.
.ESYM
This file is generated for the IDE users. The file contains Identifiers and Comment
information. This data can be used for automatic documentation generation and for
the IDE helpers.
.OSYM
This file is generated when the compiler is set to export a relocatable object file. This
file is a .sym file for just the one unit.
4
Overview
Invoking the Command Line Compiler
The command line compiler is invoked with the following command:
CCSC
[options]
[cfilename]
Valid options:
+FB Select PCB (12 bit)
+FM Select PCM (14 bit)
+FH Select PCH (PIC18XXX)
+Yx Optimization level x (0-9)
+FS Select SXC (SX)
+ES Standard error file
+T Create call tree (.TRE)
+A Create stats file (.STA)
+EW Show warning messages
+EA Show all error messages and all warnings
-D
+DS
+DM
+DC
+EO
-T
-A
-EW
-E
+DF
Do not create debug file
Standard .COD format debug file
.MAP format debug file
Expanded .COD format debug file
Old error file format
Do not generate a tree file
Do not create stats file (.STA)
Suppress warnings (use with +EA)
Only show first error
Enables the output of a OFF debug file.
The xxx in the following are optional. If included it sets the file extension:
+LNxxx
+O8xxx
Normal list file
8-bit Intel HEX output file
+LSxxx
+OWxxx
MPASM format list file
16-bit Intel HEX output file
+LOxxx
+OBxxx
Old MPASM list file
Binary output file
+LYxxx
-O
Symbolic list file
Do not create object file
-L
Do not create list file
+P
Keep compile status window up after compile
+Pxx
Keep status window up for xx seconds after compile
+PN
Keep status window up only if there are no errors
+PE
Keep status window up only if there are errors
+Z
Keep scratch files on disk after compile
+DF
COFF Debug file
I+="..."
Same as I="..." Except the path list is appended to the current list
I="..."
Set include directory search path, for example:
I="c:\picc\examples;c:\picc\myincludes"
If no I= appears on the command line the .PJT file will be used to supply the include file paths.
-P
+M
-M
+J
-J
+ICD
#xxx="yyy"
Close compile window after compile is complete
Generate a symbol file (.SYM)
Do not create symbol file
Create a project file (.PJT)
Do not create PJT file
Compile for use with an ICD
Set a global #define for id xxx with a value of yyy, example:
#debug="true"
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C Compiler Reference Manual August 2009
+Gxxx="yyy"
+?
-?
+STDOUT
+SETUP
+V
+Q
Same as #xxx="yyy"
Brings up a help file
Same as +?
Outputs errors to STDOUT (for use with third party editors)
Install CCSC into MPLAB (no compile is done)
Show compiler version (no compile is done)
Show all valid devices in database (no compile is done)
A / character may be used in place of a + character. The default options are as follows:
+FM +ES +J +DC +Y9 -T -A +M +LNlst +O8hex -P -Z
If @filename appears on the CCSC command line, command line options will be read from the
specified file. Parameters may appear on multiple lines in the file.
If the file CCSC.INI exists in the same directory as CCSC.EXE, then command line parameters are
read from that file before they are processed on the command line.
Examples:
CCSC +FM C:\PICSTUFF\TEST.C
CCSC +FM +P +T TEST.C
PCW Overview
Beginning in version 4.XXX of PCW, the menus and toolbars are set-up in specially organized
Ribbons. Each Ribbon relates to a specific type of activity an is only shown when selected. CCS has
included a "User Toolbar" Ribbon that allows the user to customize the Ribbon for individual needs.
File Menu
Click on this icon for the following items:
New
Creates a new File
Open
Opens a file to the editor. Includes options for Source, Project, Output, RTF, Flow
Chart, Hex or Text. Ctrl+O is the shortcut.
Close
Closes the file currently open for editing. Note, that while a file is open in PCW for
editing, no other program may access the file. Shift+F11 is the shortcut.
Close All
Closes all files open in the PCW.
Save
Saves the file currently selected for editing. Crtl+S is the shortcut.
6
Overview
Save As
Prompts for a file name to save the currently selected file.
Save All
All open files are saved.
Encrypt
Creates an encrypted include file. The standard compiler #include directive will
accept files with this extension and decrypt them when read. This allows include files
to be distributed without releasing the source code.
Print
Prints the currently selected file.
Recent
Files
Exit
The right-side of the menu has a Recent Files list for commonly used files.
The bottom of the menu has an icon to terminate PCW.
Project Menu Ribbon
Project
Open an existing project (.PJT) file as specified and the main source file is loaded.
PIC Wizard
This command is a fast way to start a new project. It will bring up a screen with fillin-the-blanks to create a new project. When items such as RS232 I/O, i2C, timers,
interrupts, A/D options, drivers and pin name are specified by the user, the Wizard
will select required pins and pins that may have combined use. After all selections
are made, the initial .c and .h files are created with #defines, #includes and
initialization commands required for the project.
Create
Create a new project with the ability to add/remove source files, include files, global
defines and specify output files.
Open All
Files
Close
Project
Find Text
in Project
Open all files in a project so that all include files become known for compilation.
Close all files associated with project.
Ability to search all files for specific text string.
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C Compiler Reference Manual August 2009
Edit Menu Ribbon
Undo
Undoes the last deletion
Redo
Re-does the last undo
Cut
Moves the selected text from the file to the clipboard.
Copy
Copies the selected text to the clipboard.
Paste
Applies the clipboard contents to the cursor location.
Unindent
Selection
Selected area of code will not be indented.
Indent
Selection
Selected area of code will be properly indented.
Select All
Highlighting of all text.
Copy
from File
Copies the contents of a file to the cursor location.
Past to
File
Macros
Applies the selected text to a file.
8
Macros for recording, saving and loading keystrokes and mouse-strokes.
Overview
Search Menu Ribbon
Find
Locate text in file.
Find Text in
Project
Searches all files in project for specific text string.
Find Next Word
at Cursor
Locates the next occurrence of the text selected in the file.
Goto Line
Cursor will move to the user specified line number.
Toggle
Bookmark
Goto Bookmark
Set/Remove bookmark (0-9) at the cursor location.
Move cursor to the specified bookmark (0-9).
Options Menu Ribbon
Project Options
Add/remove files, include files, global defines and output files.
Editor Properties
Allows user to define the set-up of editor properties for Windows options.
Tools
Window display of User Defined Tools and options to add and apply.
Software
Updates
Properties
Printer Setup
Ability for user to select which software to update, frequency to remind
Properties user and where to archive files.
Toolbar Setup
Customize the toolbar properties to add/remove icons and keyboard
commands.
File Associations
Customize the settings for files according to software being used.
Set the printer port and paper and other properties for printing.
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C Compiler Reference Manual August 2009
Compile Menu Ribbon
Compile
Compiles the current project in status bar using the current compiler.
Build
Compiles one or more files within a project.
Compiler
Pull-down menu to choose the compiler needed.
Lookup
Part
Program
Chip
Choose a device and the compiler needed will automatically be selected.
Debug
Allows for input of .hex and will output .asm for debugging.
C/ASM
List
Opens listing file in read-only mode. Will show each C source line code and the
associated assembly code generated.
Symbol
Map
Opens the symbol file in read-only mode. Symbol map shows each register location
and what program variable are saved in each location.
Call Tree
Opens the tree file in read-only mode. The call tree shows each function and what
functions it calls along with the ROM and RAM usage for each.
Statistics
Opens the statistics file in read-only mode. The statistics file shows each function,
the ROM and RAM usage by file, segment and name.
Debug
File
Opens the debug file in read-only mode. The listing file shows each C source line
code and the associated assembly code generated.
10
Lists the options of CCS ICD or Mach X programmers and will connect to SIOW
program.
Overview
View Menu Ribbon
Valid
Interrupts
This displays a list of valid interrupts used with the #INT_keyword for the chip used
in the current project. The interrupts for other chips can be viewed using the drop
down menu.
Valid
Fuses
This displays a list of valid FUSE used with the #FUSES directive associated with
the chip used in the current project. The fuses for other chips can be viewed using
the drop down menu.
Data
Sheets
This tool is used to view the Manufacturer data sheets for all the Microchip parts
supported by the compiler.
Part
Errata
This allows user to view the errata database to see what errata is associated with a
part and if the compiler has compensated for the problem.
Special
Registers
This displays the special function registers associated with the part.
New Edit
Window
This will open a new edit window which can be tiled to view files side by side.
Dock
Editor
Window
Selecting this checkbox will dock the editor window into the IDE.
Project
Files
When this checkbox is selected, the Project files slide out tab is displayed. This will
allow quicker access to all the project source files and output files.
Project
List
Selecting this checkbox displays the Project slide out tab. The Project slide out tab
displays all the recent project files.
Output
Selecting this checkbox will enable the display of warning and error messages
generated by the compiler.
Identifier
List
Selecting this checkbox displays the Identifier slide out tab. It allows quick access to
project identifiers like functions, types, variables and defines.
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C Compiler Reference Manual August 2009
Tools Menu Ribbon
Device Editor
This tool is used to edit the device database used by the compiler to control
compilations. The user can edit the chip memory, interrupts, fuses and other
peripheral settings for all the supported devices.
Device
Selector
This tool uses the device database to allow for parametric selection of devices.
The tool displays all eligible devices based on the selection criteria.
File Compare
This utility is used to compare two files. Source or text files can be compared line
by line and list files can be compared by ignoring the RAM/ROM addresses to
make the comparisons more meaningful.
Numeric
Converter
This utility can be used to convert data between different formats. The user can
simultaneously view data in various formats like binary, hex, IEEE, signed and
unsigned.
Serial Port
Monitor
This tool is an easy way of connecting a PIC to a serial port. Data can be viewed
in ASCII or hex format. An entire hex file can be transmitted to the PIC which is
useful for bootloading application.
Disassembler
This tool will take an input hex file and output an ASM.
Convert Data
to C
This utility will input data from a text file and generate code is form of a #ROM or
CONST statement.
Extract
Calibration
This tool will input a hex file and extract the calibration data to a C include file.
This feature is useful for saving calibration data stored at top of program memory
from certain PIC chips.
MACH X
This will call the Mach-X.exe program and will download the hex file for the
current project onto the chip.
ICD
This will call the ICD.exe program and will download the hex file for the current
project onto the chip.
12
Overview
Debug Menu Ribbon
Enable
Debugger
Enables the debugger. Opens the debugger window, downloads the code and onchip debugger and resets the target into the debugger.
Reset
This will reset the target into the debugger.
Single
Step
Executes one source code line at a time. A single line of C source code or ASM
code is executed depending on whether the source code or the list file tab in the
editor is active.
Step Over
This steps over the target code. It is useful for stepping over function calls.
Run to
Cursor
Runs the target code to the cursor. Place the cursor at the desired location in the
code and click on this button to execute the code till that address.
Snapshot
This allows users to record various debugging information. Debug information like
watches, ram values, data eeprom values, rom values , peripheral status can be
conveniently logged. This log can be saved, printed, overwritten or appended.
Run
Script
This tool allows the IDE's integrated debugger to execute a C-style script. The
functions and variable of the program can be accesses and the debugger creates a
report of the results.
Debug
Windows
This drop down menu allows viewing of a particular debug tab. Click on the tab
name in the drop down list which you want to view and it will bring up that tab in the
debugger window.
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C Compiler Reference Manual August 2009
Document Menu Ribbon
Format
Source
This utility formats the source file for indenting, color syntax highlighting, and other
formatting options.
Generate
Document
This will call the document generator program which uses a user generated
template in .RTF format to merge with comment from the source code to produce
an output file in .RTF format as source code documentation.
RTF Editor
Open the RTF editor program which is a fully featured RTF editor to make
integration of documentation into your project easier.
Flow Chart
Opens a flow chart program for quick and easy charting. This tool can be used to
generate simple graphics including schematics.
Quotes
Performs a spell check on all the words within quotes.
Comments
Performs a spell check on all the comments in your source code.
Print all
Files
Print all the files of the current project.
14
Overview
Help Menu
Click on this icon for the following items:
Contents
Help File table of contents
Index
Help File index
Keyword at
Cursor
Index search in Help File for the keyword at the cursor location. Press F1 to use
this feature.
Debugger
Help
Help File specific to debugger functionality.
Editor
Lists the Editor Keys available for use in PCW. Shft+F12 will also call this
function help file page for quick review.
Data Types
Specific Help File page for basic data types.
Operators
Specific Help File page for table of operators that may be used in PCW.
Statements
Specific Help File page for table of commonly used statements.
Preprocessor
Commands
Specific Help File page for listing of commonly used preprocessor commands.
Built-in
Functions
Specific Help File page for listing of commonly used built-in functions provided by
the compiler.
Technical
Support
Technical Support wizard to directly contact Technical Support via email and the
ability to attach files.
Check for
Software
Updates
Automatically invokes Download Manager to view local and current versions of
software.
Internet
Direct links to specific CCS website pages for additional information.
About
Shows the version of compiler(s) and IDE installed.
15
PROGRAM SYNTAX
Overall Structure
A program is made up of the following four elements in a file:
Comment
Pre-Processor Directive
Data Definition
Function Definition
Every C program must contain a main function which is the starting point of the program execution.
The program can be split into multiple functions according to the their purpose and the functions
could be called from main or the subfunctions. In a large project functions can also be placed in
different C files or header files that can be included in the main C file to group the related functions
by their category. CCS C also requires to include the appropriate device file using #include
directive to include the device specific functionality. There are also some preprocessor directives
like #fuses to specify the fuses for the chip and #use delay to specify the clock speed. The
functions contain the data declarations,definitions,statements and expressions. The compiler also
provides a large number of standard C libraries as well as other device drivers that can be included
and used in the programs. CCS also provides a large number of built-in functions to access the
various peripherals included in the PIC microcontroller.
Comment
Comments – Standard Comments
A comment may appear anywhere within a file except within a quoted string. Characters between /*
and */ are ignored. Characters after a // up to the end of the line are ignored.
Comments for Documentation GeneratorThe compiler recognizes comments in the source code based on certain markups. The compiler
recognizes these special types of comments that can be later exported for use in the
documentation generator. The documentation generator utility uses a user selectable template to
export these comments and create a formatted output document in Rich Text File Format. This
utility is only available in the IDE version of the compiler. The source code markups are as follows.
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C Compiler Reference Manual August 2009
Global Comments – These are named comments that appear at the top of your source code. The
comment names are case sensitive and they must match the case used in the documentation template.
For example:
//*PURPOSE This program implements a Bootloader.
//*AUTHOR John Doe
A '//' followed by an * will tell the compiler that the keyword which follows it will be the named comment. The
actual comment that follows it will be exported as a paragraph to the documentation generator.
Multiple line comments can be specified by adding a : after the *, so the compiler will not concatenate the
comments that follow. For example:
/**:CHANGES
05/16/06 Added PWM loop
05/27.06 Fixed Flashing problem
*/
Variable Comments – A variable comment is a comment that appears immediately after a variable
declaration. For example:
int seconds; // Number of seconds since last entry
long day, // Current day of the month
int month, /* Current Month */
long year;
// Year
Function Comments – A function comment is a comment that appears just before a function
declaration. For example:
// The following function initializes outputs
void function_foo()
{
init_outputs();
}
Function Named Comments – The named comments can be used for functions in a similar manner
to the Global Comments. These comments appear before the function, and the names are
exported as-is to the documentation generator.
For example:
//*PURPOSE This function displays data in BCD format
void display_BCD( byte n)
{
display_routine();
}
18
Program Syntax
Trigraph Sequences
The compiler accepts three character sequences instead of some special characters not available
on all keyboards as follows:
Sequence Same as
??=
#
??(
[
??/
\
??)
]
??'
^
??<
{
??!
|
??>
}
??~
Multiple Project Files
When there are multiple files in a project they can all be included using the #include in the main file
or the subfiles to use the automatic linker included in the compiler. All the header files, standard
libraries and driver files can be included using this method to automatically link them.
For example: if you have main.c, x.c, x.h, y.c,y.h and z.c and z.h files in your project, you can say in:
main.c
#include
x.c
y.c
#include
#include
z.c
#include
#include
#include
#include
In this example there are 8 files and one compilation unit. Main.c is the only file compiled.
Note that the #module directive can be used in any include file to limit the visibility of the symbol in that file.
To separately compile your files see the section "multiple compilation units".
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C Compiler Reference Manual August 2009
Multiple Compilation Units
Traditionally the CCS C compilers used only one compilation unit and multiple files were
implemented with #include files. When using multiple compilation units care must be given that
preprocessor commands that control the compilation are compatible across all units. It is
recommended directives such as #fuses, #use and the device header file all be put in an include
file included by all units. When a unit is compiled it will output a relocatable object file (.o) and
symbol file (.osym).
For a detailed example see MCV.zip in the examples directory.
The following is an overview of a multiple compilation unit example:
main.c
filter.c
report.c
project.h
filter.h
report.h
build.bat
build.bat
project.pjt
Primary file for the first compilation unit
Primary file for the second compilation unit
Primary file for the third compilation unit
Include file with project wide definitions, should be included by all units
External definitions for filter, should be included by all units that use the filter unit
External definitions for report, should be included by all units that use report
Batch file that compiles and links all units
Batch file that recompiles files needing compiling and links
Used by build.bat to list project units
main
filter
report
#include's:
project.h
filter.h
report.h
#include's:
project.h
report.h
#include's:
project.h
Definitions:
main() program
Public Definitions:
clear_data()
filter_data()
Public Definitions:
report_line_number
report_data_line()
report_error()
Uses:
clear_data()
filter_data()
report_data_line()
report_line_number
Uses:
report_error()
Each unit:
*.o (relocatable object)
*.err (error file)
*.osym (unit symbols)
project.hex (final load image)
project.lst (C and ASM listing)
project.sym (project symbols)
project.cof (debugger file)
20
Program Syntax
Notes
• By default, variables declared at the unit level (outside a function) are visible to all other
units. To make a variable private to the unit use the keyword static. Notice report.c defines
the varable report_line_number. If the definition were changed to look as the following
line, then there would be a link time error since main.c attempts to use the variable.
static long report_line_number;
• This same rule applies to functions. Use static to make a function local to the unit.
• Should two units have a function, or unit level variable with the same name, an error is
generated unless one of the following is true:
• The identifier is qualified with static.
• The argument list is different and two instances of the function can co-exist in
the project in accordance with the normal overload rules.
• The contents of the functions are absolutely identical. In this case the CCS
linker simply deletes the duplicate function.
• The standard C libraries (like stdlib.h) are supplied with source code in the .h file. Because
of the above rule, these files may be #include'd in multiple units without taking up extra ROM
and with no need to include these in the link command since they are not units.
• #define's are never exported to other units. If a #define needs to be shared between
units put them in an include file that is #include'd by both units. Project wide defines in
our example could go into prject.h
• It is best to have an include file like project.h that all units #include. This file should
define the chip, speed, fuses and any other compiler settings that should be the same
for all units in the project.
• In this example project a #USE RS232 is in the project.h file. This creates an RS232
library in each unit. The linker is able to determine the libraries are the same and the
duplicates removed in the final link.
• Each unit has it own error file (like filter.err). When the compilations are done in a batch
file it may be useful to terminate the batch run on the first error. The +CC command line
option will cause the compiler to return a windows error code if the compilation fails.
This can be tested in the batch file like this:
"c:\program files\picc\ccsc"+FM +CC +EXPORT report.c
if not errorlevel 1 goto abort
...
goto end
:abort
echo COMPILE ERROR
:end
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C Compiler Reference Manual August 2009
Example
Here is a sample program with explanation using CCS C to read adc samples over rs232:
///////////////////////////////////////////////////////
/// This program displays the min and max of 30,
///
/// comments that explains what the program does, ///
/// and A/D samples over the RS-232 interface.
///
///////////////////////////////////////////////////////
#if defined(__PCM__)
// preprocessor directive that
chooses the compiler
#include <16F877.h>
// preprocessor directive that
selects the chip PIC16F877
#fuses HS,NOWDT,NOPROTECT,NOLVP
// preprocessor directive that
defines fuses for the chip
#use delay(clock=20000000)
// preprocessor directive that
specifies the clock speed
#use rs232(baud=9600, xmit=PIN_C6, rcv=PIN_C7) // preprocessor directive that
includes the rs232 libraries
#elif defined(__PCH__)
// same as above but for the PCH
compiler and PIC18F452
#include <18F452.h>
#fuses HS,NOWDT,NOPROTECT,NOLVP
#use delay(clock=20000000)
#use rs232(baud=9600, xmit=PIN_C6, rcv=PIN_C7)
#endif
void main() {
// main function
int i, value, min, max;
// local variable declaration
printf("Sampling:");
// printf function included in
the RS232 library
setup_port_a( ALL_ANALOG );
// A/D setup functions- built-in
setup_adc( ADC_CLOCK_INTERNAL );
// A/D setup functions- built-in
set_adc_channel( 0 );
// A/D setup functions- built-in
do {
// do while statement
min=255;
// expression
max=0;
for(i=0; i<=30; ++i) {
// for statement
delay_ms(100);
// delay built-in function call
value = Read_ADC();
if(valuemax)
max=value;
}
printf("\n\rMin: %2X
} while (TRUE);
}
22
// A/D read functions- built-in
// if statement
// if statement
Max: %2X\n\r",min,max);
STATEMENTS
Statements
STATEMENT
if (expr) stmt; [else stmt;]
while (expr) stmt;
do stmt while (expr);
for (expr1;expr2;expr3) stmt;
switch (expr) {
case cexpr: stmt; //one or more case
[default:stmt]
... }
if (x==25)
x=1;
else
x=x+1;
while (get_rtcc()!=0)
putc(‘n’);
do {
putc(c=getc());
} while (c!=0);
for (i=1;i<=10;++i)
printf(“%u\r\n”,i);
return [expr];
switch (cmd) {
case 0: printf(“cmd 0”);
break;
case 1: priintf(“cmd 1”);
break;
default: printf(“bad cmd”);
break; }
return (5);
goto label;
goto loop;
label: stmt;
loop: I++;
break;
break;
continue;
continue;
expr;
i=1;
;
;
{[stmt]}
{a=1;
b=1;}
Zero or more
Note: Items in [ ] are optional
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C Compiler Reference Manual August 2009
if
if-else
The if-else statement is used to make decisions.
The syntax is :
if (expr)
stmt-1;
[else
stmt-2;]
The expression is evaluated; if it is true stmt-1 is done. If it is false then stmt-2 is done.
else-if
This is used to make multi-way decisions.
The syntax is
if (expr)
stmt;
[else if (expr)
stmt;]
...
[else
stmt;]
The expression's are evaluated in order; if any expression is true, the statement associated with it
is executed and it terminates the chain. If none of the conditions are satisfied the last else part is
executed.
Example:
if (x==25)
x=1;
else
x=x+1;
Also See: Statements
24
Statements
while
While is used as a loop/iteration statement.
The syntax is
while (expr)
statement
The expression is evaluated and the statement is executed until it becomes false in which case the
execution continues after the statement.
Example:
while (get_rtcc()!=0)
putc('n');
Also See: Statements
do
Statement: do stmt while (expr);
Example:
do {
putc(c=getc());
} while (c!=0);
Also See: Statements , While
do-while
It differs from While and For loop in that the termination condition is checked at the bottom of the
loop rather than at the top and so the body of the loop is always executed at least once.
The syntax is
do
statement
while (expr);
The statement is executed; the expr is evaluated. If true, the same is repeated and when it
becomes false the loop terminates.
Also See: Statements , While
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C Compiler Reference Manual August 2009
for
For is also used as a loop/iteration statement.
The syntax is
for (expr1;expr2;expr3)
statement
The expressions are loop control statements. expr1 is the initialization, expr2 is the termination
check and expr3 is re-initialization. Any of them can be omitted.
Example:
for (i=1;i<=10;++i)
printf("%u\r\n",i);
Also See: Statements
switch
Switch is also a special multi-way decision maker.
The syntax is
switch (expr) {
case const1: stmt sequence;
break;
...
[default:stmt]
}
This tests whether the expression matches one of the constant values and branches accordingly.
If none of the cases are satisfied the default case is executed. The break causes an immediate exit,
otherwise control falls through to the next case.
Example:
switch (cmd) {
case 0:printf("cmd 0");
break;
case 1:printf("cmd 1");
break;
default:printf("bad cmd");
break; }
Also See: Statements
26
Statements
return
Statement: return [expr];
A return statement allows an immediate exit from a switch or a loop or function and also returns a
value.
The syntax is
return(expr);
Example:
return (5);
Also See: Statements
goto
Statement: goto label;
The goto statement cause an unconditional branch to the label.
The syntax is
goto label;
A label has the same form as a variable name, and is followed by a colon. The goto's are used
sparingly, if at all.
Example:
goto loop;
Also See: Statements
label
Statement: label: stmt;
Example:
loop: i++;
Also See: Statements
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C Compiler Reference Manual August 2009
break
Statement: break;
The break statement is used to exit out of a control loop. It provides an early exit from while, for ,do
and switch.
The syntax is
break;
It causes the innermost enclosing loop(or switch) to be exited immediately.
Example:
break;
Also See: Statements
continue
Statement: continue;
The continue statement causes the next iteration of the enclosing loop(While, For, Do) to begin.
The syntax is
continue;
It causes the test part to be executed immediately in case of do and while and the control passes
the re-initialization step in case of for.
Example:
continue;
Also See: Statements
expr
Statement: expr;
Example:
i=1;
Also See: Statements
28
Statements
;
Statement: ;
Example:
;
Also See: Statements
stmt
Statement: {[stmt]}
Zero or more semi colon separated
Example:
{a=1;
b=1;}
Also See: Statements
29
EXPRESSIONS
Expressions
Constants:
123
0123
0x123
0b010010
'x'
'\010'
'\xA5’
'\c'
"abcdef"
Identifiers:
ABCDE
ID[X]
ID[X][X]
ID.ID
ID->ID
Up to 32 characters beginning with a non-numeric. Valid characters are
A-Z, 0-9 and _ (underscore).
Single Subscript
Multiple Subscripts
Structure or union reference
Structure or union reference
Operators
+
Addition Operator
+=
Addition assignment operator, x+=y, is the same as x=x+y
&=
Bitwise and assignment operator, x&=y, is the same as x=x&y
&
Address operator
&
Bitwise and operator
^=
Bitwise exclusive or assignment operator, x^=y, is the same as x=x^y
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C Compiler Reference Manual August 2009
^
Bitwise exclusive or operator
l=
Bitwise inclusive or assignment operator, xl=y, is the same as x=xly
l
Bitwise inclusive or operator
?:
Conditional Expression operator
--
Decrement
/=
Division assignment operator, x/=y, is the same as x=x/y
/
Division operator
==
Equality
>
Greater than operator
>=
Greater than or equal to operator
++
Increment
*
Indirection operator
!=
Inequality
<<=
Left shift assignment operator, x<<=y, is the same as x=x<>=
Right shift assignment, x>>=y, is the same as x=x>>y
>>
Right shift operator
->
Structure Pointer operation
-=
Subtraction assignment operator
-
Subtraction operator
sizeof
Determines size in bytes of operand
32
Expressions
operator precedence
IN DESCENDING PIN DESCENDING PRECEDENCE
(expr)
!expr
~expr
++expr
expr++
(type)expr
*expr
&value
sizeof(type)
expr*expr
expr/expr
expr%expr
expr+expr
expr<>expr
expr<=expr
expr>expr
expr==expr
expr&expr
expr^expr
expr | expr
expr&& expr
expr || expr
expr ? expr: expr
lvalue = expr
expr!=expr
lvalue+=expr
lvalue-=expr
lvalue*=expr
lvalue/=expr
lvalue%=expr
lvalue>>=expr
lvalue<<=expr
lvalue&=expr
lvalue^=expr
lvalue|=expr
expr, expr
- -expr
expr - -
expr>=expr
(Operators on the same line are equal in precedence)
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C Compiler Reference Manual August 2009
Reference Parameters
The compiler has limited support for reference parameters. This increases the readability of code
and the efficiency of some inline procedures. The following two procedures are the same. The one
with reference parameters will be implemented with greater efficiency when it is inline.
funct_a(int*x,int*y){
/*Traditional*/
if(*x!=5)
*y=*x+3;
}
funct_a(&a,&b);
funct_b(int&x,int&y){
/*Reference params*/
if(x!=5)
y=x+3;
}
funct_b(a,b);
Variable Argument Lists
The compiler supports a variable number of parameters. This works like the ANSI requirements
except that it does not require at least one fixed parameter as ANSI does. The function can be passed
any number of variables and any data types. The access functions are VA_START, VA_ARG, and
VA_END. To view the number of arguments passed, the NARGS function can be used.
/*
stdarg.h holds the macros and va_list data type needed for variable
number of parameters.
*/
#include
A function with variable number of parameters requires two things. First, it requires the ellipsis (...),
which must be the last parameter of the function. The ellipsis represents the variable argument list.
Second, it requires one more variable before the ellipsis (...). Usually you will use this variable as a
method for determining how many variables have been pushed onto the ellipsis.
Here is a function that calculates and returns the sum of all variables:
34
Expressions
int Sum(int count, ...)
{
//a pointer to the argument list
va_list al;
int x, sum=0;
//start the argument list
//count is the first variable before the ellipsis
va_start(al, count);
while(count--) {
//get an int from the list
x = var_arg(al, int);
sum += x;
}
//stop using the list
va_end(al);
return(sum);
}
Some examples of using this new function:
x=Sum(5, 10, 20, 30, 40, 50);
y=Sum(3, a, b, c);
Default Parameters
Default parameters allows a function to have default values if nothing is passed to it when called.
int mygetc(char *c, int n=100){
}
This function waits n milliseconds for a character over RS232. If a character is received, it saves it
to the pointer c and returns TRUE. If there was a timeout it returns FALSE.
//gets a char, waits 100ms for timeout
mygetc(&c);
//gets a char, waits 200ms for a timeout
mygetc(&c, 200);
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C Compiler Reference Manual August 2009
Overloaded Functions
Overloaded functions allow the user to have multiple functions with the same name, but they must
accept different parameters. The return types must remain the same.
Here is an example of function overloading: Two functions have the same name but differ in the
types of parameters. The compiler determines which data type is being passed as a parameter and
calls the proper function.
This function finds the square root of a long integer variable.
long FindSquareRoot(long n){
}
This function finds the square root of a float variable.
float FindSquareRoot(float n){
}
FindSquareRoot is now called. If variable is of long type, it will call the first FindSquareRoot()
example. If variable is of float type, it will call the second FindSquareRoot() example.
result=FindSquareRoot(variable);
36
DATA DEFINITIONS
Basic and Special types
This section describes what the basic data types and specifiers are and how variables can be
declared using those types. In C all the variables should be declared before they are used. They
can be defined inside a function (local) or outside all functions (global). This will affect the visibility
and life of the variables.
Basic Types
Range
Type-Specifier
Unsigned
Size
Signed
Digits
int1
1 bit number
0 to 1
N/A
1/2
int8
8 bit number
0 to 255
-128 to 127
2-3
int16
16 bit number
0 to 65535
-32768 to 32767
4-5
int32
32 bit number
0 to 4294967295
-2147483648 to 2147483647
9-10
float32
32 bit float
C Standard Type
short
char
int
long
long long
float
-1.5 x 1045 to 3.4 x 1038
7-8
Default Type
int1
unsigned int8
int8
int16
int32
float32
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C Compiler Reference Manual August 2009
Note: All types, except float, by default are unsigned; however, may be preceded by unsigned or
signed. Short and long may have the keyword INT following them with no effect. Also see #TYPE
to change the default size.
SHORT is a special type used to generate very efficient code for bit operations and I/O. Arrays of
bits (INT1) in RAM are now supported. Pointers to bits are not permitted. The device header files
contain defines for BYTE as an int8 and BOOLEAN as an int1.
Integers are stored in little endian format. The LSB is in the lowest address. Float formats are
described in common questions.
Type-Qualifier
static
Variable is globally active and initialized to 0. Only accessible from this
compilation unit.
auto
Variable exists only while the procedure is active. This is the default and AUTO
need not be used.
double
Is a reserved word but is not a supported data type.
extern
External variable used with multiple compilation units. No storage is allocated. Is
used to make otherwise out of scope data accessible. there must be a nonextern definition at the global level in some compilation unit.
register
Is allowed as a qualifier however, has no effect.
_fixed(n)
Creates a fixed point decimal number where n is how many decimal places to
implement.
unsigned
Data is always positive. This is the default data type if not specified.
signed
Data can be negative or positive.
volatile
Tells the compiler optimizer that this variable can be changed at any point during
execution.
const
Data is read-only. Depending on compiler configuration, this qualifier may just
make the data read-only -AND/OR- it may place the data into program memory to
save space.
void
Built-in basic type. Type void is used for declaring main programs and
subroutines.
38
Data Definitions
Special types
Enum enumeration type: creates a list of integer constants.
enum
[id]
{ [ id [ = cexpr]] }
One or more comma separated
The id after ENUM is created as a type large enough to the largest constant in the list. The ids in
the list are each created as a constant. By default the first id is set to zero and they increment by
one. If a =cexpr follows an id that id will have the value of the constant expression and the
following list will increment by one.
For example:
enum colors{red, green=2,blue};
blue will be 3
// red will be 0, green will be 2 and
Struct structuretype: creates a collection of one or more variables, possibly of different types,
grouped together as a single unit.
struct[*] [id] {
type-qualifier [*] id
[:bits];
One or more,
semi-colon
separated
Zero
or more
} [id]
For example:
struct data_record {
int
a [2];
int b : 2; /*2 bits */
int c : 3; /*3 bits*/
int d;
}data_var;
// data_record is a structure type
//data _var is a variable
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C Compiler Reference Manual August 2009
Union union type: holds objects of different types and sizes, with the compiler keeping track of
size and alignment requirements. They provide a way to manipulate different kinds of data in a
single area of storage.
union[*] [id] {
type-qualifier [*] id
[:bits];
One or more,
semi-colon
separated
Zero
or more
For example:
union u_tab {
int ival;
long lval;
float fval;
};
a float
} [id]
// u_tag is a union type that can hold
If typedef is used with any of the basic or special types it creates a new type name that can be
used in declarations. The identifier does not allocate space but rather may be used as a type
specifier in other data definitions.
typedef
[type-qualifier] [type-specifier] [declarator];
For example:
typedef
specify
typedef
specify
typedef
used to
int mybyte;
// mybyte can be used in declaration to
the int type
short mybit;
// mybyte can be used in declaration to
the int type
enum {red, green=2,blue}colors;
//colors can be
declare variables of
//this enum type
__ADDRESS__: A predefined symbol __ADDRESS__ may be used to indicate a type that must
hold a program memory address.
For example:
___ADDRESS__ testa = 0x1000
initialize to 0x1000
40
//will allocate 16 bits for testa and
Data Definitions
Declarations
A declaration specifies a type qualifier and a type specifier, and is followed by a list of one or more
variables of that type.
For e.g.:
int a,b,c,d;
mybit e,f;
mybyte g[3][2];
char *h;
colors j;
struct data_record data[10];
static int i;
extern long j;
Variables can also be declared along with the definitions of the special types.
For eg:
enum colors{red, green=2,blue}i,j,k;
i,j,k are variables of that type
// colors is the enum type and
Non-RAM Data Definitions
CCS C compiler also provides a custom qualifier addressmod which can be used to define a
memory region that can be RAM, program eeprom, data eeprom or external memory. Addressmod
replaces the older typemod (with a different syntax).
The usage is :
addressmod (name,read_function,write_function,start_address,end_address);
Where the read_function and write_function should be blank for RAM, or for other memory should
be the following prototype:
// read procedure for reading n bytes from the memory starting at location
addr
void read_function(int32 addr,int8 *ram, int nbytes){
}
//write procedure for writing n bytes to the memory starting at location addr
void write_function(int32 addr,int8 *ram, int nbytes){
}
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C Compiler Reference Manual August 2009
Example:
void DataEE_Read(int32 addr, int8 * ram, int bytes) {
int i;
for(i=0;i
#type default=
42
//emi is the addressmod name defined
Data Definitions
Using Program Memory for Data
CCS C Compiler provides a few different ways to use program memory for data. The different ways
are discussed below:
Constant Data:
The CONST qualifier will place the variables into program memory. If the keyword CONST is used
before the identifier, the identifier is treated as a constant. Constants should be initialized and may
not be changed at run-time. This is an easy way to create lookup tables.
The ROM Qualifier puts data in program memory with 3 bytes per instruction space. The address
used for ROM data is not a physical address but rather a true byte address. The & operator can be
used on ROM variables however the address is logical not physical.
The syntax is:
const type id[cexpr] = {value}
For example:
Placing data into ROM
const int table[16]={0,1,2...15}
Placing a string into ROM
const char cstring[6]={"hello"}
Creating pointers to constants
const char *cptr;
cptr = string;
The #org preprocessor can be used to place the constant to specified address blocks.
For example:
The constant ID will be at 1C00.
#ORG 0x1C00, 0x1C0F
CONST CHAR ID[10]= {"123456789"};
Note: Some extra code will precede the 123456789.
The function label_address can be used to get the address of the constant. The constant variable
can be accessed in the code. This is a great way of storing constant data in large programs.
Variable length constant strings can be stored into program memory.
A special method allows the use of pointers to ROM. This method does not contain extra code at
the start of the structure as does constant..
For example:
char rom commands[] = {“put|get|status|shutdown”};
The compiler allows a non-standard C feature to implement a constant array of variable length
strings.
The syntax is:
const char id[n] [*] = { "string", "string" ...};
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C Compiler Reference Manual August 2009
Where n is optional and id is the table identifier.
For example:
const char colors[] [*] = {"Red", "Green", "Blue"};
#ROM directive:
Another method is to use #rom to assign data to program memory.
The syntax is:
#rom address = {data, data, … , data}
For example:
Places 1,2,3,4 to ROM addresses starting at 0x1000
#rom 0x1000 = {1, 2, 3, 4}
Places null terminated string in ROM
#rom 0x1000={"hello"}
This method can only be used to initialize the program memory.
Built-in-Functions:
The compiler also provides built-in functions to place data in program memory, they are:
• write_program_eeprom(address,data);
- Writes data to program memory
• write_program_memory(address, dataptr, count);
- Writes count bytes of data from dataptr to address in program memory.
- Every fourth byte of data will not be written, fill with 0x00.
Please refer to the help of these functions to get more details on their usage and limitations
regarding erase procedures. These functions can be used only on chips that allow writes to
program memory. The compiler uses the flash memory erase and write routines to implement the
functionality.
The data placed in program memory using the methods listed above can be read from width the
following functions:
• read_program_memory((address, dataptr, count)
- Reads count bytes from program memory at address to RAM at dataptr. Every
fourth byte of data is read as 0x00
These functions can be used only on chips that allow reads from program memory. The compiler
uses the flash memory read routines to implement the functionality.
44
Data Definitions
Function Definition
The format of a function definition is as follows:
[qualifier] id
( [type-specifier id] )
{ [stmt] }
Optional See Below
Zero or more comma separated.
See Data Types
Zero or more Semi-colon
separated. See Statements.
The qualifiers for a function are as follows:
• VOID
• type-specifier
• #separate
• #inline
• #int_..
When one of the above are used and the function has a prototype (forward declaration of the
function before it is defined) you must include the qualifier on both the prototype and function
definition.
A (non-standard) feature has been added to the compiler to help get around the problems created
by the fact that pointers cannot be created to constant strings. A function that has one CHAR
parameter will accept a constant string where it is called. The compiler will generate a loop that will
call the function once for each character in the string.
Example:
void lcd_putc(char c ) {
...
}
lcd_putc ("Hi There.");
45
FUNCTIONAL OVERVIEWS
I2C
I2C™ is a popular two-wire communication protocol developed by Phillips. Many PIC microcontrollers
support hardware-based I2C™. CCS offers support for the hardware-based I2C™ and a softwarebased master I2C™ device. (For more information on the hardware-based I2C module, please
consult the datasheet for you target device; not all PICs support I2C™.)
Relevant Functions:
i2c_start()
i2c_write(data)
i2c_read()
i2c_stop()
i2c_poll()
Relevant Preprocessor:
#use i2c
Relevant Interrupts:
#INT_SSP
#INT_BUSCOL
#INT_I2C
#INT_BUSCOL2
#INT_SSP2
Relevant Include Files:
None, all functions built-in
Relevant getenv() Parameters:
I2C_SLAVE
I2C_MASTER
Example Code:
#define Device_SDA PIN_C3
#define Device_SLC PIN_C4
#use i2c(master, sda=Device_SDA,
scl=Device_SCL)
..
..
BYTE data;
i2c_start();
i2c_write(data);
i2c_stop();
Issues a start command when in the I2C master mode.
Sends a single byte over the I2C interface.
Reads a byte over the I2C interface.
Issues a stop command when in the I2C master mode.
Returns a TRUE if the hardware has received a byte in the buffer.
Configures the compiler to support I2C™ to your specifications.
I2C or SPI activity
Bus Collision
I2C Interrupt (Only on 14000)
Bus Collision (Only supported on some PIC18's)
I2C or SPI activity (Only supported on some PIC18's)
Returns a 1 if the device has I2C slave H/W
Returns a 1 if the device has a I2C master H/W
// Pin defines
// Configure Device as Master
// Data to be transmitted
// Issues a start command when in the I2C master mode.
// Sends a single byte over the I2C interface.
//Issues a stop command when in the I2C master mode.
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ADC
These options let the user configure and use the analog to digital converter module. They are only
available on devices with the ADC hardware. The options for the functions and directives vary
depending on the chip and are listed in the device header file. On some devices there are two
independent ADC modules, for these chips the second module is configured using secondary ADC
setup functions (Ex. setup_ADC2).
Relevant Functions:
setup_adc(mode)
setup_adc_ports(value)
set_adc_channel(channel)
read_adc(mode)
ADC_done()
Relevant Preprocessor:
#DEVICE ADC=xx
Sets up the a/d mode like off, the adc clock etc.
Sets the available adc pins to be analog or digital.
Specifies the channel to be use for the a/d call.
Starts the conversion and reads the value. The mode can
also control the functionality.
Returns 1 if the ADC module has finished its conversion.
Configures the read_adc return size. For example, using
a PIC with a 10 bit A/D you can use 8 or 10 for xx- 8 will
return the most significant byte, 10 will return the full A/D
reading of 10 bits.
Relevant Interrupts:
INT_AD
INT_ADOF
Interrupt fires when a/d conversion is complete
Interrupt fires when a/d conversion has timed out
Relevant Include Files:
None, all functions built-in
Relevant getenv() parameters:
ADC_CHANNELS
ADC_RESOLUTION
Number of A/D channels
Number of bits returned by read_adc
Example Code:
#DEVICE ADC=10
...
long value;
...
setup_adc(ADC_CLOCK_INTERNAL);
setup_adc_ports(ALL_ANALOG);
set_adc_channel(0);
delay_us(10);
48
//enables the a/d module
//and sets the clock to internal adc clock
//sets all the adc pins to analog
//the next read_adc call will read channel 0
//a small delay is required after setting the channel
//and before read
Functional Overviews
value=read_adc();
read_adc(ADC_START_ONLY);
value=read_adc(ADC_READ_ONLY);
//starts the conversion and reads the result
//and store it in value
//only starts the conversion
//reads the result of the last conversion and store it in value.
Assuming the device hat a 10bit ADC module, value will
range between 0-3FF. If #DEVICE ADC=8 had been used
instead the result will yield 0-FF. If #DEVICE ADC=16 had
been used instead the result will yield 0-FFC0
Analog Comparator
These functions sets up the analog comparator module. Only available in some devices.
Relevant Functions:
setup_comparator(mode)
Enables and sets the analog comparator module. The
options vary depending on the chip, please refer to the
header file for details.
Relevant Preprocessor:
None
Relevant Interrupts:
INT_COMP
Interrupt fires on comparator detect. Some chips have more
than one comparator unit, and hence more interrupts.
Relevant Include Files:
None, all functions built-in
Relevant getenv() parameters:
COMP
Returns 1 if the device has comparator
Example Code:
For PIC12F675
setup_adc_ports(NO_ANALOGS);
setup_comparator(A0_A1_OUT_ON_A2);
// all pins digital
//a0 and a1 are analog comparator inputs and a2 is
the
// outputif (C1OUT)
//true when comparator output is high
//output_low(pin_a4); else output_high(pin_a4);
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CAN Bus
These functions allow easy access to the Controller Area Network (CAN) features included with the
MCP2515 CAN interface chip and the PIC18 MCU. These functions will only work with the MCP2515
CAN interface chip and PIC microcontroller units containing either a CAN or an ECAN module. Some
functions are only available for the ECAN module and are specified by the work ECAN at the end of
the description. The listed interrupts are no available to the MCP2515 interface chip.
Relevant Functions:
can_init(void);
can_set_baud(void);
can_set_mode
(CAN_OP_MODE mode);
can_set_functional_mode
(CAN_FUN_OP_MODE mode);
can_set_id(int* addr, int32 id, int1 ext);
can_get_id(int * addr, int1 ext);
can_putd
(int32 id, int * data, int len,
int priority, int1 ext, int1 rtr);
can_getd
(int32 & id, int * data, int & len,
struct rx_stat & stat);
can_enable_rtr(PROG_BUFFER b);
can_disable_rtr(PROG_BUFFER b);
can_load_rtr
(PROG_BUFFER b, int * data, int len);
can_enable_filter(long filter);
can_disable_filter(long filter);
can_associate_filter_to_buffer
(CAN_FILTER_ASSOCIATION_BUFFERS
buffer,CAN_FILTER_ASSOCIATION filter);
50
Initializes the CAN module to 125k baud and clears all
the filters and masks so that all messages can be
received from any ID.
Initializes the baud rate of the CAN bus to 125kHz. It
is called inside the can_init() function so there is no
need to call it.
Allows the mode of the CAN module to be changed to
configuration mode, listen mode, loop back mode,
disabled mode, or normal mode.
Allows the functional mode of ECAN modules to be
changed to legacy mode, enhanced legacy mode, or
first in firstout (fifo) mode. ECAN
Can be used to set the filter and mask ID's to the
value specified by addr. It is also used to set the ID of
the message to be sent.
Returns the ID of a received message.
Constructs a CAN packet using the given arguments
and places it in one of the available transmit buffers.
Retrieves a received message from one of the CAN
buffers and stores the relevant data in the referenced
function parameters.
Enables the automatic response feature which
automatically sends a user created packet when a
specified ID is received. ECAN
Disables the automatic response feature. ECAN
Creates and loads the packet that will automatically
transmitted when the triggering ID is received. ECAN
Enables one of the extra filters included in the ECAN
module. ECAN
Disables one of the extra filters included in the ECAN
module. ECAN
Used to associate a filter to a specific buffer. This
allows only specific buffers to be filtered and is
available in the ECAN module. ECAN
Functional Overviews
can_associate_filter_to_mask
(CAN_MASK_FILTER_ASSOCIATE mask,
CAN_FILTER_ASSOCIATION filter);
can_fifo_getd(int32 & id,int * data,
int &len,struct rx_stat & stat);
Relevant Preprocessor:
None
Relevant Interrupts:
#int_canirx
#int_canwake
#int_canerr
#int_cantx0
#int_cantx1
#int_cantx2
#int_canrx0
#int_canrx1
Relevant Include Files:
can-mcp2510.c
can-18xxx8.c
can-18F4580.c
Relevant getenv() Parameters:
none
Example Code:
can_init();
can_putd(0x300,data,8,3,TRUE,FALSE);
can_getd(ID,data,len,stat);
Used to associate a mask to a specific buffer. This
allows only specific buffer to have this mask applied.
This feature is available in the ECAN module. ECAN
Retrieves the next buffer in the fifo buffer. Only
available in the ECON module while operating in fifo
mode. ECAN
This interrupt is triggered when an invalid packet is
received on the CAN.
This interrupt is triggered when the PIC is woken up
by activity on the CAN.
This interrupt is triggered when there is an error in the
CAN module.
This interrupt is triggered when transmission from
buffer 0 has completed.
This interrupt is triggered when transmission from
buffer 1 has completed.
This interrupt is triggered when transmission from
buffer 2 has completed.
This interrupt is triggered when a message is received
in buffer 0.
This interrupt is triggered when a message is received
in buffer 1.
Drivers for the MCP2510 and MCP2515 interface chips
Drivers for the built in CAN module
Drivers for the build in ECAN module
// initializes the CAN bus
// places a message on the CAN buss with
// ID = 0x300 and eight bytes of data pointed to by
// “data”, the TRUE creates an extended ID, the
// FALSE creates
// retrieves a message from the CAN bus storing the
// ID in the ID variable, the data at the array pointed to by
// “data', the number of data bytes in len, and statistics
// about the data in the stat structure.
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C Compiler Reference Manual August 2009
CCP1
These options lets to configure and use the CCP module. There might be multiple CCP modules for
a device. These functions are only available on devices with CCP hardware. They operate in 3
modes: capture, compare and PWM. The source in capture/compare mode can be timer1 or timer3
and in PWM can be timer2 or timer4. The options available are different for different devices and
are listed in the device header file. In capture mode the value of the timer is copied to the CCP_X
register when the input pin event occurs. In compare mode it will trigger an action when timer and
CCP_x values are equal and in PWM mode it will generate a square wave.
Relevant Functions:
setup_ccp1(mode)
set_pwm1_duty(value)
Sets the mode to capture, compare or PWM. For capture
The value is written to the pwm1 to set the duty.
Relevant Preprocessor:
None
Relevant Interrupts :
INT_CCP1
Interrupt fires when capture or compare on CCP1
Relevant Include Files:
None, all functions built-in
Relevant getenv() parameters:
CCP1
Example Code:
#int_ccp1
void isr()
{
rise = CCP_1;
fall = CCP_2;
pulse_width = fall - rise;
}
..
setup_ccp1(CCP_CAPTURE_RE);
setup_ccp2(CCP_CAPTURE_FE);
setup_timer_1(T1_INTERNAL);
Returns 1 if the device has CCP1
//CCP_1 is the time the pulse went high
//CCP_2 is the time the pulse went low
//pulse width
// Configure CCP1 to capture rise
// Configure CCP2 to capture fall
// Start timer 1
Some chips also have fuses which allows to multiplex the ccp/pwm on different pins. So check the
fuses to see which pin is set by default. Also fuses to enable/disable pwm outputs.
52
Functional Overviews
CCP2, CCP3, CCP4, CCP5, CCP6
Similar to CCP1
Configuration Memory
On all pic18s the configuration memory is readable and writable. This functionality is not available
on pic16s.
Relevant Functions:
write_configuration_memory
(ramaddress, count)
or
write_configuration_memory
(offset,ramaddress, count)
read_configuration_memory
(ramaddress,count)
Writes count bytes, no erase needed
Writes count bytes, no erase needed starting at byte
address offset
Read count bytes of configuration memory
Relevant Preprocessor:
None
Relevant Include Files:
None, all functions built-in
Relevant getenv() parameters:
None
Example Code:
For PIC18f452
int16 data=0xc32;
...
write_configuration_memory(data,2);
//writes 2 bytes to the configuration memory
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C Compiler Reference Manual August 2009
DAC
These options let the user configure and use the digital to analog converter module. They are only
available on devices with the DAC hardware. The options for the functions and directives vary
depending on the chip and are listed in the device header file.
Relevant Functions:
setup_adc(divisor)
Sets up the DAC e.g. Reference voltages
dac_write(value)
Writes the 8-bit value to the DAC module
Relevant Preprocessor:
#use delay
Relevant Interrupts:
None
Relevant Include Files:
None, all functions built-in
Relevant getenv()
parameters:
None
Example Code:
int16 i = 0;
setup_dac(DAC_RIGHT_ON,
5);
While(1){
i++;
dac_write(DAC_RIGHT, i);
}
54
Must add an auxiliary clock in the #use delay preprocessor. For
example:
#use delay(clock=20M, Aux: crystal=6M, clock=3M)
//enables the d/a module with right channel enabled and a division
of the clock by 5
//writes i to the right DAC channel
Functional Overviews
Data Eeprom
The data eeprom memory is readable and writable in some chips. These options lets the user read
and write to the data eeprom memory. These functions are only available in flash chips.
Relevant Functions:
(8 bit or 16 bit depending on the device)
Reads the data EEPROM memory location
read_eeprom(address)
write_eeprom(address, value)
Erases and writes value to data EEPROM location address.
Relevant Preprocessor:
#ROM address={list}
Can also be used to put data EEPROM memory data into the
hex file.
WRITE_EEPROM = NOINT
Allows interrupts to occur while the write_eeprom()
operations is polling the done bit to check if the write
operations has completed. Can be used as long as no
EEPROM operations are performed during an ISR.
Relevant Interrupts:
INT_EEPROM
Interrupt fires when EEPROM write is complete
Relevant Include Files:
None, all functions built-in
Relevant getenv() parameters:
DATA_EEPROM
Example Code:
For 18F452
#rom 0xf00000={1,2,3,4,5}
write_eeprom(0x0,0x12);
value=read_eeprom(0x0);
#ROM 0x007FFC00={1,2,3,4,5}
write_eeprom(0x10, 0x1337);
value=read_eeprom(0x0);
Size of data EEPROM memory.
//inserts this data into the hex file. The data eeprom address
differs for
//different family of chips. Please refer to the programming
specs to
//find the right value for the device.
//writes 0x12 to data eeprom location 0
//reads data eeprom location 0x0 returns 0x12
// Inserts this data into the hex file
// The data EEPROM address differs between PICs
// Please refer to the device editor for device specific values.
// Writes 0x1337 to data EEPROM location 10.
// Reads data EEPROM location 10 returns 0x1337.
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C Compiler Reference Manual August 2009
External Memory
Some pic18s have the external memory functionality where the external memory can be mapped to
external memory devices like(Flash, EPROM or RAM). These functions are available only on
devices that support external memory bus.
Relevant Functions:
setup_external_memory(mode)
read_external_memory
(address, dataptr,count)
write_external_memory
(address_dataptr,count)
Sets the mode of the external memory bus refer to the
device header file for available constants.
Reads count bytes to dataptr form address.
Writes count bytes from dataptr to address
These functions don't use any flash/eeprom write algorithm. The data is only copied to/from register
data address space to/from program memory address space.
Relevant Preprocessor:
None
Relevant Interrupts :
None
Relevant Include Files:
None, all functions built-in
Relevant getenv() parameters:
None
Example Code:
write_external_memory(0x20000,data,2);
read_external_memory(0x20000,value,2)
56
//writes2 bytes form data to 0x20000(starting address of
// external memory)
//reads 2 bytes from 0x20000 to value
Functional Overviews
General Purpose I/O
These options let the user configure and use the I/O pins on the device. These functions will affect
the pins that are listed in the device header file.
Relevant Functions:
Sets the given pin to high state.
output_high(pin)
output_low(pin)
Sets the given pin to the ground state.
output_float(pin)
Sets the specified pin to the output mode. This will allow the
pin to float high to represent a high on an open collector type
of connection.
output_x(value)
Outputs an entire byte to the port.
output_bit(pin,value)
Outputs the specified value (0,1) to the specified I/O pin.
input(pin)
The function returns the state of the indicated pin.
input_state(pin)
This function reads the level of a pin without changing the
direction of the pin as INPUT() does.
set_tris_x(value)
Sets the value of the I/O port direction register. A '1' is an input
and '0' is for output.
Relevant Preprocessor:
#use standard_io (port)
This compiler will use this directive be default and it will
automatically inserts code for the direction register whenever
an I/O function like output_high() or input() is used.
#use fast_io (port)
This directive will configure the I/O port to use the fast method
of performing I/O. The user will be responsible for setting the
port direction register using the set_tris_x() function.
#use fixed_io
This directive set particular pins to be used an input or output, and
(port_outputs=;in,pin?)
the compiler will perform this setup every time this pin is used.
Relevant Interrupts:
None
Relevant Include Files:
None, all functions built-in
Relevant getenv() parameters:
PIN:pb
Returns a 1 if bit b on port p is on this part
Example Code:
#use fast_io(b)
...
Int8 Tris_value= 0x0F;
int1 Pin_value;
...
set_tris_b(Tris_value);
output_high(PIN_B7);
If(input(PIN_B0)){
//Sets B0:B3 as input and B4:B7 as output
//Set the pin B7 to High
//Read the value on pin B0, set B7 to low if pin
B0 is high
output_high(PIN_B7)
;}
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C Compiler Reference Manual August 2009
Internal LCD
Some families of PICmicro controllers can drive an LCD glass directly, without the need of an LCD
controller. For example, the PIC16C926, PIC16F916 and the PIC18F8490 have an internal LCD
controller.
Relevant Functions:
Configures the LCD module to use the specified segments, specified
setup_lcd
(mode, prescale,
mode and specified timer prescalar. For more information on valid
segments)
modes see the setup_lcd() manual page and the .H header file for your
PICmicro controller.
lcd_symbol
(symbol, segment_b7 ..
segment_b0)
lcd_load(ptr, offset, len)
The specified symbol is placed on the desired segments. For example,
if bit0 of symbol is is set, then segment_b0 is set. segment_b7 to
segment_b0 represent the SEGXX pin on the PICmicro. In this
example, if bit0 of symbol is set and segment_b0 is 15, then SEG15
would be set.
Writes len bytes of data from ptr directly to the LCD segment memory,
starting with offset.
Relevant Preprocessor:
None
Relevant Interrupts:
#int_lcd
LCD frame is complete, all pixels displayed
Relevant Inlcude Files:
None, all functions built-in to the compiler.
Relevant getenv() Parameters:
LCD
Returns TRUE if the device has an internal LCD controller.
Example Program:
//how each segment is set (on or off) for ascii digits 0 to 9.
byte CONST DIGIT_MAP[10]={0X90,0XB7,0X19,0X36, 0X54,0X50,0XB5,0X24};
//define the segment information for the 1st digit of the glass LCD.
//in this example the first segment uses the second seg signal on COM0
#define DIGIT_1_CONFIG COM0+2,COM0+4,COM0+5, COM2+4,COM2+1, COM1+4,COM1+5
//display digits 1 to 9 on the first digit of the LCD
for(i=1; i<=9; ++i) {
LCD_SYMBOL(DIGIT_MAP[i],DIGIT_1_CONFIG);
delay_ms(1000);
}
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Functional Overviews
Internal Oscillator
Many chips have internal oscillator. There are different ways to configure the internal oscillator.
Some chips have a constant 4 Mhz factory calibrated internal oscillator. The value is stored in
some location (mostly the highest program memory) and the compiler moves it to the osccal
register on startup. The programmers save and restore this value but if this is lost they need to be
programmed before the oscillator is functioning properly. Some chips have factory calibrated
internal oscillator that offers software selectable frequency range(from 31Kz to 8 Mhz) and they
have a default value and can be switched to a higher/lower value in software. They are also
software tunable. Some chips also provide the PLL option for the internal oscillator.
Relevant Functions:
setup_oscillator(mode,
finetune)
Sets the value of the internal oscillator and also tunes it. The
options vary depending on the chip and are listed in the device
header files.
Relevant Preprocessor:
None
Relevant Interrupts:
INT_OSC_FAIL or INT_OSCF
Interrupt fires when the system oscillator fails and the processor
switches to the internal oscillator.
Relevant Include Files:
None, all functions built-in
Relevant getenv() parameters:
None
Example Code:
For PIC18F8722
setup_oscillator(OSC_32MHZ);
//sets the internal oscillator to 32MHz (PLL enabled)
If the internal oscillator fuse option are specified in the #fuses and a valid clock is specified in the
#use delay(clock=xxx) directive the compiler automatically sets up the oscillator. The #use delay
statements should be used to tell the compiler about the oscillator speed.
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C Compiler Reference Manual August 2009
Interrupts
The following functions allow for the control of the interrupt subsystem of the microcontroller. With
these functions, interrupts can be enabled, disabled, and cleared. With the preprocessor directives,
a default function can be called for any interrupt that does not have an associated isr, and a global
function can replace the compiler generated interrupt dispatcher.
Relevant Functions:
disable_interrupts()
Disables the specified interrupt.
enable_interrupts()
Enables the specified interrupt.
ext_int_edge()
Enables the edge on which the edge interrupt should trigger. This
can be either rising or falling edge.
clear_interrupt()
This function will clear the specified interrupt flag. This can be used
if a global isr is used, or to prevent an interrupt from being serviced.
Relevant Preprocessor:
#device high_ints=
#int_xxx fast
Relevant Interrupts:
#int_default
This directive tells the compiler to generate code for high priority
interrupts.
This directive tells the compiler that the specified interrupt should be
treated as a high priority interrupt.
This directive specifies that the following function should be called if
an interrupt is triggered but no routine is associated with that
interrupt.
#int_global
This directive specifies that the following function should be called
whenever an interrupt is triggered. This function will replace the
compiler generated interrupt dispatcher.
#int_xxx
This directive specifies that the following function should be called
whenever the xxx interrupt is triggered. If the compiler generated
interrupt dispatcher is used, the compiler will take care of clearing
the interrupt flag bits.
Relevant Include Files:
none, all functions built in.
Relevant getenv() Parameters:
none
Example Code:
#int_timer0
void timer0interrupt()
// #int_timer associates the following function with the
// interrupt service routine that should be called
enable_interrupts(TIMER0);
// enables the timer0 interrupt
disable_interrtups(TIMER0);
// disables the timer0 interrupt
clear_interrupt(TIMER0);
// clears the timer0 interrupt flag
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Functional Overviews
Linker
The linker allows allows multiple files to be compiled into multiple objects (.o files) and finally linked
together to form a final .hex file. The linker can be used from inside the PCW IDE, through the
MPLAB IDE and from the command line.
CCS provides an example that demonstrates the use of the linker in the mcu.zip files present in the
Examples folder. The files in this project are as follows:
main.c
filter.c
report.c
project.h
filter.h
report.h
buildall.bat
build.bat
project.pjt
Primary file for the first compilation unit
Primary file for the second compilation
Primary file for the third compilation unit
Include file with project wide definitions
External definitions for filter, should be
External definitions for report, should be
Batch file that compiles and links all units
Batch file that recompiles files needing
Used by build.bat to list project units
See MCU Documentation.pdf for detailed information on these files.
Each unit will produce a .o (relocatable object) file, which gets linked together to form the final load
image (project.hex)
Building the project from the command line:
1. Move the project files into a directory.
2. Edit the Buildall.bat file and make sure the path to CCSC.EXE is correct.
3. From a DOS prompt set the default directory to the project directory.
4. Enter: BUILDALL
"c:\program files\picc\ccsc" +FM +EXPORT report.c
"c:\program files\picc\ccsc" +FM +EXPORT filter.c
"c:\program files\picc\ccsc" +FM +EXPORT main.c
"c:\program files\picc\ccsc" +FM LINK="project.hex=report.o,filter.o,main.o"
Automatically building by recompiling needed files:
1. The required lines in the project.pjt file are:
[Units]
Count=3
1=filter.o
2=report.o
3=main.o
Link=1
2. From a DOS prompt set the default directory to the project directory.
3. Enter: BUILD
Note that after a project is linked if no .pjt file exists the linker will create one that may be used with
the BUILD= option in the future.
"c:\program files\picc\ccsc" +FM BUILD=project.pjt
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Replacing the linker command line with a linker script:
1. Create a file named project.c with the following lines:
#import( report.o )
#import( filter.o )
#import( main.o )
2. Compile each unit (report, filter, main).
3. Compile project.c
Using the IDE to work with multiple compilation units:
·
·
·
·
·
62
The above screen is from OPTIONS > PROJECT OPTIONS after loading the project.pjt file.
If the file does not exist create the project manually and make screen like the above.
The pane to the left is the FILES slide out that is available from VIEW > PROJECT FILES.
Right click on a unit name (like filter) select COMPILE to compile just that unit.
Click on the build icon (third from the right) to rebuild and link the whole project.
This pane is helpful in managing each unit in the project. Review the right click options for
the full range of options.
Functional Overviews
Using MPLAB IDE to work with Multiple Compilation Units
· Create a new project by selecting “Project -> New” from the toolbar. Follow the dialog boxes to
specify the project name and project path.
· Make sure MPLAB is configured for the proper chip, as the CCS C compiler uses this selection
to determine which compiler to use (PCB, PCM, PCH, PCD, etc). The chip can be selected using
“Configure -> Select Device” from the MPLAB toolbar.
·
·
·
·
·
·
·
Add source files by either a.) right clicking on 'Source Files' in the MPLAB Project window or
b.) selecting “Project -> Add New File to Project..” from the MPLAB toolbar.
Performing a Make (hotkey is F10) or Build All will compile the source files separately, and link
the .o files in the final step. Make only compiles files that have changed, Build All will delete all
intermediate files first and then compile all files regardless if they have changed since last build
An individual unit can be compiled by right clicking on the file in the MPLAB Project window
and choosing 'Compile.' This will not re-link the project when it is done compiling this unit.
An already compiled .o file can be added to the project, and will be linked during the Make/Build process.
If there is only one source in the project, it will be compiled and linked in one phase (no .o file will
be created).
Many project build options (such as output directory, include directories, output files generated, etc)
can be changed by selecting "Project -> Build Options“ from the MPLAB toolbar.
If the compile fails with an error that says something like “Target chip not supported” or
“Compiler not found” make sure that
a.) you have the proper PIC selected (use “Configure -> Select Device” from the MPLAB toolbar),
b.) the CCS C Toolsuite has been selected for this project (use “Project -> Set Language
Toolsuite” from the MPLAB toolbar) and
c.) the path for CCSC.EXE is configured correctly for your installation of the CCS C Compiler
(use “Project -> Set Language Tool Locations” on the MPLAB toolbar)
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C Compiler Reference Manual August 2009
Notes
· By default variables declared at the unit level (outside a function) are visible to all other units.
To make a variable private to the unit use the keyword static. Notice report.c defines the
variable report_line_number. If the definition were changed to look as the following line then
there would be a link time error since main.c attempts to use the variable.
static long report_line_number;
·
·
·
·
·
·
·
This same rule applies to functions. Use static to make a function local to the unit.
Should two units have a function or unit level variable with the same name an error is
generated unless one of the following is true:
· The identifier is qualified with static.
· The argument list is different and two instances of the function can co-exist in the
project in accordance with the normal overload rules.
· The contents of the functions are absolutely identical. In this case the CCS linker
simply deletes the duplicate function.
The standard C libraries (like stdlib.h) are supplied with source code in the .h file. Because of
the above rule these files may be #include'd in multiple units without taking up extra ROM and
with no need to include these in the link command since they are not units.
#define's are never exported to other units. If a #define needs to be shared between units put
them in an include file that is #include'd by both units. Project wide defines in our example
could go into project.h.
It is best to have an include file like project.h that all units #include. This file should define the chip,
speed, fuses and any other compiler settings that should be the same for all units in the project.
In this example project a #USE RS232 is in the project.h file. This creates an RS232 library in
each unit. The linker is able to determine the libraries are the same and the duplicates
removed in the final link.
Each unit has its own error file (like filter.err). When the compilations are done in a batch file it
may be useful to terminate the batch run on the first error. The +CC command line option will
cause the compiler to return a windows error code if the compilation fails. This can be tested
in the batch file like this:
"c:\program files\picc\ccsc" +FM +CC +EXPORT report.c
if not errorlevel 1 goto abort ...
goto end
:abort
echo COMPILE ERROR
:end
64
Functional Overviews
Low Voltage Detect
These functions configure the high/low voltage detect module. Functions available on the chips that
have the low voltage detect hardware.
Relevant Functions:
setup_low_volt_detect(mode)
Sets the voltage trigger levels and also the mode (below or
above in case of the high/low voltage detect module). The
options vary depending on the chip and are listed in the
device header files.
Relevant Preprocessor:
None
Relevant Interrupts :
INT_LOWVOLT
Interrupt fires on low voltage detect
Relevant Include Files:
None, all functions built-in
Relevant getenv() parameters:
None
Example Code:
For PIC18F8722
setup_low_volt_detect
(LVD_36|LVD_TRIGGER_ABOVE);
//sets the trigger level as 3.6 volts and
// trigger direction as above. The interrupt
//if enabled is fired when the voltage is
//above 3.6 volts.
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Power PWM
These options lets the user configure the Pulse Width Modulation (PWM) pins. They are only
available on devices equipped with PWM. The options for these functions vary depending on the
chip and are listed in the device header file.
Relevant Functions:
setup_power_pwm(config)
Sets up the PWM clock, period, dead time etc.
setup_power_pwm_pins(module x)
Configure the pins of the PWM to be in
Complimentary, ON or OFF mode.
set_power_pwmx_duty(duty)
Stores the value of the duty cycle in the
PDCXL/H register. This duty cycle value is the
time for which the PWM is in active state.
set_power_pwm_override(pwm,override,value)
This function determines whether the
OVDCONS or the PDC registers determine the
PWM output .
Relevant Preprocessor:
None
Relevant Interrupts:
#INT_PWMTB
PWM Timebase Interrupt (Only available on
PIC18XX31)
Relevant getenv() Parameters:
None
Example Code:
....
long duty_cycle, period;
...
// Configures PWM pins to be ON,OFF or in Complimentary mode.
setup_power_pwm_pins(PWM_COMPLEMENTARY ,PWM_OFF, PWM_OFF, PWM_OFF);
//Sets up PWM clock , postscale and period. Here period is used to set the
//PWM Frequency as follows:
//Frequency = Fosc / (4 * (period+1) *postscale)
setup_power_pwm(PWM_CLOCK_DIV_4|PWM_FREE_RUN,1,0,period,0,1,0);
set_power_pwm0_duty(duty_cycle));
66
// Sets the duty cycle of the PWM 0,1 in
//Complementary mode
Functional Overviews
Program Eeprom
The flash program memory is readable and writable in some chips and is just readable in some.
These options lets the user read and write to the flash program memory. These functions are only
available in flash chips.
Relevant Functions:
read_program_eeprom
(address)
write_program_eeprom
(address, value)
erase_program_eeprom
(address)
Reads the program memory location(16 bit or 32 bit
depending on the device).
Writes value to program memory location address.
Erases FLASH_ERASE_SIZE bytes in program
memory.
write_program_memory
address,dataptr,count)
Writes count bytes to program memory from dataptr
to address. When address is a mutiple of
FLASH_ERASE_SIZE an erase is also performed.
read_program_memory
(address,dataptr,count)
Read count bytes from program memory at address
to dataptr.
Relevant Preprocessor:
#ROM address={list}
#DEVICE(WRITE_EEPROM=ASYNC)
Relevant Interrupts:
INT_EEPROM
Can be used to put program memory data into the
hex file.
Can be used with #DEVICE to prevent the write
function from hanging. When this is used make sure
the eeprom is not written both inside and outside the
ISR.
Interrupt fires when eeprom write is complete.
Relevant Include Files:
None, all functions built-in
Relevant getenv() parameters
PROGRAM_MEMORY
READ_PROGRAM
FLASH_WRITE_SIZE
FLASH_ERASE_SIZE
Size of program memory
Returns 1 if program memory can be read
Smallest number of bytes written in flash
Smallest number of bytes erased in flash
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Example Code:
For 18F452 where the write size is 8 bytes and erase size is 64 bytes
#rom 0xa00={1,2,3,4,5}
//inserts this data into the hex file.
erase_program_eeprom(0x1000);
//erases 64 bytes strting at 0x1000
write_program_eeprom(0x1000,0x1234);
//writes 0x1234 to 0x1000
value=read_program_eeprom(0x1000);
//reads 0x1000 returns 0x1234
write_program_memory(0x1000,data,8);
//erases 64 bytes starting at 0x1000 as 0x1000 is a
multiple
//of 64 and writes 8 bytes from data to 0x1000
read_program_memory(0x1000,value,8);
//reads 8 bytes to value from 0x1000
erase_program_eeprom(0x1000);
//erases 64 bytes starting at 0x1000
write_program_memory(0x1010,data,8);
//writes 8 bytes from data to 0x1000
read_program_memory(0x1000,value,8);
//reads 8 bytes to value from 0x1000
For chips where getenv("FLASH_ERASE_SIZE") > getenv("FLASH_WRITE_SIZE")
WRITE_PROGRAM_EEPROM Writes 2 bytes,does not erase (use
ERASE_PROGRAM_EEPROM)
WRITE_PROGRAM_MEMORY Writes any number of bytes,will erase a block
whenever the first (lowest) byte in a block is written
to. If the first address is not the start of a block that
block is not erased.
ERASE_PROGRAM_EEPROM Will erase a block. The lowest address bits are not
used.
For chips where getenv("FLASH_ERASE_SIZE") = getenv("FLASH_WRITE_SIZE")
WRITE_PROGRAM_EEPROM Writes 2 bytes, no erase is needed.
WRITE_PROGRAM_MEMORY Writes any number of bytes, bytes outside the range
of the write block are not changed. No erase is
needed.
ERASE_PROGRAM_EEPROM Not available.
68
Functional Overviews
PSP
These options let to configure and use the Parallel Slave Port on the supported devices.
Relevant Functions:
setup_psp(mode)
psp_output_full()
psp_input_full
psp_overflow
Enables/disables the psp port on the chip
Returns 1 if the output buffer is full(waiting to be read by the
external bus)
Returns 1 if the input buffer is full(waiting to read by the cpu)
Returns 1 if a write occurred before the previously written byte
was read
Relevant Preprocessor:
None
Relevant Interrupts :
INT_PSP
Interrupt fires when PSP data is in
Relevant Include Files:
None, all functions built-in
Relevant getenv()
parameters:
PSP
Returns 1 if the device has PSP
Example Code:
while(psp_output_full());
psp_data=command;
while(!input_buffer_full());
if (psp_overflow())
error=true
else
data=psp_data;
//waits till the output buffer is cleared
//writes to the port
//waits till input buffer is cleared
//if there is an overflow set the error flag
//if there is no overflow then read the port
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C Compiler Reference Manual August 2009
PMP
The Parallel Master Port(PMP) is a parallel 8-bit I/O module specifically designed to communicate
with a wide variety of parallel devices. Key features of the PMP module are:
· 8 Data lines
· Up to 16 Programmable Address Lines
· Up to 2 Chip Select Lines
· Programmable Strobe option
· Address Auto-Increment/Auto-Decrement
· Programmable Address/Data Multiplexing
· Programmable Polarity on Control Signals
· Legacy Parallel Slave(PSP) Support
· Enhanced Parallel Slave Port Support
· Programmable Wait States
Relevant Functions:
setup_pmp
(options,address_mask)
setup_psp
(options,address_mask)
pmp_write ( data )
psp_write(address,data)/
psp_write(data)
pmp_read ( )
psp_read (address)/
psp_read()
pmp_address ( address );
pmp_overflow ( );
pmp_input_full ( );
psp_input_full ( );
pmp_output_full ( );
psp_output_full ( );
Relevant Preprocessor:
None
Relevant Interrupts :
#INT_PMP
Relevant Include Files:
None, all functions built-in
Relevant getenv() parameters:
None
70
This will setup the PMP module for various mode and specifies
which address lines to be used.
This will setup the PSP module for various mode and specifies
which address lines to be used.
Write the data byte to the next buffer location.
This will write a byte of data to the next buffer location or will write
a byte to the specified buffer location.
Reads a byte of data.
psp_read() will read a byte of data from the next buffer location
and psp_read ( address ) will read the buffer location address.
Configures the address register of the PMP module with the
destination address during Master mode operation.
This will return the status of the output buffer underflow bit.
This will return the status of the input buffers.
This will return the status of the input buffers.
This will return the status of the output buffers.
This will return the status of the output buffers.
Interrupt on read or write strobe
Functional Overviews
Example Code:
setup_pmp( PAR_ENABLE |
PAR_MASTER_MODE_1 |
PAR_STOP_IN_IDLE,0x00FF
);
Sets up Master mode with address lines PMA0:PMA7
If ( pmp_output_full ( ))
{
pmp_write(next_byte);
}
RS232 I/O
These functions and directives can be used for setting up and using RS232 I/O functionality.
Relevant Functions:
GETC() or GETCH
GETCHAR or FGETC
Gets a character on the receive pin(from the specified stream in
case of fgetc, stdin by default). Use KBHIT to check if the character
is available.
GETS() or FGETS
Gets a string on the receive pin(from the specified stream
in case of fgets, STDIN by default). Use GETC to receive each
character until return is encountered.
PUTC or PUTCHAR or
FPUTC
Puts a character over the transmit pin(on the specified stream in the
case of FPUTC, stdout by default)
PUTS or FPUTS
Puts a string over the transmit pin(on the specified stream in the case
of FPUTC, stdout by default). Uses putc to send each character.
PRINTF or FPRINTF
Prints the formatted string(on the specified stream in the case of
FPRINTF, stdout by default). Refer to the printf help for details on
format string.
KBHIT
Return true when a character is received in the buffer in case of
hardware RS232 or when the first bit is sent on the RCV pin in case
of software RS232. Useful for polling without waiting in getc.
SETUP_UART
(baud,[stream])
or
SETUP_UART_SPEED(
Used to change the baud rate of the hardware UART at run-time.
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C Compiler Reference Manual August 2009
baud,[stream])
Specifying stream is optional. Refer to the help for more advanced
options.
ASSERT(condition)
Checks the condition and if false prints the file name and line to
STDERR. Will not generate code if #define NODEBUG is used.
PERROR(message)
Prints the message and the last system error to STDERR.
Relevant Preprocessor:
#use rs232(options)
Relevant Interrupts:
INT_RDA
INT_TBE
This directive tells the compiler the baud rate and other options like
transmit, receive and enable pins. Please refer to the #use rs232
help for more advanced options. More than one RS232 statements
can be used to specify different streams. If stream is not specified
the function will use the
last #use rs232.
Interrupt fires when the receive data available
Interrupt fires when the transmit data empty
Some chips have more than one hardware uart, and hence more interrupts.
Relevant Include Files:
None, all functions built-in
Relevant getenv()
parameters:
UART – Returns the number of UARTs on this PIC
AUART – Returns true if this UART is an advanced UART
UART_RX – Returns the receive pin for the first UART on this PIC (see PIN_XX)
UART_TX – Returns the transmit pin for the first UART on this PIC
UART2_RX – Returns the receive pin for the second UART on this PIC
UART2_TX – Returns the transmit pin for the second UART on this PIC
Example Code:
/* configure and enable uart, use first hardware UART on PIC */
#use rs232(uart1, baud=9600)
/* print a string */
printf(“enter a character”);
/* get a character */
if (kbhit())
//wait until a character has been received
c = getc();
//read character from UART
72
Functional Overviews
RTOS
These functions control the operation of the CCS Real Time Operating System (RTOS). This
operating system is cooperatively multitasking and allows for tasks to be scheduled to run at
specified time intervals. Because the RTOS does not use interrupts, the user must be careful to
make use of the rtos_yield() function in every task so that no one task is allowed to run forever.
Relevant Functions:
rtos_run()
Begins the operation of the RTOS. All task management
tasks are implemented by this function.
rtos_terminate()
This function terminates the operation of the RTOS and
returns operation to the original program. Works as a
return from the rtos_run()function.
rtos_enable(task)
Enables one of the RTOS tasks. Once a task is enabled,
the rtos_run() function will call the task when its time
occurs. The parameter to this function is the name of task
to be enabled.
rtos_disable(task)
Disables one of the RTOS tasks. Once a task is disabled,
the rtos_run() function will not call this task until it is
enabled using rtos_enable(). The parameter to this
function is the name of the task to be disabled.
rtos_msg_poll()
Returns true if there is data in the task's message queue.
rtos_msg_read()
Returns the next byte of data contained in the task's
message queue.
rtos_msg_send(task,byte)
Sends a byte of data to the specified task. The data is
placed in the receiving task's message queue.
rtos_yield()
Called with in one of the RTOS tasks and returns control
of the program to the rtos_run() function. All tasks should
call this function when finished.
rtos_signal(sem)
Increments a semaphore which is used to broadcast the
availability of a limited resource.
rtos_wait(sem)
Waits for the resource associated with the semaphore to
become available and then decrements to semaphore to
claim the resource.
rtos_await(expre)
Will wait for the given expression to evaluate to true
before allowing the task to continue.
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C Compiler Reference Manual August 2009
rtos_overrun(task)
Will return true if the given task over ran its alloted time.
rtos_stats(task,stat)
Returns the specified statistic about the specified task.
The statistics include the minimum and maximum times
for the task to run and the total time the task has spent
running.
Relevant Preprocessor:
#use rtos(options) This directive is used to specify several different RTOS attributes including the
timer to use, the minor cycle time and whether or not statistics should be enabled.
#task(options) This directive tells the compiler that the following function is to be an RTOS task.
#task specifies the rate at which the task should be called, the maximum time the task shall be
allowed to run, and how large it's queue should be.
Relevant Interrupts:
none
Relevant Include Files:
none all functions are built in
Relevant getenv() Parameters:
none
Example Code:
#USE RTOS(timer=0,minor_cycle=20ms) // RTOS will use timer zero, minor cycle will be 20ms
...
int sem;
...
#TASK(rate=1s,max=20ms,queue=5)
// Task will run at a rate of once per second
void task_name();
// with a maximum running time of 20ms and
// a 5 byte queue
rtos_run();
// begins the RTOS
rtos_terminate();
// ends the RTOS
rtos_enable(task_name);
rtos_disable(task_name);
rtos_msg_send(task_name,5);
rtos_yield();
rtos_sigal(sem);
// enables the previously declared task.
// disables the previously declared task
// places the value 5 in task_names queue.
// yields control to the RTOS
// signals that the resource represented by sem is
available.
For more information on the CCS RTOS please
74
Functional Overviews
SPI
SPI™ is a fluid standard for 3 or 4 wire, full duplex communications named by Motorola. Most PIC
devices support most common SPI™ modes. CCS provides a support library for taking advantage
of both hardware and software based SPI™ functionality. For software support, see #use spi.
Relevant Functions:
setup_spi(mode)
setup_spi2
Configure the hardware SPI to the specified mode. The mode
configures setup_spi2(mode) thing such as master or slave mode, clock
speed and clock/data trigger configuration.
Note: for devices with dual SPI interfaces a second function, setup_spi2(), is provided to configure
the second interface.
spi_data_is_in()
spi_data_is_in2()
Returns TRUE if the SPI receive buffer has a byte of data.
spi_write(value)
spi_write2(value)
Transmits the value over the SPI interface. This will cause the data to
be clocked out on the SDO pin.
spi_read(value)
spi_read2(value)
Performs an SPI transaction, where the value is clocked out on the
SDO pin and data clocked in on the SDI pin is returned. If you just want
to clock in data then you can use spi_read() without a parameter.
Relevant Preprocessor:
None
Relevant Interrupts:
#int_sspA
#int_ssp2
Transaction (read or write) has completed on the indicated peripheral.
Relevant getenv() Parameters:
SPI
Returns TRUE if the device has an SPI peripheral
Example Code:
//configure the device to be a master, data transmitted on H-to-L clock transition
setup_spi(SPI_MASTER | SPI_H_TO_L | SPI_CLK_DIV_16);
spi_write(0x80);
value=spi_read();
value=spi_read(0x80);
//write 0x80 to SPI device
//read a value from the SPI device
//write 0x80 to SPI device the same time you are reading a value.
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Timer0
These options lets the user configure and use timer0. It is available on all devices and is always
enabled. The clock/counter is 8-bit on pic16s and 8 or 16 bit on pic18s. It counts up and also
provides interrupt on overflow. The options available differ and are listed in the device header file.
Relevant Functions:
setup_timer_0(mode)
set_timer0(value) or
set_rtcc(value)
Sets the source, prescale etc for timer0
Initializes the timer0 clock/counter. Value may be a 8 bit or 16 bit
depending on the device.
value=get_timer0
Returns the value of the timer0 clock/counter
Relevant Preprocessor:
None
Relevant Interrupts :
INT_TIMER0 or
INT_RTCC
Relevant Include Files:
None, all functions
built-in
Interrupt fires when timer0 overflows
Relevant getenv() parameters:
TIMER0
Returns 1 if the device has timer0
Example Code:
For PIC18F452
setup_timer_0(RTCC_INTERNAL|RTCC_DIV_2|RTCC_8_BIT);//sets the internal clock as source
//and prescale 2. At 20Mhz timer0
//will increment every 0.4us in this
//setup and overflows every
//102.4us
set_timer0(0);
//this sets timer0 register to 0
time=get_timer0();
//this will read the timer0 register
//value
76
Functional Overviews
Timer1
These options lets the user configure and use timer1. The clock/counter is 16-bit on pic16s and
pic18s. It counts up and also provides interrupt on overflow. The options available differ and are
listed in the device header file.
Relevant Functions:
setup_timer_1(mode)
set_timer1(value)
value=get_timer1
Disables or sets the source and prescale for
timer1
Initializes the timer1 clock/counter
Returns the value of the timer1 clock/counter
Relevant Preprocessor:
None
Relevant Interrupts:
INT_TIMER1
Interrupt fires when timer1 overflows
Relevant Include Files:
None, all functions built-in
Relevant getenv() parameters:
TIMER1
Example Code:
For PIC18F452
setup_timer_1(T1_DISABLED);
or
setup_timer_1(T1_INTERNAL|T1_DIV_BY_8);
set_timer1(0);
time=get_timer1();
Returns 1 if the device has timer1
//disables timer1
//sets the internal clock as source
//and prescale as 8. At 20Mhz timer1 will
increment
//every 1.6us in this setup and overflows every
//104.896ms
//this sets timer1 register to 0
//this will read the timer1 register value
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Timer2
These options lets the user configure and use timer2. The clock/counter is 8-bit on pic16s and
pic18s. It counts up and also provides interrupt on overflow. The options available differ and are
listed in the device header file.
Relevant Functions:
setup_timer_2
(mode,period,postscale)
Disables or sets the prescale, period and a postscale for
timer2
set_timer2(value)
Initializes the timer2 clock/counter
value=get_timer2
Returns the value of the timer2 clock/counter
Relevant Preprocessor:
None
Relevant Interrupts:
INT_TIMER2
Interrupt fires when timer2 overflows
Relevant Include Files:
None, all functions built-in
Relevant getenv() parameters:
TIMER2
Example Code:
For PIC18F452
setup_timer_2(T2_DISABLED);
or
setup_timer_2(T2_DIV_BY_4,0xc0,2);
set_timer2(0);
time=get_timer2();
78
Returns 1 if the device has timer2
//disables timer2
//sets the prescale as 4, period as 0xc0 and postscales as
2.
//At 20Mhz timer2 will increment every .8us in this
//setup overflows every 154.4us and interrupt every
308.2us
//this sets timer2 register to 0
//this will read the timer1 register value
Functional Overviews
Timer3
Timer3 is very similar to timer1. So please refer to the timer1 section for more details.
Timer4
Timer4 is very similar to timer2. So please refer to the timer2 section for more details.
Timer5
These options lets the user configure and use timer5. The clock/counter is 16-bit and is available
only on 18Fxx31 devices. It counts up and also provides interrupt on overflow. The options
available differ and are listed in the device header file.
Relevant Functions:
setup_timer_5(mode)
set_timer5(value)
value=get_timer5
Disables or sets the source and prescale for timer5
Initializes the timer5 clock/counter
Returns the value of the timer51 clock/counter
Relevant Preprocessor:
None
Relevant Interrupts :
INT_TIMER5
Interrupt fires when timer5 overflows
Relevant Include Files:
None, all functions built-in
Relevant getenv() parameters:
TIMER5
Returns 1 if the device has timer5
Example Code:
For PIC18F4431
setup_timer_5(T5_DISABLED)
or
setup_timer_5(T5_INTERNAL|T5_DIV_BY_1);
set_timer5(0);
time=get_timer5();
//disables timer5
//sets the internal clock as source and prescale as 1.
//At 20Mhz timer5 will increment every .2us in this
//setup and overflows every 13.1072ms
//this sets timer5 register to 0
//this will read the timer5 register value
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USB
Universal Serial Bus, or USB, is used as a method for peripheral devices to connect to and talk to a
personal computer. CCS provides libraries for interfacing a PIC to PC using USB by using a PIC
with an internal USB peripheral (like the PIC16C765 or the PIC18F4550 family) or by using any PIC
with an external USB peripheral (the National USBN9603 family).
Relevant Functions:
usb_init()
Initializes the USB hardware. Will then wait in an infinite loop for the
USB peripheral to be connected to bus (but that doesn't mean it has
been enumerated by the PC). Will enable and use the USB interrupt.
usb_init_cs()
The same as usb_init(), but does not wait for the device to be connected
to the bus. This is useful if your device is not bus powered and can
operate without a USB connection.
usb_task()
If you use connection sense, and the usb_init_cs() for initialization, then
you must periodically call this function to keep an eye on the connection
sense pin. When the PIC is connected to the BUS, this function will then
perpare the USB peripheral. When the PIC is disconnected from the
BUS, it will reset the USB stack and peripheral. Will enable and use the
USB interrupt.
Note: In your application you must define USB_CON_SENSE_PIN to the connection sense pin.
usb_detach()
Removes the PIC from the bus. Will be called automatically by
usb_task() if connection is lost, but can be called manually by the user.
usb_attach()
Attaches the PIC to the bus. Will be called automatically by usb_task()
if connection is made, but can be called manually by the user.
usb_attached()
If using connection sense pin (USB_CON_SENSE_PIN), returns TRUE
if that pin is high. Else will always return TRUE.
usb_enumerated()
Returns TRUE if the device has been enumerated by the PC. If the
device has been enumerated by the PC, that means it is in normal
operation mode and you can send/receive packets.
usb_put_packet
(endpoint, data, len,
tgl)
usb_puts
(endpoint, data, len,
timeout)
Places the packet of data into the specified endpoint buffer. Returns
TRUE if success, FALSE if the buffer is still full with the last packet.
usb_kbhit(endpoint)
Returns TRUE if the specified endpoint has data in it's receive buffer
80
Sends the following data to the specified endpoint. usb_puts() differs
from usb_put_packet() in that it will send multi packet messages if the
data will not fit into one packet.
Functional Overviews
usb_get_packet
(endpoint, ptr, max)
Reads up to max bytes from the specified endpoint buffer and saves it to
the pointer ptr. Returns the number of bytes saved to ptr.
usb_gets(endpoint,
ptr,
max, timeout)
Reads a message from the specified endpoint. The difference
usb_get_packet() and usb_gets() is that usb_gets() will wait until a full
message has received, which a message may contain more than one
packet. Returns the number of bytes received.
Relevant CDC Functions:
A CDC USB device will emulate an RS-232 device, and will appear on your PC as a COM port.
The follow functions provide you this virtual RS-232/serial interface
Note: When using the CDC library, you can use the same functions above, but do not use the
packet related function such as
usb_kbhit(), usb_get_packet(), etc.
usb_cdc_kbhit()
The same as kbhit(), returns TRUE if there is 1 or more character in the
receive buffer.
usb_cdc_getc()
The same as getc(), reads and returns a character from the receive
buffer. If there is no data in the receive buffer it will wait indefinitely until
there a character has been received.
usb_cdc_putc(c)
The same as putc(), sends a character. It actually puts a character into
the transmit buffer, and if the transmit buffer is full will wait indefinitely
until there is space for the character.
usb_cdc_putc_fast(c)
The same as usb_cdc_putc(), but will not wait indefinitely until there is
space for the character in the transmit buffer. In that situation the
character is lost.
usb_cdc_putready()
Returns TRUE if there is space in the transmit buffer for another
character.
Relevant Preporcessor:
None
Relevant Interrupts:
#int_usb
Relevant Include files:
pic_usb.h
A USB event has happened, and requires application intervention. The
USB library that CCS provides handles this interrupt automatically.
Hardware layer driver for the PIC16C765 family PICmicro controllers
with an internal USB peripheral.
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C Compiler Reference Manual August 2009
pic_18usb.h
Hardware layer driver for the PIC18F4550 family PICmicro controllers
with an internal USB peripheral.
usbn960x.h
Hardware layer driver for the National USBN9603/USBN9604 external
USB peripheral. You can use this external peripheral to add USB to any
microcontroller.
usb.h
Common definitions and prototypes used by the USB driver
usb.c
The USB stack, which handles the USB interrupt and USB Setup
Requests on Endpoint 0.
usb_cdc.h
A driver that takes the previous include files to make a CDC USB device,
which emulates an RS232 legacy device and shows up as a COM port in
the MS Windows device manager.
Relevant getenv() Parameters:
USB
Returns TRUE if the PICmicro controller has an integrated internal USB
peripheral.
Example Code:
Due to the complexity of USB example code will not fit here. But you can find the following
examples installed with your CCS C Compiler:
ex_usb_hid.c
ex_usb_mouse.c
A simple HID device
A HID Mouse, when connected to your PC the mouse cursor will go in
circles.
ex_usb_kbmouse.c
An example of how to create a USB device with multiple interfaces by
creating a keyboard and mouse in one device.
ex_usb_kbmouse2.c
An example of how to use multiple HID report Ids to transmit more than
one type of HID packet, as demonstrated by a keyboard and mouse on
one device.
ex_usb_scope.c
A vendor-specific class using bulk transfers is demonstrated.
ex_usb_serial.c
The CDC virtual RS232 library is demonstrated with this RS232 < - >
USB example.
ex_usb_serial2.c
Another CDC virtual RS232 library example, this time a port of the
ex_intee.c example to use USB instead of RS232.
82
Functional Overviews
Voltage Reference
These functions configure the voltage reference module. These are available only in the supported chips.
Relevant Functions:
setup_vref(mode| value)
Enables and sets up the internal voltage reference
value.
Constants are defined in the devices .h file.
Relevant Preprocessor:
None
Relevant Interrupts:
None
Relevant Include Files:
None, all functions built-in
Relevant getenv() parameters:
VREF
Returns 1 if the device has VREF
Example Code:
For eg:
For PIC12F675
#INT_COMP //comparator interrupt handler
void isr() {
safe_conditions=FALSE;
printf("WARNING!! Voltage level is above 3.6 V. \r\n");
}
setup_comparator(A1_VR_OUT_ON_A2);
// sets two comparators(A1 and VR and A2 as the
output)
setup_vref(VREF_HIGH|15);
//sets 3.6(vdd *value/32 +vdd/4) if vdd is 5.0V
enable_interrupts(INT_COMP);
//enables the comparator interrupt
enable_interrupts(GLOBAL);
//enables global interrupts
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WDT or Watch Dog Timer
Different chips provide different options to enable/disable or configure the WDT.
Relevant Functions:
Enables/disables the wdt or sets the prescalar.
setup_wdt
restart_wdt
Restarts the wdt, if wdt is enables this must be periodically called
to prevent a timeout reset.
For PCB/PCM chips it is enabled/disabled using WDT or NOWDT fuses whereas on PCH device it
is done using the setup_wdt function.
The timeout time for PCB/PCM chips are set using the setup_wdt function and on PCH using fuses
like WDT16, WDT256 etc.
RESTART_WDT when specified in #use delay , #use I2c and #use RS232 statements like this
#use delay(clock=20000000, restart_wdt) will cause the wdt to restart if it times out during the delay
or I2C_READ or GETC.
Relevant Preprocessor:
#fuses WDT/NOWDT
Enabled/Disables wdt in PCB/PCM devices
#fuses WDT16
Sets ups the timeout time in PCH devices
Relevant Interrupts:
None
Relevant Include Files:
None, all functions built-in
Relevant getenv() parameters:
None
Example Code:
For eg:
For PIC16F877
#fuses wdt
setup_wdt(WDT_2304MS);
while(true){
restart_wdt();
perform_activity();
}
For PIC18F452
#fuse WDT1
setup_wdt(WDT_ON);
while(true){
restart_wdt();
perform_activity();
}
Some of the PCB chips are share the WDT prescalar bits with timer0 so the WDT prescalar
constants can be used with setup_counters or setup_timer0 or setup_wdt functions.
84
PRE-PROCESSOR DIRECTIVES
PRE-PROCESSOR
Pre-processor directives all begin with a # and are followed by a specific command. Syntax is
dependent on the command. Many commands do not allow other syntactical elements on the
remainder of the line. A table of commands and a description is listed on the previous page.
Several of the pre-processor directives are extensions to standard C. C provides a pre-processor
directive that compilers will accept and ignore or act upon the following data. This implementation
will allow any pre-processor directives to begin with #PRAGMA. To be compatible with other
compilers, this may be used before non-standard features.
Examples:
Both of the following are valid
#INLINE
#PRAGMA INLINE
Standard C
Function
Qualifier
Pre-Defined
Identifier
RTOS
#IF expr
#IFDEF id
#IFNDEF
#ELSE
#ELIF
#DEFINE id string
#UNDEF id
#INCLUDE "FILENAME"
#WARNING
#ENDIF
#LIST
#NOLIST
#PRAGMA cmd
#ERROR
#INLINE
#SEPARATE
#INT_xxx
#INT_DEFAULT
#INT_GLOBAL
_ _DATE_ _
_ _DEVICE_ _
_ _FILE_ _
_ _LINE_ _
_ _FILENAME_ _
_ _TIME_ _
_ _PCH_ _
_ _PCM_ _
_ _PCB_ _
#TASK
#USE RTOS
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Device
Specification
Built-in
Libraries
Memory
Control
#DEVICE chip
#FUSES options
#SERIALIZE
#ID "filename"
#ID number
#HEXCOMMENT
#ID CHECKSUM
#USE DELAY
#USE FAST_IO
#USE SPI
#USE FIXED_IO
#USE I2C
#USE RS232
#USE STANDARD_IO
#ASM
#ENDASM
#ROM
#BIT id=id.const
#FILL_ROM
#TYPE
#BIT id=const.const
#LOCATE id=const
#ZERO_RAM
#BYTE id=const
#BYTE id=id
#ORG
#RESERVE
#WORD
#LINE
#CASE
#IMPORT
#PRIORITY
#EXPORT
#OPT
#OCS
#IGNORE_WARNINGS
#MODULE
#IMPORT
#EXPORT
#USE DYNAMIC_MEMORY
Compiler
Control
Linker
Capacitive
Touch Pad
86
#USE TOUCHPAD
#BUILD
Pre-Processor Directives
#ASM
#ENDASM
Syntax:
#asm
or
#asm ASIS
code
#endasm
Elements:
code is a list of assembly language instructions
Purpose:
The lines between the #ASM and #ENDASM are treated as assembly code to
be inserted. These may be
used anywhere an expression is allowed. The syntax is described on the
following page. Function return
values are sent in W0 for 16-bit, and W0, w1 for 32 bit. Be aware that any C
code after the #ENDASM and
before the end of the function may corrupt the value.
If the second form is used with ASIS then the compiler will not do any
optimization on the assembly. The
assembly code is used as-is.
Examples:
int find_parity(int data){
int count;
#asm
MOV #0x08, W0
MOV W0, count
CLR W0
loop:
XOR.B data,W0
RRC data,W0
DEC count,F
BRA NZ, loop
MOV #0x01,W0
ADD count,F
MOV count, W0
MOV W0, _RETURN_
#endasm
}
Example Files:
ex_glint.c
Also See:
None
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C Compiler Reference Manual August 2009
12 Bit and 14 Bit
ADDWF f,d
ANDWF f,d
CLRF f
CLRW
COMF f,d
DECF f,d
DECFSZ f,d
INCF f,d
INCFSZ f,d
IORWF f,d
MOVF f,d
MOVPHW
MOVPLW
MOVWF f
NOP
RLF f,d
RRF f,d
SUBWF f,d
SWAPF f,d
XORWF f,d
BCF f,b
BSF f,b
BTFSC f,b
BTFSS f,b
ANDLW k
CALL k
CLRWDT
GOTO k
IORLW k
MOVLW k
RETLW k
SLEEP
XORLW
OPTION
TRIS k
14 Bit
ADDLW k
SUBLW k
RETFIE
RETURN
f
d
f,b
k
may be a constant (file number) or a simple variable
may be a constant (0 or 1) or W or F
may be a file (as above) and a constant (0-7) or it may be just a bit variable reference.
may be a constant expression
Note that all expressions and comments are in C like syntax.
88
Pre-Processor Directives
PIC 18
ADDWF
CLRF
CPFSGT
DECFSZ
INFSNZ
MOVFF
f,d
f
f
f,d
f,d
fs,d
ADDWFC
COMF
CPFSLT
DCFSNZ
IORWF
MOVWF
f,d
f,d
f
f,d
f,d
f
ANDWF
CPFSEQ
DECF
INCF
MOVF
MULWF
f,d
f
f,d
f,d
f,d
f
NEGF
RRCF
SUBFWB
SWAPF
BCF
BTFSS
BN
BNOV
BRA
CLRWDT
NOP
PUSH
RETFIE
SLEEP
IORLW
MOVLW
SUBLW
TBLRD
TBLWT
TBLWT
f
f,d
f,d
f,d
f,b
f,b
n
n
n
s
k
k
k
*+
*
+*
RLCF
RRNCF
SUBWF
TSTFSZ
BSF
BTG
BNC
BNZ
BZ
DAW
NOP
RCALL
RETLW
ADDLW
LFSR
MULLW
XORLW
TBLRD
TBLWT
f,d
f,d
f,d
f
f,b
f,d
n
n
n
n
k
k
f,k
k
k
**+
RLNCF
SETF
SUBWFB
XORWF
BTFSC
BC
BNN
BOV
CALL
GOTO
POP
RESET
RETURN
ANDLW
MOVLB
RETLW
TBLRD
TBLRD
TBLWT
f,d
f
f,d
f,d
f,b
n
n
n
n,s
n
s
k
k
k
*
+*
*-
The compiler will set the access bit depending on the value of the file register.
If there is just a variable identifier in the #asm block then the compiler inserts an & before it. And if
it is an expression it must be a valid C expression that evaluates to a constant (no & here). In C an
un-subscripted array name is a pointer and a constant (no need for &).
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#BIT
Syntax:
#bit id = x.y
Elements:
id is a valid C identifier,
x is a constant or a C variable,
y is a constant 0-7
Purpose:
A new C variable (one bit) is created and is placed in memory at byte x and bit
y. This is useful to gain access in C directly to a bit in the processors special
function register map. It may also be used to easily access a bit of a standard
C variable.
Examples:
#bit T0IF = 0xb.2
...
TSBS:1IF = 0; // Clear Timer 0 interrupt flag
int result;
#bit result_odd = result.0
...
if (result_odd)
Example Files:
ex_glint.c
Also See:
#byte, #reserve, #locate, #word
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Pre-Processor Directives
#BUILD
Syntax:
#build(segment = address)
#build(segment = address, segment = address)
#build(segment = start:end)
#build(segment = start: end, segment = start: end)
#build(nosleep)
Elements:
segment is one of the following memory segments which may be assigned a
location: MEMORY, RESET, or INTERRUPT
address is a ROM location memory address. Start and end are used to
specify a range in memory to be used.
Start is the first ROM location and end is the last ROM location to be used.
Nosleep is used to prevent the compiler from inserting a sleep at the end of
main()
Purpose:
PIC18XXX devices with external ROM or PIC18XXX devices with no internal
ROM can direct the compiler to utilize the ROM. When linking multiple
compilation units, this directive must appear exactly the same in each
compilation unit.
Examples:
#build(memory=0x20000:0x2FFFF)
//Assigns memory space
#build(reset=0x200,interrupt=0x208) //Assigns start
//location
//of reset and
//interrupt
//vectors
#build(reset=0x200:0x207, interrupt=0x208:0x2ff)
//Assign limited space
//for reset and
//interrupt vectors.
#build(memory=0x20000:0x2FFFF)
//Assigns memory space
Example Files:
None
Also See:
#locate, #reserve, #rom, #org
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#BYTE
Syntax:
#byte id = x
Elements:
id is a valid C identifier,
x is a C variable or a constant
Purpose:
If the id is already known as a C variable then this will locate the variable at
address x. In this case the variable type does not change from the original
definition. If the id is not known a new C variable is created and placed at
address x with the type int (8 bit)
Warning: In both cases memory at x is not exclusive to this variable. Other
variables may be located at the same location. In fact when x is a variable,
then id and x share the same memory location.
Examples:
#byte
#byte
status = 3
b_port = 6
struct {
short int r_w;
short int c_d;
int unused : 2;
int data
: 4; } a_port;
#byte a_port = 5
...
a_port.c_d = 1;
Example Files:
ex_glint.c
Also See:
#bit, #locate, #reserve, #word
92
Pre-Processor Directives
#CASE
Syntax:
#case
Elements:
Purpose:
None
Will cause the compiler to be case sensitive. By default the compiler is case
insensitive. When linking multiple compilation units, this directive must appear
exactly the same in each compilation unit.
Warning: Not all the CCS example programs, headers and drivers have been
tested with case sensitivity turned on.
Examples:
#case
int STATUS;
void func() {
int status;
...
STATUS = status; // Copy local status to
//global
}
Example Files:
ex_cust.c
Also See:
None
_DATE_
Syntax:
__DATE__
Elements:
Purpose:
None
This pre-processor identifier is replaced at compile time with the date of the
compile in the form: "31-JAN-03"
Examples:
printf("Software was compiled on ");
printf(__DATE__);
Example Files:
Also See:
None
None
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C Compiler Reference Manual August 2009
#DEFINE
Syntax:
#define id text
or
#define id(x,y...) text
Elements:
id is a preprocessor identifier, text is any text, x,y and so on are local
preprocessor identifiers, and in this form there may be one or more identifiers
separated by commas.
Purpose:
Used to provide a simple string replacement of the ID with the given text from
this point of the program and on.
In the second form (a C macro) the local identifiers are matched up with similar
identifiers in the text and they are replaced with text passed to the macro where
it is used.
If the text contains a string of the form #idx then the result upon evaluation will
be the parameter id concatenated with the string x.
If the text contains a string of the form #idx#idy then parameter idx is
concatenated with parameter idy forming a new identifier.
Examples:
#define BITS 8
a=a+BITS;
//same as
a=a+8;
#define hi(x) (x<<4)
a=hi(a);
//same as
a=(a<<4);
Example Files:
ex_stwt.c, ex_macro.c
Also See:
#undef, #ifdef, #ifndef
94
Pre-Processor Directives
#DEVICE
Syntax:
#device chip options
#device Compilation mode selection
Elements:
Chip Optionschip is the name of a specific processor (like: PIC16C74), To get a current list
of supported devices:
START | RUN | CCSC +Q
Options are qualifiers to the standard operation of the device. Valid options are:
*=5
Use 5 bit pointers (for all parts)
*=8
Use 8 bit pointers (14 and 16 bit parts)
*=16
Use 16 bit pointers (for 14 bit parts)
ADC=x
Where x is the number of bits read_adc()
should return.
ICD=TRUE
Generates code compatible with Microchips
ICD debugging hardware.
WRITE_EEPROM=ASYNC
Prevents WRITE_EEPROM from hanging
while writing is taking place. When used, do
not write to EEPROM from both ISR and
outside ISR.
WRITE_EEPROM = NOINT
Allows interrupts to occur while the
write_eeprom() operations is polling the done bit
to check if the write operations has completed.
Can be used as long as no EEPROM operations
are performed during an ISR.
HIGH_INTS=TRUE
Use this option for high/low priority interrupts
on the PIC®18.
%f=.
No 0 before a decimal pint on %f numbers
less than 1.
OVERLOAD=KEYWORD
Overloading of functions is now supported.
Requires the use of the keyword for overloading.
OVERLOAD=AUTO
Default mode for overloading.
PASS_STRINGS=IN_RAM
A new way to pass constant strings to a
function by first copying the string to RAM
and then passing a pointer to RAM to the
function.
CONST=READ_ONLY
Uses the ANSI keyword CONST definition,
making CONST variables read only, rather
than located in program memory.
CONST=ROM
Uses the CCS compiler traditional keyword CONST
definition, making CONST variables located in
program memory. This is the default mode.
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Both chip and options are optional, so multiple #device lines may be used to
fully define the device. Be warned that a #device with a chip identifier, will clear
all previous #device and #fuse settings.
Compilation mode selectionThe #device directive supports compilation mode selection. The valid keywords are
CCS2, CCS3, CCS4 and ANSI. The default mode is CCS4. For the CCS4 and
ANSI mode, the compiler uses the default fuse settings NOLVP, PUT for chips with
these fuses. The NOWDT fuse is default if no call is made to restart_wdt().
Purpose:
CCS4
This is the default compilation mode. The pointer size in this mode
for PCM and PCH is set to *=16 if the part has RAM over 0FF.
ANSI
Default data type is SIGNED all other modes default is UNSIGNED.
Compilation is case sensitive, all other modes are case insensitive.
Pointer size is set to *=16 if the part has RAM over 0FF.
CCS2
CCS3
var16 = NegConst8 is compiled as: var16 = NegConst8 & 0xff
(no sign extension)Pointer size is set to *=8 for PCM and PCH
and *=5 for PCB. The overload keyword is required.
CCS2
only
The default #device ADC is set to the resolution of the part, all
other modes default to 8.
onebit = eightbits is compiled as onebit = (eightbits != 0)
All other modes compile as: onebit = (eightbits & 1)
Chip Options -Defines the target processor. Every program must have exactly
one #device with a chip. When linking multiple compilation units, this directive
must appear exactly the same in each compilation unit.
Compilation mode selection - The compilation mode selection allows existing
code to be compiled without encountering errors created by compiler
compliance. As CCS discovers discrepancies in the way expressions are
evaluated according to ANSI, the change will generally be made only to the
ANSI mode and the next major CCS release.
Examples:
Chip Options#device PIC16C74
#device PIC16C67 *=16
#device *=16 ICD=TRUE
#device PIC16F877 *=16 ADC=10
#device %f=.
printf("%f",.5); //will print .5, without the directive it
will print 0.5
Compilation mode selection#device CCS2
// This will set the ADC to the resolution of the part
Example Files:
ex_mxram.c, ex_icd.c, 16c74.h,
Also See:
read_adc()
96
Pre-Processor Directives
_DEVICE_
Syntax:
__DEVICE__
Elements:
Purpose:
None
This pre-processor identifier is defined by the compiler with the base number of
the current device (from a #device). The base number is usually the number
after the C in the part number. For example the PIC16C622 has a base
number of 622.
Examples:
#if __device__==71
SETUP_ADC_PORTS( ALL_DIGITAL );
#endif
Example Files:
Also See:
None
#device
#ERROR
Syntax:
Elements:
#error text
#error / warning text
#error / information text
text is optional and may be any text
Purpose:
Forces the compiler to generate an error at the location this directive appears in
the file. The text may include macros that will be expanded for the display.
This may be used to see the macro expansion. The command may also be
used to alert the user to an invalid compile time situation.
Examples:
#if BUFFER_SIZE>16
#error Buffer size is too large
#endif
#error
Macro test: min(x,y)
Example Files:
ex_psp.c
Also See:
#warning
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C Compiler Reference Manual August 2009
#EXPORT (options)
Syntax:
#EXPORT (options)
Elements:
FILE=filname
The filename which will be generated upon compile. If not given, the filname will
be the name of the file you are compiling, with a .o or .hex extension (depending
on output format).
ONLY=symbol+symbol+.....+symbol
Only the listed symbols will be visible to modules that import or link this
relocatable object file. If neither ONLY or EXCEPT is used, all symbols are
exported.
EXCEPT=symbol+symbol+.....+symbol
All symbols except the listed symbols will be visible to modules that import or link
this relocatable object file. If neither ONLY or EXCEPT is used, all symbols are
exported.
RELOCATABLE
CCS relocatable object file format. Must be imported or linked before loading into
a PIC. This is the default format when the #EXPORT is used.
HEX
Intel HEX file format. Ready to be loaded into a PIC. This is the default format
when no #EXPORT is used.
RANGE=start:stop
Only addresses in this range are included in the hex file.
OFFSET=address
Hex file address starts at this address (0 by default)
ODD
Only odd bytes place in hex file.
EVEN
Only even bytes placed in hex file.
Purpose:
98
This directive will tell the compiler to either generate a relocatable object file or
a stand-alone HEX binary. A relocatable object file must be linked into your
application, while a stand-alone HEX binary can be programmed directly into
the PIC.
The command line compiler and the PCW IDE Project Manager can also be
used to compile/link/build modules and/or projects.
Multiple #EXPORT directives may be used to generate multiple hex files. this
may be used for 8722 like devices with external memory.
Pre-Processor Directives
Examples:
#EXPORT(RELOCATABLE, ONLY=TimerTask)
void TimerFunc1(void) { /* some code */ }
void TimerFunc2(void) { /* some code */ }
void TimerFunc3(void) { /* some code */ }
void TimerTask(void)
{
TimerFunc1();
TimerFunc2();
TimerFunc3();
}
/*
This source will be compiled into a relocatable object, but
the object this is being linked to can only see TimerTask()
*/
Example Files:
See Also:
None
#IMPORT, #MODULE, Invoking the Command Line Compiler, Linker Overview
__FILE__
Syntax:
Elements:
Purpose:
__FILE__
None
The pre-processor identifier is replaced at compile time with the file path and
the filename of the file being compiled.
Examples:
if(index>MAX_ENTRIES)
printf("Too many entries, source file: "
__FILE__ " at line " __LINE__ "\r\n");
Example Files:
assert.h
Also See:
_ _ line_ _
__FILENAME__
Syntax:
Elements:
Purpose:
__FILENAME__
None
The pre-processor identifier is replaced at compile time with the filename of the
file being compiled.
Examples:
if(index>MAX_ENTRIES)
printf("Too many entries, source file: "
__FILENAME__ " at line " __LINE__ "\r\n");
Example Files:
Also See:
None
_ _ line_ _
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C Compiler Reference Manual August 2009
#FILL_ROM
Syntax:
Elements:
Purpose:
Examples:
Example Files:
Also See:
#fill_rom value
value is a constant 16-bit value
This directive specifies the data to be used to fill unused ROM locations. When
linking multiple compilation units, this directive must appear exactly the same in
each compilation unit.
#fill_rom 0x36
None
#rom
#FUSES
Syntax:
Elements:
Purpose:
#fuses options
options vary depending on the device. A list of all valid options has been put at
the top of each devices .h file in a comment for reference. The PCW device edit
utility can modify a particular devices fuses. The PCW pull down menu VIEW |
Valid fuses will show all fuses with their descriptions.
Some common options are:
• LP, XT, HS, RC
• WDT, NOWDT
• PROTECT, NOPROTECT
• PUT, NOPUT (Power Up Timer)
• BROWNOUT, NOBROWNOUT
This directive defines what fuses should be set in the part when it is programmed.
This directive does not affect the compilation; however, the information is put in the
output files. If the fuses need to be in Parallax format, add a PAR option. SWAP has
the special function of swapping (from the Microchip standard) the high and low
BYTES of non-program data in the Hex file. This is required for some device
programmers.
Some processors allow different levels for certain fuses. To access these levels,
assign a value to the fuse. For example, on the 18F452, the fuse PROTECT=6
would place the value 6 into CONFIG5L, protecting code blocks 0 and 3.
When linking multiple compilation units be aware this directive applies to the final
object file. Later files in the import list may reverse settings in previous files.
To eliminate all fuses in the output files use:
#FUSES none
Examples:
Example Files:
Also See:
100
#fuses
ex_sqw.c
None
HS,NOWDT
Pre-Processor Directives
#HEXCOMMENT
Syntax:
#HEXCOMMENT text comment for the top of the hex file
#HEXCOMMENT\ text comment for the end of the hex file
Elements:
Purpose:
None
Puts a comment in the hex file
Some programmers (MPLAB in particular) do not like comments at the top of
the hex file.
Examples:
#HEXCOMMENT Version 3.1 – requires 20MHz crystal
Example Files:
Also See:
None
None
#ID
Syntax:
#ID number 16
#ID number, number, number, number
#ID "filename"
#ID CHECKSUM
Elements:
Number162 is a 16 bit number, number is a 4 bit number, filename is any valid
PC filename and checksum is a keyword.
Purpose:
This directive defines the ID word to be programmed into the part. This directive
does not affect the compilation but the information is put in the output file.
The first syntax will take a 16-bit number and put one nibble in each of the four
ID words in the traditional manner. The second syntax specifies the exact value
to be used in each of the four ID words.
When a filename is specified the ID is read from the file. The format must be
simple text with a CR/LF at the end. The keyword CHECKSUM indicates the
device checksum should be saved as the ID.
Examples:
#id
#id
#id
Example Files:
Also See:
ex_cust.c
None
0x1234
"serial.num"
CHECKSUM
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#IF exp
#ELSE
#ELIF
#ENDIF
Syntax:
#if expr
code
#elif expr //Optional, any number may be used
code
#else
//Optional
code
#endif
Elements:
expr is an expression with constants, standard operators and/or preprocessor
identifiers. Code is any standard c source code.
Purpose:
The pre-processor evaluates the constant expression and if it is non-zero will
process the lines up to the optional #ELSE or the #ENDIF.
Note: you may NOT use C variables in the #IF. Only preprocessor identifiers
created via #define can be used.
The preprocessor expression DEFINED(id) may be used to return 1 if the id is
defined and 0 if it is not.
== and != operators now accept a constant string as both operands. This
allows for compile time comparisons and can be used with GETENV() when it
returns a string result.
Examples:
#if MAX_VALUE > 255
long value;
#else
int value;
#endif
#if getenv(“DEVICE”)==”PIC16F877”
//do something special for the PIC16F877
#endif
Example Files:
ex_extee.c
Also See:
#ifdef, #ifndef, getenv()
102
Pre-Processor Directives
#IFDEF
#IFNDEF
#ELSE
#ELIF
Syntax:
#ifdef id
code
#elif
code
#else
code
#endif
#ifndef id
code
#elif
code
#else
code
#endif
Elements:
id is a preprocessor identifier, code is valid C source code.
Purpose:
This directive acts much like the #IF except that the preprocessor simply
checks to see if the specified ID is known to the preprocessor (created with a
#DEFINE). #IFDEF checks to see if defined and #IFNDEF checks to see if it is
not defined.
Examples:
#define debug
// Comment line out for no debug
...
#ifdef DEBUG
printf("debug point a");
#endif
Example Files:
ex_sqw.c
Also See:
#if
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#IGNORE_WARNINGS
Syntax:
#ignore_warnings ALL
#IGNORE_WARNINGS NONE
#IGNORE_WARNINGS warnings
Elements:
warnings is one or more warning numbers separated by commas
Purpose:
This function will suppress warning messages from the compiler. ALL indicates
no warning will be generated. NONE indicates all warnings will be generated.
If numbers are listed then those warnings are suppressed.
Examples:
#ignore_warnings 203
while(TRUE) {
#ignore_warnings NONE
Example Files:
Also See:
None
Warning messages
#IMPORT (options)
Syntax:
#Import (options)
Elements:
FILE=filname
The filename of the object you want to link with this compilation.
ONLY=symbol+symbol+.....+symbol
Only the listed symbols will imported from the specified relocatable object file.
If neither ONLY or EXCEPT is used, all symbols are imported.
EXCEPT=symbol+symbol+.....+symbol
The listed symbols will not be imported from the specified relocatable object
file. If neither ONLY or EXCEPT is used, all symbols are imported.
RELOCATABLE
CCS relocatable object file format. This is the default format when the
#IMPORT is used.
COFF
COFF file format from MPASM, C18 or C30.
HEX
Imported data is straight hex data.
104
Pre-Processor Directives
RANGE=start:stop
Only addresses in this range are read from the hex file.
LOCATION=id
The identifier is made a constant with the start address of the imported data.
SIZE=id
The identifier is made a constant with the size of the imported data.
Purpose:
This directive will tell the compiler to include (link) a relocatable object with this
unit during compilation. Normally all global symbols from the specified file will
be linked, but the EXCEPT and ONLY options can prevent certain symbols
from being linked.
The command line compiler and the PCW IDE Project Manager can also be
used to compile/link/build modules and/or projects.
Examples:
#IMPORT(FILE=timer.o, ONLY=TimerTask)
void main(void)
{
while(TRUE)
TimerTask();
}
/*
timer.o is linked with this compilation, but only TimerTask()
is visible in scope from this object.
*/
Example Files:
None
See Also:
#EXPORT, #MODULE, Invoking the Command Line Compiler, Linker Overview
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#INCLUDE
Syntax:
#include
or
#include "filename"
Elements:
filename is a valid PC filename. It may include normal drive and path
information. A file with the extension ".encrypted" is a valid PC file. The
standard compiler #include directive will accept files with this extension and
decrypt them as they are read. This allows include files to be distributed without
releasing the source code.
Purpose:
Text from the specified file is used at this point of the compilation. If a full path
is not specified the compiler will use the list of directories specified for the
project to search for the file. If the filename is in "" then the directory with the
main source file is searched first. If the filename is in <> then the directory with
the main source file is searched last.
Examples:
#include
<16C54.H>
#include
Example Files:
Also See:
ex_sqw.c
None
#INLINE
Syntax:
#inline
Elements:
Purpose:
None
Tells the compiler that the function immediately following the directive is to be
implemented INLINE. This will cause a duplicate copy of the code to be placed
everywhere the function is called. This is useful to save stack space and to
increase speed. Without this directive the compiler will decide when it is best to
make procedures INLINE.
Examples:
#inline
swapbyte(int &a, int &b) {
int t;
t=a;
a=b;
b=t;
}
Example Files:
Also See:
ex_cust.c
#separate
106
Pre-Processor Directives
#INT_xxxx
Syntax:
#INT_AD
Analog to digital conversion complete
#INT_ADOF
Analog to digital conversion timeout
#INT_BUSCOL
Bus collision
#INT_BUSCOL2
Bus collision 2 detected
#INT_BUTTON
Pushbutton
#INT_CANERR
An error has occurred in the CAN module
#INT_CANIRX
An invalid message has occurred on the CAN bus
#INT_CANRX0
CAN Receive buffer 0 has received a new message
#INT_CANRX1
CAN Receive buffer 1 has received a new message
#INT_CANTX0
CAN Transmit buffer 0 has completed transmission
#INT_CANTX1
CAN Transmit buffer 0 has completed transmission
#INT_CANTX2
CAN Transmit buffer 0 has completed transmission
#INT_CANWAKE
Bus Activity wake-up has occurred on the CAN bus
#INT_CCP1
Capture or Compare on unit 1
#INT_CCP2
Capture or Compare on unit 2
#INT_CCP3
Capture or Compare on unit 3
#INT_CCP4
Capture or Compare on unit 4
#INT_CCP5
Capture or Compare on unit 5
#INT_COMP
Comparator detect
#INT_COMP0
Comparator 0 detect
#INT_COMP1
Comparator 1 detect
#INT_COMP2
Comparator 2 detect
#INT_CR
Cryptographic activity complete
#INT_EEPROM
Write complete
#INT_ETH
Ethernet module interrupt
#INT_EXT
External interrupt
#INT_EXT1
External interrupt #1
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108
#INT_EXT2
External interrupt #2
#INT_EXT3
External interrupt #3
#INT_I2C
I2C interrupt (only on 14000)
#INT_IC1
Input Capture #1
#INT_IC2QEI
Input Capture 2 / QEI Interrupt
#IC3DR
Input Capture 3 / Direction Change Interrupt
#INT_LCD
LCD activity
#INT_LOWVOLT
Low voltage detected
#INT_LVD
Low voltage detected
#INT_OSC_FAIL
System oscillator failed
#INT_OSCF
System oscillator failed
#INT_PMP
Parallel Master Port interrupt
#INT_PSP
Parallel Slave Port data in
#INT_PWMTB
PWM Time Base
#INT_RA
Port A any change on A0_A5
#INT_RB
Port B any change on B4-B7
#INT_RC
Port C any change on C4-C7
#INT_RDA
RS232 receive data available
#INT_RDA0
RS232 receive data available in buffer 0
#INT_RDA1
RS232 receive data available in buffer 1
#INT_RDA2
RS232 receive data available in buffer 2
#INT_RTCC
Timer 0 (RTCC) overflow
#INT_SPP
Streaming Parallel Port Read/Write
#INT_SSP
SPI or I2C activity
#INT_SSP2
SPI or I2C activity for Port 2
#INT_TBE
RS232 transmit buffer empty
#INT_TBE0
RS232 transmit buffer 0 empty
#INT_TBE1
RS232 transmit buffer 1 empty
Pre-Processor Directives
#INT_TBE2
RS232 transmit buffer 2 empty
#INT_TIMER0
Timer 0 (RTCC) overflow
#INT_TIMER1
Timer 1 overflow
#INT_TIMER2
Timer 2 overflow
#INT_TIMER3
Timer 3 overflow
#INT_TIMER4
Timer 4 overflow
#INT_TIMER5
Timer 5 overflow
#INT_ULPWU
Ultra-low power wake up interrupt
#INT_USB
Universal Serial Bus activity
Note many more #INT_ options are available on specific chips. Check the
devices .h file for a full list for a given chip.
Elements:
None
Purpose:
These directives specify the following function is an interrupt function.
Interrupt functions may not have any parameters. Not all directives may be
used with all parts. See the devices .h file for all valid interrupts for the part
or in PCW use the pull down VIEW | Valid Ints
The compiler will generate code to jump to the function when the interrupt is
detected. It will generate code to save and restore the machine state, and
will clear the interrupt flag. To prevent the flag from being cleared add
NOCLEAR after the #INT_xxxx. The application program must call
ENABLE_INTERRUPTS(INT_xxxx) to initially activate the interrupt along with
the ENABLE_INTERRUPTS(GLOBAL) to enable interrupts.
The keywords HIGH and FAST may be used with the PCH compiler to mark
an interrupt as high priority. A high-priority interrupt can interrupt another
interrupt handler. An interrupt marked FAST is performed without saving or
restoring any registers. You should do as little as possible and save any
registers that need to be saved on your own. Interrupts marked HIGH can be
used normally.
See #DEVICE for information on building with high-priority interrupts.
A summary of the different kinds of PIC18 interrupts:
#INT_xxxx
Normal (low priority) interrupt. Compiler saves/restores key registers.
This interrupt will not interrupt any interrupt in progress.
#INT_xxxx FAST
High priority interrupt. Compiler DOES NOT save/restore key
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registers.
This interrupt will interrupt any normal interrupt in progress.
Only one is allowed in a program.
#INT_xxxx HIGH
High priority interrupt. Compiler saves/restores key registers.
This interrupt will interrupt any normal interrupt in progress.
#INT_GLOBAL
Compiler generates no interrupt code. User function is located
at address 8 for user interrupt handling.
Examples:
#int_ad
adc_handler() {
adc_active=FALSE;
}
#int_rtcc noclear
isr() {
...
}
Example Files:
See ex_sisr.c and ex_stwt.c for full example programs.
Also See:
enable_interrupts(), disable_interrupts(), #int_default, #int_global, #PRIORITY
#INT_DEFAULT
Syntax:
#int_default
Elements:
None
Purpose:
The function following #INT_DEFAULT will be called if an interrupt occurs due
to setting of INT_GLOBAL and INT_xxx while no #INT_XXX routine is defined.
This allows the user to omit #INT_XXX in situations where multiple interrupts
could be serviced by the same routine and inspect the particular interrupt flag of
interest inside the routine assigned #INT_DEFAULT.
Examples:
#int_default
default_isr() {
printf("Unexplained interrupt\r\n");
}
Example Files:
Also See:
None
#INT_xxxx, #INT_global
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Pre-Processor Directives
#INT_GLOBAL
Syntax:
#int_global
Elements:
Purpose:
None
This directive causes the following function to replace the compiler interrupt
dispatcher. The function is normally not required and should be used with great
caution. When used, the compiler does not generate start-up code or clean-up
code, and does not save the registers.
Examples:
#int_global
isr() {
// Will be located at location 4 for PIC16 chips.
#asm
bsf
isr_flag
retfie
#endasm
}
Example Files:
ex_glint.c
Also See:
#int_xxxx
__LINE__
Syntax:
__line__
Elements:
None
Purpose:
The pre-processor identifier is replaced at compile time with line number of the
file being compiled.
Examples:
if(index>MAX_ENTRIES)
printf("Too many entries, source file: "
__FILE__" at line " __LINE__ "\r\n");
Example Files:
assert.h
Also See:
_ _ file_ _
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#LIST
Syntax:
#list
Elements:
None
Purpose:
#List begins inserting or resumes inserting source lines into the .LST file after
a #NOLIST.
Examples:
#NOLIST
// Don't clutter up the list file
#include
#LIST
Example Files:
16c74.h
Also See:
#nolist
#LINE
Syntax:
#line number filename
Elements:
Number is non-negative decimal integer. File name is optional.
Purpose:
The C pre-processor informs the C Compiler of the location in your source code.
This code is simply used to change the value of _LINE_ and _FILE_ variables.
Examples:
1. void main(){
#line 10
should be reported.
//
specifies the line number that
// for the following line of input
2. #line 7 "hello.c" // line number in the source file
hello.c and it sets the line 7 as current line and hello.c as
current file
Example Files:
Also See:
112
None
None
Pre-Processor Directives
#LOCATE
Syntax:
#locate id=x
Elements:
id is a C variable,
x is a constant memory address
Purpose:
#LOCATE works like #BYTE however in addition it prevents C from using the area.
A special form of this directive may be used to locate all A functions local
variables starting at a fixed location.
Use: #locate Auto = address
This directive will place the indirected C variable at the requested address.
Examples:
// This will locate the float variable at 50-53
// and C will not use this memory for other
// variables automatically located.
float x;
#locate x=0x50
Example Files:
Also See:
ex_glint.c
#byte, #bit, #reserve, #word
#MODULE
Syntax:
#MODULE
Elements:
Purpose:
None
All global symbols created from the #MODULE to the end of the file will only be
visible within that same block of code (and files #included within that block).
This may be used to limit the scope of global variables and functions within
include files. This directive also applies to pre-processor #defines.
Note: The extern and static data qualifiers can also be used to denote scope of
variables and functions as in the standard C methodology. #MODULE does
add some benefits in that pre-processor #defines can be given scope, which
cannot normally be done in standard C methodology.
Examples:
int GetCount(void);
void SetCount(int newCount);
#MODULE
int g_count;
#define G_COUNT_MAX 100
int GetCount(void) {return(g_count);}
void SetCount(int newCount) {
if (newCount>G_COUNT_MAX)
newCount=G_COUNT_MAX;
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g_count=newCount;
}
/*
the functions GetCount() and SetCount() have global scope, but
the variable g_count and the #define G_COUNT_MAX only has
scope to this file.
*/
Example Files:
See Also:
None
#EXPORT, Invoking the Command Line Compiler, Linker Overview
#NOLIST
Syntax:
#nolist
Elements:
Purpose:
None
Stops inserting source lines into the .LST file (until a #LIST)
Examples:
#NOLIST
// Don't clutter up the list file
#include
#LIST
Example Files:
Also See:
16c74.h
#LIST
#OPT
Syntax:
#OPT n
Elements:
All Devices: n is the optimization level 0-9
PIC18XXX: n is the optimization level 0-11
Purpose:
The optimization level is set with this directive. This setting applies to the entire
program and may appear anywhere in the file. The PCW default is 9 for full
optimization. PIC18XXX devices may utilize levels 10 and 11 for extended
optimization. Level 9 may be used to set a PCW compile to look exactly like a
PCM compile for example. It may also be used if an optimization error is
suspected to reduce optimization.
Examples:
#opt 5
Example Files:
Also See:
None
None
114
Pre-Processor Directives
#ORG
Syntax:
#org start, end
or
#org segment
or
#org start, end {}
or
#org start, end auto=0
#ORG start,end DEFAULT
or
#ORG DEFAULT
Elements:
start is the first ROM location (word address) to use, end is the last ROM
location, segment is the start ROM location from a previous #org
Purpose:
This directive will fix the following function or constant declaration into a specific
ROM area. End may be omitted if a segment was previously defined if you only
want to add another function to the segment.
Follow the ORG with a {} to only reserve the area with nothing inserted by the
compiler.
The RAM for a ORG'ed function may be reset to low memory so the local
variables and scratch variables are placed in low memory. This should only be
used if the ORG'ed function will not return to the caller. The RAM used will
overlap the RAM of the main program. Add a AUTO=0 at the end of the #ORG
line.
If the keyword DEFAULT is used then this address range is used for all
functions user and compiler generated from this point in the file until a #ORG
DEFAULT is encountered (no address range). If a compiler function is called
from the generated code while DEFAULT is in effect the compiler generates a
new version of the function within the specified address range.
When linking multiple compilation units be aware this directive applies to the
final object file. It is an error if any #org overlaps between files unless the #org
matches exactly.
Examples:
#ORG 0x1E00, 0x1FFF
MyFunc() {
//This function located at 1E00
}
#ORG 0x1E00
Anotherfunc(){
// This will be somewhere 1E00-1F00
}
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#ORG 0x800, 0x820 {}
//Nothing will be at 800-820
#ORG 0x1C00, 0x1C0F
CHAR CONST ID[10}= {"123456789"};
//This ID will be at 1C00
//Note some extra code will
//proceed the 123456789
#ORG 0x1F00, 0x1FF0
Void loader (){
.
.
.
}
Example Files:
loader.c
Also See:
#ROM
#OCS
Syntax:
#OCS x
Elements:
x is the clock's speed and can be 1 Hz to 100 MHz.
Purpose:
Used instead of the #use delay(clock = x)
Examples:
#include <18F4520.h>
#device ICD=TRUE
#OCS 20 MHz
#use rs232(debugger)
void main(){
-------;
}
Example Files:
Also See:
116
None
#use delay
Pre-Processor Directives
__PCB__
Syntax:
__PCB__
Elements:
None
Purpose:
The PCB compiler defines this pre-processor identifier. It may be used to
determine if the PCB compiler is doing the compilation.
Examples:
#ifdef __pcb__
#device PIC16c54
#endif
Example Files:
ex_sqw.c
Also See:
__PCM__, __PCH__
__ PCM __
Syntax:
__PCM__
Elements:
Purpose:
None
The PCM compiler defines this pre-processor identifier. It may be used to
determine if the PCM compiler is doing the compilation.
Examples:
#ifdef __pcm__
#device PIC16c71
#endif
Example Files:
ex_sqw.c
Also See:
__PCB__, __PCH__
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__ PCH __
Syntax:
__PCH__
Elements:
Purpose:
None
The PCH compiler defines this pre-processor identifier. It may be used to
determine if the PCH compiler is doing the compilation.
Examples:
#ifdef _ _ PCH _ _
#device PIC18C452
#endif
Example Files:
ex_sqw.c
Also See:
__PCB__, __PCM__
#PIN_SELECT
Syntax:
#pin_select function=pin_xx
Elements:
function is the Microchip defined pin function name, such as: U1RX (UART1
receive), INT1 (external interrupt 1), T2CK (timer 2 clock), IC1 (input capture 1),
OC1 (output capture 1) For a full list of valid pin function names, refer the
datasheet for your target PIC microcontroller.
pin_xx is the CCS provided pin definition. For example: PIN_C7, PIN_B0,
PIN_D3, etc.
Purpose:
When using PPS chips a #pin_select must be appear before these peripherals
can be used or referenced.
Examples:
#pin_select U1TX=PIN_C6
#pin_select U1RX=PIN_C7
#pin_select INT1=PIN_B0
Example Files:
None
Also See:
None
118
Pre-Processor Directives
#PRAGMA
Syntax:
#pragma cmd
Elements:
cmd is any valid preprocessor directive.
Purpose:
This directive is used to maintain compatibility between C compilers. This
compiler will accept this directive before any other pre-processor command. In
no case does this compiler require this directive.
Examples:
#pragma device
Example Files:
ex_cust.c
Also See:
None
PIC16C54
#PRIORITY
Syntax:
#priority ints
Elements:
ints is a list of one or more interrupts separated by commas.
export makes the functions generated from this directive available to other
compilation units within the link.
Purpose:
The priority directive may be used to set the interrupt priority. The highest
priority items are first in the list. If an interrupt is active it is never interrupted. If
two interrupts occur at around the same time then the higher one in this list will
be serviced first. When linking multiple compilation units be aware only the one
in the last compilation unit is used.
Examples:
#priority rtcc,rb
Example Files:
Also See:
None
#int_xxxx
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#RESERVE
Syntax:
#reserve address
or
#reserve address, address, address
or
#reserve start:end
Elements:
address is a RAM address, start is the first address and end is the last address
Purpose:
This directive allows RAM locations to be reserved from use by the compiler.
#RESERVE must appear after the #DEVICE otherwise it will have no effect.
When linking multiple compilation units be aware this directive applies to the
final object file.
Examples:
#DEVICE PIC16C74
#RESERVE 0x60:0X6f
Example Files:
ex_cust.c
Also See:
#org
#ROM
Syntax:
#rom address = {list}
#rom int8 address = {list}
#rom char address = {list}
Elements:
address is a ROM word address, list is a list of words separated by commas
Purpose:
Allows the insertion of data into the .HEX file. In particular, this may be used to
program the '84 data EEPROM, as shown in the following example.
Note that if the #ROM address is inside the program memory space, the
directive creates a segment for the data, resulting in an error if a #ORG is over
the same area. The #ROM data will also be counted as used program memory
space.
The int8 option indicates each item is 8 bits, the default is 16 bits.
The char option treats each item as 7 bits packing 2 chars into every pcm 14-bit word.
When linking multiple compilation units be aware this directive applies to the
final object file.
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Pre-Processor Directives
Some special forms of this directive may be used for verifying program
memory:
#rom address = checksum
This will put a value at address such that the entire program memory will
sum to 0x1248
#rom address = crc16
This will put a value at address that is a crc16 of all the program memory
except the specified address
#rom address = crc8
This will put a value at address that is a crc16 of all the program memory
except the specified address
Examples:
#rom
Example Files:
None
Also See:
#org
0x2100={1,2,3,4,5,6,7,8}
#SEPARATE
Syntax:
#separate
Elements:
Purpose:
None
Tells the compiler that the procedure IMMEDIATELY following the directive is to be
implemented SEPARATELY. This is useful to prevent the compiler from
automatically making a procedure INLINE. This will save ROM space but it does
use more stack space. The compiler will make all procedures marked SEPARATE,
separate, as requested, even if there is not enough stack space to execute.
Examples:
#separate
swapbyte (int *a, int *b) {
int t;
t=*a;
*a=*b;
*b=t;
}
Example Files:
ex_cust.c
Also See:
#inline
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#SERIALIZE
Syntax:
#serialize(id=xxx, next="x" | file="filename.txt" " | listfile="filename.txt",
"prompt="text", log="filename.txt") Or-#serialize(dataee=x, binary=x, next="x" | file="filename.txt" |
listfile="filename.txt", prompt="text", log="filename.txt")
Elements:
id=xxx - Specify a C CONST identifier, may be int8, int16, int32 or char array
Use in place of id parameter, when storing serial number to EEPROM:
dataee=x - The address x is the start address in the data EEPROM.
binary=x - The integer x is the number of bytes to be written to address
specified. -orstring=x - The integer x is the number of bytes to be written to address
specified.
Use only one of the next three options:
file="filename.txt" - The file x is used to read the initial serial number from,
and this file is updated by the ICD programmer. It is assumed this is a one line
file with the serial number. The programmer will increment the serial number.
listfile="filename.txt" - The file x is used to read the initial serial number from,
and this file is updated by the ICD programmer. It is assumed this is a file one
serial number per line. The programmer will read the first line then delete that
line from the file.
next="x" - The serial number X is used for the first load, then the hex file is
updated to increment x by one.
Other optional parameters:
prompt="text" - If specified the user will be prompted for a serial number on
each load. If used with one of the above three options then the default value
the user may use is picked according to the above rules.
log=xxx - A file may optionally be specified to keep a log of the date, time, hex
file name and serial number each time the part is programmed. If no id=xxx is
specified then this may be used as a simple log of all loads of the hex file.
Purpose:
Assists in making serial numbers easier to implement when working with CCS
ICD units. Comments are inserted into the hex file that the ICD software
interprets.
Examples:
//Prompt user for serial number to be placed
//at address of serialNumA
//Default serial number = 200int8 const serialNumA=100;
#serialize(id=serialNumA,next="200",prompt="Enter the serial
number")
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//Adds serial number log in seriallog.txt
#serialize(id=serialNumA,next="200",prompt="Enter the serial
number", log="seriallog.txt")
//Retrieves serial number from serials.txt
#serialize(id=serialNumA,listfile="serials.txt")
//Place serial number at EEPROM address 0, reserving 1 byte
#serialize(dataee=0,binary=1,next="45",prompt="Put in Serial
number")
//Place string serial number at EEPROM address 0, reserving 2
bytes
#serialize(dataee=0, string=2,next="AB",prompt="Put in Serial
number")
Example Files:
None
Also See:
None
#TASK
(The RTOS is only included with the PCW and PCWH packages.)
Each RTOS task is specified as a function that has no parameters and no return. The #task
directive is needed just before each RTOS task to enable the compiler to tell which functions are
RTOS tasks. An RTOS task cannot be called directly like a regular function can.
Syntax:
#task (options)
Elements:
options are separated by comma and may be:
rate=time
Where time is a number followed by s, ms, us, or ns. This specifies how often the
task will execute.
max=time
Where time is a number followed by s, ms, us, or ns. This specifies the budgeted
time for this task.
queue=bytes
Specifies how many bytes to allocate for this task's incoming messages. The default
value is 0.
Purpose:
This directive tells the compiler that the following function is an RTOS task.
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The rate option is used to specify how often the task should execute. This must be a
multiple of the minor_cycle option if one is specified in the #use rtos directive.
The max option is used to specify how much processor time a task will use in one
execution of the task. The time specified in max must be equal to or less than the
time specified in the minor_cycle option of the #use rtos directive before the project
will compile successfully. The compiler does not have a way to enforce this limit on
processor time, so a programmer must be careful with how much processor time a
task uses for execution. This option does not need to be specified.
The queue option is used to specify the number of bytes to be reserved
for the task to receive messages from other tasks or functions. The default queue
value is 0.
Examples:
#task(rate=1s, max=20ms, queue=5)
Also See:
#use rtos
__ TIME __
Syntax:
__TIME__
Elements:
Purpose:
None
This pre-processor identifier is replaced at compile time with the time of the
compile in the form: "hh:mm:ss"
Examples:
printf("Software was compiled on ");
printf(__TIME__);
Example Files:
Also See:
None
None
#TYPE
Syntax:
#type standard-type=size
#type default=area
#type unsigned
#type signed
Elements:
standard-type is one of the C keywords short, int, long, or default
size is 1,8,16, or 32
area is a memory region defined before the #TYPE using the addressmod
directive
Purpose:
By default the compiler treats SHORT as one bit, INT as 8 bits, and LONG as
16 bits. The traditional C convention is to have INT defined as the most efficient
124
Pre-Processor Directives
size for the target processor. This is why it is 8 bits on the PIC®. In order to
help with code compatibility a #TYPE directive may be used to allow these
types to be changed. #TYPE can redefine these keywords.
Note that the commas are optional. Since #TYPE may render some sizes
inaccessible (like a one bit int in the above) four keywords representing the four
ints may always be used: INT1, INT8, INT16, and INT32. Be warned CCS
example programs and include files may not work right if you use #TYPE in
your program.
This directive may also be used to change the default RAM area used for
variable storage. This is done by specifying default=area where area is a
addressmod address space.
When linking multiple compilation units be aware this directive only applies to
the current compilation unit.
The #TYPE directive allows the keywords UNSIGNED and SIGNED to set the
default data type.
Examples:
#TYPE
SHORT=8, INT=16, LONG=32
#TYPE default=area
addressmod (user_ram_block, 0x100, 0x1FF);
#type default=user_ram_block // all variable declarations
// in this area will be in
// 0x100-0x1FF
#type default=
// back to normal
// restores memory allocation
#TYPE SIGNED
...
void main()
{
int variable1;
127
...
...
}
Example Files:
ex_cust.c
Also See:
None
// variable1 can only take values from -128 to
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#UNDEF
Syntax:
#undef id
Elements:
id is a pre-processor id defined via #define
Purpose:
The specified pre-processor ID will no longer have meaning to the pre-processor.
Examples:
#if MAXSIZE<100
#undef MAXSIZE
#define MAXSIZE 100
#endif
Example Files:
None
Also See:
#define
#USE DELAY
Syntax:
Elements:
#use delay (clock=speed)
#use delay (clock=speed, restart_wdt)
#use delay (clock=speed, type)
#use delay (clock=speed, type=speed)
#use delay (type=speed)
speed is a constant 1-100000000 (1 hz to 100 mhz). This number can contains
commas. This number also supports the following denominations: M, MHZ, K, KHZ
type defines what kind of clock you are using, and the following values are valid:
oscillator, osc (same as oscillator), crystal, xtal (same as crystal), internal, int (same
as internal) or rc. The compiler will automatically set the oscillator configuration bits
based upon your defined type. If you specified internal, the compiler will also
automatically set the internal oscillator to the defined speed.
Purpose:
restart_wdt will restart the watchdog timer on every delay_us() and delay_ms() use.
Tells the compiler the speed of the processor and enables the use of the built-in
functions: delay_ms() and delay_us(). Will also set the proper configuration bits, and
if needed configure the internal oscillator. Speed is in cycles per second. An
optional restart_WDT may be used to cause the compiler to restart the WDT while
delaying. When linking multiple compilation units, this directive must appear in any
unit that needs timing configured (delay_ms(), delay_us(), UART, SPI).
In multiple clock speed applications, this directive may be used more than once. Any
timing routines (delay_ms(), delay_us, UART, SPI) that need timing information will
use the last defined #use delay(). For initialization purposes, the compiler will initialize
the configuration bits and internal oscillator based upon the first #use delay().
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Pre-Processor Directives
Examples:
//set timing config to 32KHz, restart watchdog timer
//on delay_us() and delay_ms()
#use delay (clock=32000, RESTART_WDT)
//the following 4 examples all configure the timing library
//to use a 20Mhz clock, where the source is an oscillator.
#use delay (clock=20000000)
//user must manually set HS config bit
#use delay (clock=20,000,000) //user must manually set HS config bit
#use delay(clock=20M)
//user must manually set HS config bit
#use delay(clock=20M, oscillator)//compiler will set HS config bit
#use delay(oscillator=20M)
//compiler will set HS config bit
//application is using a 10Mhz oscillator, but using the 4x PLL
//to upscale it to 40Mhz. Compiler will set H4 config bit.
#use delay(clock=40M, oscillator=10M)
//application will use the internal oscillator at 8MHz.
//compiler will set INTOSC_IO config bit, and set the internal
//oscillator to 8MHz.
#use delay(internal=8M)
Example Files: ex_sqw.c
Also See:
delay_ms(), delay_us()
#USE DYNAMIC_MEMORY
Syntax:
#USE DYNAMIC_MEMORY
Elements:
None
Purpose:
This pre-processor directive instructs the compiler to create the
_DYNAMIC_HEAD object. _DYNAMIC_HEAD is the location where the first
free space is allocated.
Examples:
#USE DYNAMIC_MEMORY
void main ( ){
}
Example Files:
EX_MALLOC.C
Also See:
None
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#USE FAST_IO
Syntax:
#use fast_io (port)
Elements:
port is A, B, C, D, E, F, G, H, J or ALL
Purpose:
Affects how the compiler will generate code for input and output instructions
that follow. This directive takes effect until another #use xxxx_IO directive is
encountered. The fast method of doing I/O will cause the compiler to perform
I/O without programming of the direction register. The compiler's default
operation is the opposite of this command, the direction I/O will be set/cleared
on each I/O operation. The user must ensure the direction register is set
correctly via set_tris_X(). When linking multiple compilation units be aware this
directive only applies to the current compilation unit.
Examples:
#use fast_io(A)
Example Files:
ex_cust.c
Also See:
#use fixed_io, #use standard_io, set_tris_X() , General Purpose I/O
#USE FIXED_IO
Syntax:
#use fixed_io (port_outputs=pin, pin?)
Elements:
port is A-G, pin is one of the pin constants defined in the devices .h file.
Purpose:
This directive affects how the compiler will generate code for input and output
instructions that follow. This directive takes effect until another #use xxx_IO
directive is encountered. The fixed method of doing I/O will cause the compiler
to generate code to make an I/O pin either input or output every time it is used.
The pins are programmed according to the information in this directive (not the
operations actually performed). This saves a byte of RAM used in standard I/O.
When linking multiple compilation units be aware this directive only applies to
the current compilation unit.
Examples:
#use fixed_io(a_outputs=PIN_A2, PIN_A3)
Example Files:
None
Also See:
#use fast_io, #use standard_io, General Purpose I/O
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Pre-Processor Directives
#USE I2C
Syntax:
#use i2c (options)
Elements:
Options are separated by commas and may be:
MASTER
Sets to the master mode
MULTI_MASTER
Set the multi_master mode
SLAVE
Set the slave mode
SCL=pin
Specifies the SCL pin (pin is a bit address)
SDA=pin
Specifies the SDA pin
ADDRESS=nn
Specifies the slave mode address
FAST
Use the fast I2C specification.
FAST=nnnnnn
Sets the speed to nnnnnn hz
SLOW
Use the slow I2C specification
RESTART_WDT
Restart the WDT while waiting in I2C_READ
FORCE_HW
Use hardware I2C functions.
FORCE_SW
Use software I2C functions.
NOFLOAT_HIGH
Does not allow signals to float high, signals are driven from
low to high
SMBUS
Bus used is not I2C bus, but very similar
STREAM=id
Associates a stream identifier with this I2C port. The
identifier may then be used in functions like i2c_read or
i2c_write.
NO_STRETCH
Do not allow clock streaching
MASK=nn
Set an address mask for parts that support it
I2C1
Instead of SCL= and SDA= this sets the pins to the first
module
I2C2
Instead of SCL= and SDA= this sets the pins to the second
module
Only some chips allow the following:
DATA_HOLD
No ACK is sent until I2C_READ is called for data bytes
(slave only)
ADDRESS_HOLD
No ACK is sent until I2C_read is called for the address
byte (slave only)
SDA_HOLD
Min of 300ns holdtime on SDA a from SCL goes low
Purpose:
The I2C library contains functions to implement an I2C bus. The #USE I2C remains
in effect for the I2C_START, I2C_STOP, I2C_READ, I2C_WRITE and I2C_POLL
functions until another USE I2C is encountered. Software functions are generated
unless the FORCE_HW is specified. The SLAVE mode should only be used with the
built-in SSP. The functions created with this directive are exported when using
multiple compilation units. To access the correct function use the stream identifier.
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Examples:
#use I2C(master, sda=PIN_B0, scl=PIN_B1)
#use I2C(slave,sda=PIN_C4,scl=PIN_C3
address=0xa0,FORCE_HW)
#use I2C(master, scl=PIN_B0, sda=PIN_B1, fast=450000)
//sets the target speed to 450 KBSP
Example
Files:
Also See:
ex_extee.c with 16c74.h
i2c_read(), i2c_write()
#USE RS232
Syntax:
Elements:
#use rs232 (options)
Options are separated by commas and may be:
STREAM=id
Associates a stream identifier with this RS232 port.
The identifier may then be used in functions like fputc.
BAUD=x
Set baud rate to x
NOINIT option:
Use baud=0 to not init the UART and pins C6 and C7
can still be used for input-output functions.
#use rs232(baud=0,options)
To make printf work with NOINIT option, use:
setup_uart(9600);
130
XMIT=pin
Set transmit pin
RCV=pin
Set receive pin
FORCE_SW
Will generate software serial I/O routines even when
the UART pins are specified.
BRGH1OK
Allow bad baud rates on chips that have baud rate
problems.
ENABLE=pin
The specified pin will be high during transmit. This
may be used to enable 485 transmit.
Pre-Processor Directives
DEBUGGER
Indicates this stream is used to send/receive data
though a CCS ICD unit. The default pin used in B3,
use XMIT= and RCV= to change the pin used. Both
should be the same pin.
RESTART_WDT
Will cause GETC() to clear the WDT as it waits for a
character.
INVERT
PARITY=X
Invert the polarity of the serial pins (normally not
needed when level converter, such as the MAX232).
May not be used with the internal UART.
Where x is N, E, or O.
BITS =X
Where x is 5-9 (5-7 may not be used with the SCI).
FLOAT_HIGH
The line is not driven high. This is used for open
collector outputs. Bit 6 in RS232_ERRORS is set if
the pin is not high at the end of the bit time.
ERRORS
Used to cause the compiler to keep receive errors in
the variable RS232_ERRORS and to reset errors
when they occur.
SAMPLE_EARLY
A getc() normally samples data in the middle of a bit
time. This option causes the sample to be at the
start of a bit time. May not be used with the UART.
RETURN=pin
For FLOAT_HIGH and MULTI_MASTER this is the
pin used to read the signal back. The default for
FLOAT_HIGH is the XMIT pin and for
MULTI_MASTER the RCV pin.
MULTI_MASTER
Uses the RETURN pin to determine if another master
on the bus is transmitting at the same time. If a
collision is detected bit 6 is set in RS232_ERRORS
and all future PUTC's are ignored until bit 6 is cleared.
The signal is checked at the start and end of a bit
time. May not be used with the UART.
LONG_DATA
Makes getc() return an int16 and putc accept an
int16. This is for 9 bit data formats.
DISABLE_INTS
Will cause interrupts to be disabled when the routines
get or put a character. This prevents character distortion
for software implemented I/O and prevents interaction
between I/O in interrupt handlers and the main program
when using the UART.
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STOP=X
To set the number of stop bits (default is 1). This works
UART and non-UART ports.
TIMEOUT=X
To set the time getc() waits for a byte in
milliseconds. If no character comes in within this time
the RS232_ERRORS is set to 0 as well as the return
value form getc(). This works for both UART and
non-UART ports.
Makes the RS232 line a synchronous slave, making the
receive pin a clock in, and the data pin the data in/out.
SYNC_SLAVE
SYNC_MASTER
Makes the RS232 line a synchronous master,
making the receive pin a clock out, and the data pin
the data in/out.
SYNC_MATER_CONT
Makes the RS232 line a synchronous master mode in
continuous receive mode. The receive pin is set as a
clock out, and the data pin is set as the data in/out.
UART1
Sets the XMIT= and RCV= to the chips first
hardware UART.
UART2
Purpose:
Sets the XMIT= and RCV= to the chips second
hardware UART.
This directive tells the compiler the baud rate and pins used for serial I/O. This
directive takes effect until another RS232 directive is encountered. The #USE
DELAY directive must appear before this directive can be used. This directive
enables use of built-in functions such as GETC, PUTC, and PRINTF. The functions
created with this directive are exported when using multiple compilation units. To
access the correct function use the stream identifier.
When using parts with built-in SCI and the SCI pins are specified, the SCI will be
used. If a baud rate cannot be achieved within 3% of the desired value using the
current clock rate, an error will be generated. The definition of the RS232_ERRORS
is as follows:
No UART:
• Bit 7 is 9th bit for 9 bit data mode (get and put).
• Bit 6 set to one indicates a put failed in float high mode.
With a UART:
• Used only by get:
• Copy of RCSTA register except:
• Bit 0 is used to indicate a parity error.
Warning:
The PIC UART will shut down on overflow (3 characters received by the hardware
132
Pre-Processor Directives
with a GETC() call). The "ERRORS" option prevents the shutdown by detecting the
condition and resetting the UART.
Examples:
#use rs232(baud=9600, xmit=PIN_A2,rcv=PIN_A3)
Example Files: ex_cust.c
Also See:
getc(), putc(), printf(), setup_uart( ), RS2332 I/O overview
#USE RTOS
(The RTOS is only included with the PCW and PCWH packages.)
The CCS Real Time Operating System (RTOS) allows a PIC micro controller to run regularly scheduled
tasks without the need for interrupts. This is accomplished by a function (RTOS_RUN()) that acts as a
dispatcher. When a task is scheduled to run, the dispatch function gives control of the processor to that
task. When the task is done executing or does not need the processor anymore, control of the processor
is returned to the dispatch function which then will give control of the processor to the next task that is
scheduled to execute at the appropriate time. This process is called cooperative multi-tasking.
Syntax:
Elements:
Purpose:
#use rtos (options)
options are separated by comma and may be:
timer=X
Where x is 0-4 specifying the timer used by the RTOS.
minor_cycle=time
Where time is a number followed by s, ms, us, ns. This is
the longest time any task will run. Each task's execution
rate must be a multiple of this time. The compiler can
calculate this if it is not specified.
statistics
Maintain min, max, and total time used by each task.
This directive tells the compiler which timer on the PIC to use for
monitoring and when to grant control to a task. Changes to the specified timer's
prescaler will effect the rate at which tasks are executed.
This directive can also be used to specify the longest time that a task will ever take to
execute with the minor_cycle option. This simply forces all task execution rates to be
a multiple of the minor_cycle before the project will compile successfully. If the this
option is not specified the compiler will use a minor_cycle value that is the smallest
possible factor of the execution rates of the RTOS tasks.
If the statistics option is specified then the compiler will keep track of the minimum
processor time taken by one execution of each task, the maximum processor time
taken by one execution of each task, and the total processor time used by each task.
When linking multiple compilation units, this directive must appear exactly the same
in each compilation unit.
Examples:
#use rtos(timer=0, minor_cycle=20ms)
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#USE SPI
Syntax:
#use spi (options)
Elements:
Options are separated by commas and may be:
MASTER
Set the device as the master. (default)
SLAVE
Set the device as the slave.
BAUD=n
Target bits per second, default is as fast as possible.
CLOCK_HIGH=n
High time of clock in us (not needed if BAUD= is used).
(default=0)
CLOCK_LOW=n
Low time of clock in us (not needed if BAUD= is used).
(default=0)
DI=pin
Optional pin for incoming data.
DO=pin
Optional pin for outgoing data.
CLK=pin
Clock pin.
MODE=n
The mode to put the SPI bus.
ENABLE=pin
Optional pin to be active during data transfer.
LOAD=pin
Optional pin to be pulsed active after data is transferred.
DIAGNOSTIC=pin
Optional pin to the set high when data is sampled.
SAMPLE_RISE
Sample on rising edge.
SAMPLE_FALL
Sample on falling edge (default).
BITS=n
Max number of bits in a transfer. (default=32)
SAMPLE_COUNT=n
Number of samples to take (uses majority vote).
(default=1
LOAD_ACTIVE=n
Active state for LOAD pin (0, 1).
ENABLE_ACTIVE=n
Active state for ENABLE pin (0, 1). (default=0)
IDLE=n
Inactive state for CLK pin (0, 1). (default=0)
ENABLE_DELAY=n
Time in us to delay after ENABLE is activated. (default=0)
DATA_HOLD=n
Time between data change and clock change
LSB_FIRST
LSB is sent first.
MSB_FIRST
MSB is sent first. (default)
STREAM=id
Specify a stream name for this protocol.
SPI1
Use the hardware pins for SPI Port 1
SPI2
Use the hardware pins for SPI Port 2
FORCE_HW
Use the pic hardware SPI.
134
Pre-Processor Directives
Purpose:
The SPI library contains functions to implement an SPI bus. After setting all of
the proper parameters in #use spi, the spi_xfer() function can be used to both
transfer and receive data on the SPI bus.
The SPI1 and SPI2 options will use the SPI hardware onboard the PIC. The
most common pins present on hardware SPI are: DI, DO, and CLK. These pins
don’t need to be assigned values through the options; the compiler will
automatically assign hardware-specific values to these pins. Consult your PIC’s
data sheet as to where the pins for hardware SPI are. If hardware SPI is not
used, then software SPI will be used. Software SPI is much slower than
hardware SPI, but software SPI can use any pins to transfer and receive data
other than just the pins tied to the PIC’s hardware SPI pins.
The MODE option is more or less a quick way to specify how the stream is
going to sample data. MODE=0 sets IDLE=0 and SAMPLE_RISE. MODE=1
sets IDLE=0 and SAMPLE_FALL. MODE=2 sets IDLE=1 and SAMPLE_FALL.
MODE=3 sets IDLE=1 and SAMPLE_RISE. There are only these 4 MODEs.
SPI cannot use the same pins for DI and DO. If needed, specify two streams:
one to send data and another to receive data.
The pins must be specified with DI, DO, CLK or SPIx, all other options are
defaulted as indicated above.
Examples:
#use spi(DI=PIN_B1, DO=PIN_B0, CLK=PIN_B2, ENABLE=PIN_B4,
BITS=16)
// uses software SPI
#use spi(FORCE_HW, BITS=16, stream=SPI_STREAM)
// uses hardware SPI and gives this stream the name SPI_STREAM
Example Files:
None
Also See:
spi_xfer()
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#USE STANDARD_IO
Syntax:
#USE STANDARD_IO (port)
Elements:
port is A, B, C, D, E, F, G, H, J or ALL
Purpose:
This directive affects how the compiler will generate code for input and output
instructions that follow. This directive takes effect until another #use xxx_io
directive is encountered. The standard method of doing I/O will cause the
compiler to generate code to make an I/O pin either input or output every time it
is used. On the 5X processors this requires one byte of RAM for every port set
to standard I/O.
Standard_io is the default I/O method for all ports.
When linking multiple compilation units be aware this directive only applies to
the current compilation unit.
Examples:
#use standard_io(A)
Example Files:
Also See:
ex_cust.c
#use fast_io, #use fixed_io , General Purpose I/O
#USE TOUCHPAD
Syntax:
#USE TOUCHPAD (options)
Elements:
RANGE=x
Sets the oscillator charge/discharge current range. If x is L, current is nominally
0.1 microamps. If x is M, current is nominally 1.2 microamps. If x is H, current
is nominally 18 microamps. Default value is H (18 microamps).
THRESHOLD=x
x is a number between 1-100 and represents the percent reduction in the nominal
frequency that will generate a valid key press in software. Default value is 6%.
SCANTIME=xxMS
xx is the number of milliseconds used by the microprocessor to scan for one
key press. If utilizing multiple touch pads, each pad will use xx milliseconds to
scan for one key press. Default is 32ms.
PIN=char
If a valid key press is determined on “PIN”, the software will return the character
“char” in the function TOUCHPAD_GETC(). (Example: PIN_B0='A')
136
Pre-Processor Directives
Purpose:
This directive will tell the compiler to initialize and activate the Capacitive
Sensing Module (CSM) on the microcontroller. The compiler requires use of the
TIMER0 and TIMER1 modules, and global interrupts must still be activated in
the main program in order for the CSM to begin normal operation. For most
applications, a higher RANGE, lower THRESHOLD, and higher SCANTIME will
result better key press detection. Multiple PIN's may be declared in “options”,
but they must be valid pins used by the CSM. The user may also generate a
TIMER0 ISR with TIMER0's interrupt occuring every SCANTIME milliseconds.
In this case, the CSM's ISR will be executed first.
Examples:
#USE TOUCHPAD (THRESHOLD=5, PIN_D5='5', PIN_B0='C')
void main(void){
char c;
enable_interrupts(GLOBAL);
while(1){
c = TOUCHPAD_GETC(); //will wait until a pin is detected
}
//if PIN_B0 is pressed, c will have 'C'
}
//if PIN_D5 is pressed, c will have '5'
Example Files:
Also See:
None
touchpad_state( ), touchpad_getc( ), touchpad_hit( )
#WARNING
Syntax:
#warning text
Elements:
text is optional and may be any text
Purpose:
Forces the compiler to generate a warning at the location this directive appears
in the file. The text may include macros that will be expanded for the display.
This may be used to see the macro expansion. The command may also be
used to alert the user to an invalid compile time situation.
Examples:
#if BUFFER_SIZE < 32
#warning Buffer Overflow may occur
#endif
Example Files:
Also See:
ex_psp.c
#error
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#WORD
Syntax:
#word id = x
Elements:
id is a valid C identifier,
x is a C variable or a constant
Purpose:
If the id is already known as a C variable then this will locate the variable at
address x. In this case the variable type does not change from the original
definition. If the id is not known a new C variable is created and placed at
address x with the type int16
Warning: In both cases memory at x is not exclusive to this variable. Other
variables may be located at the same location. In fact when x is a variable, then
id and x share the same memory location.
Examples:
#word data = 0x0800
struct {
int lowerByte : 8;
int upperByte : 8;
} control_word;
#word control_word = 0x85
...
control_word.upperByte = 0x42;
Example Files:
Also See:
None
#bit, #byte, #locate, #reserve
#ZERO_RAM
Syntax:
#zero_ram
Elements:
Purpose:
None
This directive zero's out all of the internal registers that may be used to hold
variables before program execution begins.
Examples:
#zero_ram
void main() {
}
Example Files:
Also See:
138
ex_cust.c
None
BUILT-IN-FUNCTIONS
BUILT-IN-FUNCTIONS
The CCS compiler provides a lot of built-in functions to access and use the pic microcontroller's
peripherals. This makes it very easy for the users to configure and use the peripherals without
going into in depth details of the registers associated with the functionality. The functions
categorized by the peripherals associated with them are listed on the next page. Click on the
function name to get a complete description and parameter and return value descriptions.
assert( )
fgetc( )
fgets( )
fprintf( )
fputc( )
fputs( )
getch( )
getchar( )
gets( )
kbhit( )
perror( )
getc( )
putc( )
putchar( )
puts( )
setup_uart( )
set_uart_speed( )
printf( )
SPI TWO
WIRE I/O
setup_spi( )
setup_spi2( )
spi_xfer( )
spi_data_is_in( )
spi_data_is_in2( )
spi_read( )
spi_read2( )
DISCRETE
I/O
get_tris_x( )
input( )
input_state( )
set_tris_x( )
RS232 I/O
PARALLEL
PORT
psp_input_full( )
psp_overflow( )
input_x( )
output_X( )
output_bit( )
output_float( )
output_high( )
output_drive( )
spi_write( )
spi_write2( )
output_low( )
output_toggle( )
port_x_pullups( )
psp_output_full( )
setup_psp(option, address_mask)
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I2C I/O
PROCESSOR
CONTROLS
BIT/BYTE
MANIPULATION
STANDARD
C MATH
VOLTAGE REF
A/D
CONVERSION
140
i2c_isr_state( )
i2c_poll( )
i2c_read( )
i2c_slaveaddr( )
i2c_start( )
i2c_stop( )
i2c_write( )
clear_interrupt( )
disable_interrupts( )
enable_interrupts( )
ext_int_edge( )
getenv( )
brownout_enable( )
goto_address( )
interrupt_active( )
jump_to_isr( )
label_address( )
read_bank( )
reset_cpu( )
restart_cause( )
setup_oscillator( )
sleep( )
write_bank( )
bit_clear( )
bit_set( )
bit_test( )
make8( )
make16( )
make32( )
_mul( )
rotate_left( )
rotate_right( )
shift_left( )
shift_right( )
swap( )
abs( )
acos( )
asin( )
atan( )
atan2( )
atoe( )
ceil( )
cos( )
cosh( )
div( )
exp( )
fabs( )
floor( )
fmod( )
frexp( )
labs( )
ldexp( )
ldiv( )
log( )
log10( )
modf( )
pow( )
sin( )
sinh( )
sqrt( )
tan( )
tanh( )
setup_low_volt_detect( )
setup_vref( )
set_adc_channel( )
setup_adc( )
adc_done( )
setup_adc_ports( )
read_adc( )
Built-in-Functions
STANDARD C
CHAR / STRING
TIMERS
STANDARD
C MEMORY
CAPTURE/
COMPARE/PWM
atof( )
atoi( )
atol32( )
atol( )
isalnum( )
isalpha(char)
isamong( )
iscntrl(x)
isdigit(char)
isgraph(x)
islower(char)
isprint(x)
ispunct(x)
isspace(char)
isupper(char)
isxdigit(char)
itoa( )
sprintf( )
strcat( )
strchr( )
strcmp( )
strcoll( )
strcpy( )
strcspn( )
strerror( )
stricmp( )
strlen( )
strlwr( )
strncat( )
strncmp( )
strncpy( )
strpbrk( )
strrchr( )
strspn( )
strstr( )
strtod( )
strtok( )
strtol( )
strtoul( )
strxfrm( )
tolower( )
toupper( )
get_timer_x( )
setup_timer_1( )
setup_timer_4( )
restart_wdt( )
set_timer_x( )
setup_timer_2( )
setup_timer_5( )
setup_wdt( )
setup_timer_0( )
setup_timer_3( )
setup_counters( )
calloc( )
free( )
longjmp( )
malloc( )
memchr( )
memcmp( )
memcpy( )
memmove( )
memset( )
offsetof( )
offsetofbit( )
realloc( )
setjmp( )
set_power_pwm_override( )
set_power_pwmx_duty( )
set_pwm1_duty( )
set_pwm2_duty( )
set_pwm3_duty( )
set_pwm4_duty( )
set_pwm5_duty( )
setup_ccp1( )
setup_ccp2( )
setup_ccp3( )
setup_ccp4( )
setup_ccp5( )
setup_ccp6( )
setup_power_pwm( )
setup_power_pwm_pins( )
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NON-VOLATILE
MEMORY
STANDARD
C SPECIAL
DELAYS
ANALOG
COMPARE
RTOS
LCD
D/A
CONVERSION
CAPACITIVE
TOUCH PAD
MISC.
142
erase_eeprom( )
erase_program_eeprom( )
read_calibration( )
read_configuration_memory( )
read_eeprom( )
read_external_memory( )
read_program_eeprom( )
read_program_memory( )
setup_external_memory( )
write_configuration_memory( )
write_eeprom( )
write_external_memory( )
write_program_eeprom( )
write_program_memory( )
bsearch( )
nargs( )
srand( )
va_arg( )
qsort( )
rand( )
delay_cycles( )
delay_ms( )
va_end( )
va_start( )
delay_us( )
setup_comparator( )
rtos_await( )
rtos_disable( )
rtos_enable( )
rtos_msg_poll( )
rtos_msg_read( )
rtos_msg_send( )
rtos_overrun( )
rtos_run( )
rtos_signal( )
rtos_stats( )
rtos_terminate( )
rtos_wait( )
rtos_yield( )
lcd_load( )
lcd_symbol( )
setup_lcd( )
dac_write
setup_dac( )
touchpad_getc( )
touchpad_hit( )
setup_opamp1( )
setup_opamp2( )
touchpad_state( )
sleep_ulpwu( )
Built-in-Functions
abs( )
Syntax:
value = abs(x)
Parameters:
x is a signed 8, 16, or 32 bit int or a float
Returns:
Same type as the parameter.
Function:
Computes the absolute value of a number.
Availability:
All devices
Requires:
#include
Examples:
signed int target,actual;
...
error = abs(target-actual);
Example Files:
None
Also See:
labs()
adc_done( )
Syntax:
value = adc_done();
Parameters:
None
Returns:
A short int. TRUE if the A/D converter is done with conversion, FALSE if it is still
busy.
Function:
Can be polled to determine if the A/D has valid data.
Availability:
Only available on devices with built in analog to digital converters
Requires:
None
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C Compiler Reference Manual August 2009
Examples:
int16 value;
setup_adc_ports(sAN0|sAN1, VSS_VDD);
setup_adc(ADC_CLOCK_DIV_4|ADC_TAD_MUL_8);
set_adc_channel(0);
read_adc(ADC_START_ONLY);
int1 done = adc_done();
while(!done) {
done = adc_done();
}
value = read_adc();
printf(“A/C value = %LX\n\r”, value);
}
Example Files:
Also See:
None
setup_adc(), set_adc_channel(), setup_adc_ports(), read_adc(), adc overview
assert( )
Syntax:
assert (condition);
Parameters:
condition is any relational expression
Returns:
Nothing
Function:
This function tests the condition and if FALSE will generate an error message
on STDERR (by default the first USE RS232 in the program). The error
message will include the file and line of the assert(). No code is generated for
the assert() if you #define NODEBUG. In this way you may include asserts in
your code for testing and quickly eliminate them from the final program.
Availability:
All devices
Requires:
assert.h and #use rs232
Examples:
assert( number_of_entries= TABLE_SIZE then
// the following is output at the RS232:
// Assertion failed, file myfile.c, line 56
Example Files:
Also See:
144
None
#use rs232, RS232 I/O overview
Built-in-Functions
atoe( )
Syntax:
write_program_memory( address, dataptr, count );
Parameters:
string is a pointer to a null terminated string of characters.
Returns:
Function:
Result is a floating point number
Converts the string passed to the function into a floating point representation. If
the result cannot be represented, the behavior is undefined. This function also
handles E format numbers.
All devices
#include
Availability:
Requires:
Examples:
char string [10];
float32 x;
strcpy (string, "12E3");
x = atoe(string);
// x is now 12000.00
Example Files:
Also See:
None
atoi(),atol(), atoi32(), atof(), printf()
atof( )
Syntax:
result = atof (string)
Parameters:
string is a pointer to a null terminated string of characters.
Returns:
Result is a floating point number
Function:
Converts the string passed to the function into a floating point representation. If
the result cannot be represented, the behavior is undefined.
Availability:
Requires:
All devices
#include
Examples:
char string [10];
float x;
strcpy (string, "123.456");
x = atof(string);
// x is now 123.456
Example Files:
Also See:
ex_tank.c
atoi(), atol(), atoi32(), printf()
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atoi( )
atol( )
atoi32( )
Syntax:
ivalue = atoi(string)
or
lvalue = atol(string)
or
i32value = atoi32(string)
Parameters:
string is a pointer to a null terminated string of characters.
Returns:
ivalue is an 8 bit int.
lvalue is a 16 bit int.
i32value is a 32 bit int.
Function:
Converts the string passed to the function into an int representation. Accepts
both decimal and hexadecimal argument. If the result cannot be represented,
the behavior is undefined.
Availability:
All devices
Requires:
#include
Examples:
char string[10];
int x;
strcpy(string,"123");
x = atoi(string);
// x is now 123
Example Files:
input.c
Also See:
printf()
146
Built-in-Functions
bit_clear( )
Syntax:
bit_clear(var, bit)
Parameters:
var may be a any bit variable (any lvalue)
bit is a number 0-31 representing a bit number, 0 is the least significant bit.
Returns:
Function:
undefined
Simply clears the specified bit (0-7, 0-15 or 0-31) in the given variable. The
least significant bit is 0. This function is the similar to: var &= ~(1<
Examples:
int nums[5]={1,2,3,4,5};
int compar(const void *arg1,const void *arg2);
void main() {
int *ip, key;
key = 3;
ip = bsearch(&key, nums, 5, sizeof(int), compar);
}
int compar(const void *arg1,const void *arg2) {
if ( * (int *) arg1 < ( * (int *) arg2) return –1
else if ( * (int *) arg1 == ( * (int *) arg2) return 0
else return 1;
}
Example Files:
None
Also See:
qsort()
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calloc( )
Syntax:
ptr=calloc(nmem, size)
Parameters:
nmem is an integer representing the number of member objects, and size is the
number of bytes to be allocated for each one of them.
Returns:
A pointer to the allocated memory, if any. Returns null otherwise.
Function:
The calloc function allocates space for an array of nmem objects whose size is
specified by size. The space is initialized to all bits zero.
Availability:
Requires:
All devices
#include
Examples:
int * iptr;
iptr=calloc(5,10);
// iptr will point to a block of memory of
// 50 bytes all initialized to 0.
Example Files:
Also See:
None
realloc(), free(), malloc()
ceil( )
Syntax:
result = ceil (value)
Parameters:
value is a float
Returns:
A float
Function:
Computes the smallest integer value greater than the argument. CEIL(12.67) is 13.00.
Availability:
Requires:
All devices
#include
Examples:
// Calculate cost based on weight rounded
// up to the next pound
cost = ceil( weight ) * DollarsPerPound;
Example Files:
Also See:
150
None
floor()
Built-in-Functions
clear_interrupt( )
Syntax:
clear_interrupt(level)
Parameters:
level - a constant defined in the devices.h file
Returns:
undefined
Function:
Clears the interrupt flag for the given level. This function is designed for use
with a specific interrupt, thus eliminating the GLOBAL level as a possible
parameter. Some chips that have interrupt on change for individual pins allow
the pin to be specified like INT_RA1.
Availability:
Requires:
Examples:
All devices
Nothing
Example Files:
Also See:
None
enable_interrupts(), #INT, Interrupts overview
clear_interrupt(int_timer1);
dac_write( )
Syntax:
dac_write (value)
Parameters:
Value: 8-bit integer value to be written to the DAC module
Returns:
Function:
undefined
This function will write a 8-bit integer to the specified DAC channel.
Availability:
Only available on devices with built in digital to analog converters.
Requires:
Examples:
Nothing
Also See:
setup_dac( ), DAC overview, see header file for device selected
int i = 0;
setup_dac(DAC_VDD | DAC_OUTPUT);
while(1){
i++;
dac_write(i);
}
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delay_cycles( )
Syntax:
delay_cycles (count)
Parameters:
count - a constant 1-255
Returns:
Function:
undefined
Creates code to perform a delay of the specified number of instruction clocks
(1-255). An instruction clock is equal to four oscillator clocks.
The delay time may be longer than requested if an interrupt is serviced during
the delay. The time spent in the ISR does not count toward the delay time.
Availability:
Requires:
Examples:
All devices
Nothing
delay_cycles( 1 ); // Same as a NOP
delay_cycles(25); // At 20 mhz a 5us delay
Example Files:
ex_cust.c
Also See:
delay_us(), delay_ms()
delay_ms( )
Syntax:
delay_ms (time)
Parameters:
time - a variable 0-65535(int16) or a constant 0-65535
Note: Previous compiler versions ignored the upper byte of an int16, now the
upper byte affects the time.
Returns:
Function:
undefined
This function will create code to perform a delay of the specified length. Time is
specified in milliseconds. This function works by executing a precise number of
instructions to cause the requested delay. It does not use any timers. If
interrupts are enabled the time spent in an interrupt routine is not counted
toward the time.
The delay time may be longer than requested if an interrupt is serviced during
the delay. The time spent in the ISR does not count toward the delay time.
Availability:
152
All devices
Built-in-Functions
Requires:
#use delay
Examples:
#use delay (clock=20000000)
delay_ms( 2 );
void delay_seconds(int n) {
for (;n!=0; n- -)
delay_ms( 1000 );
}
Example Files:
ex_sqw.c
Also See:
delay_us(), delay_cycles(), #use delay
delay_us( )
Syntax:
delay_us (time)
Parameters:
time - a variable 0-65535(int16) or a constant 0-65535
Note: Previous compiler versions ignored the upper byte of an int16, now the
upper byte affects the time.
Returns:
Undefined
Function:
Creates code to perform a delay of the specified length. Time is specified in
microseconds. Shorter delays will be INLINE code and longer delays and
variable delays are calls to a function. This function works by executing a precise
number of instructions to cause the requested delay. It does not use any timers.
If interrupts are enabled the time spent in an interrupt routine is not counted
toward the time.
The delay time may be longer than requested if an interrupt is serviced during
the delay. The time spent in the ISR does not count toward the delay time.
Availability:
All devices
Requires:
#use delay
Examples:
#use delay(clock=20000000)
do {
output_high(PIN_B0);
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delay_us(duty);
output_low(PIN_B0);
delay_us(period-duty);
} while(TRUE);
Example Files:
ex_sqw.c
Also See:
delay_ms(), delay_cycles(), #use delay
diable_interrupts( )
Syntax:
disable_interrupts (level)
Parameters:
Returns:
Function:
level - a constant defined in the devices .h file
undefined
Disables the interrupt at the given level. The GLOBAL level will not disable any
of the specific interrupts but will prevent any of the specific interrupts, previously
enabled to be active. Valid specific levels are the same as are used in
#INT_xxx and are listed in the devices .h file. GLOBAL will also disable the
peripheral interrupts on devices that have it. Note that it is not necessary to
disable interrupts inside an interrupt service routine since interrupts are
automatically disabled. Some chips that have interrupt on change for individual
pins allow the pin to be specified like INT_RA1.
Availability:
Device with interrupts (PCM and PCH)
Requires:
Should have a #int_xxxx, constants are defined in the devices .h file.
Examples:
disable_interrupts(GLOBAL); // all interrupts OFF
disable_interrupts(INT_RDA); // RS232 OFF
enable_interrupts(ADC_DONE);
enable_interrupts(RB_CHANGE);
// these enable the interrupts
// but since the GLOBAL is disabled they
// are not activated until the following
// statement:
enable_interrupts(GLOBAL);
Example Files:
Also See:
154
ex_sisr.c, ex_stwt.c
enable_interrupts(), clear_interrupt (), #int_xxxx, Interrupts overview
Built-in-Functions
div( )
ldiv( )
Syntax:
idiv=div(num, denom)
ldiv =ldiv(lnum, ldenom)
Parameters:
num and denom are signed integers.
num is the numerator and denom is the denominator.
lnum and ldenom are signed longs
lnum is the numerator and ldenom is the denominator.
Returns:
idiv is a structure of type div_t and lidiv is a structure of type ldiv_t. The div
function returns a structure of type div_t, comprising of both the quotient and
the remainder. The ldiv function returns a structure of type ldiv_t, comprising of
both the quotient and the remainder.
Function:
The div and ldiv function computes the quotient and remainder of the division of
the numerator by the denominator. If the division is inexact, the resulting
quotient is the integer or long of lesser magnitude that is the nearest to the
algebraic quotient. If the result cannot be represented, the behavior is
undefined; otherwise quot*denom(ldenom)+rem shall equal num(lnum).
Availability:
All devices.
Requires:
#include
Examples:
div_t idiv;
ldiv_t lidiv;
idiv=div(3,2);
//idiv will contain quot=1 and rem=1
lidiv=ldiv(300,250);
//lidiv will contain lidiv.quot=1 and lidiv.rem=50
Example Files:
None
Also See:
None
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enable_interrupts( )
Syntax:
enable_interrupts (level)
Parameters:
level - a constant defined in the devices .h file
Returns:
Function:
undefined
Enables the interrupt at the given level. An interrupt procedure should have been
defined for the indicated interrupt. The GLOBAL level will not enable any of the
specific interrupts but will allow any of the specific interrupts previously enabled
to become active. Some chips that have interrupt on change for individual pins
allow the pin to be specified like INT_RA1.
Enabling an interrupt does not clear the interrupt flag if there was a pending
interrupt prior to the call. Use clear_interrupt to clear pending interrupts before
the call to enable_interrupts to discard prior interrupts.
Availability:
Device with interrupts (PCM and PCH)
Requires:
Should have a #int_xxxx, Constants are defined in the devices .h file.
Examples:
enable_interrupts(GLOBAL);
enable_interrupts(INT_TIMER0);
enable_interrupts(INT_TIMER1);
Example Files:
ex_sisr.c, ex_stwt.c
Also See:
disable_enterrupts(), clear_interrupt (), #int_xxxx, Interrupts overview
erase_eeprom
Syntax:
erase_eeprom (address);
Parameters:
address is 8 bits on PCB parts.
Returns:
Function:
undefined
This will erase a row of the EEPROM or Flash Data Memory.
Availability:
PCB devices with EEPROM like the 12F519
Requires:
Examples:
Nothing
Example Files:
Also See:
None
write program eeprom(), write program memory(), program eeprom overview
156
erase_eeprom(0);
bytes)
// erase the first row of the EEPROM (8
Built-in-Functions
erase_program_eeprom( )
Syntax:
erase_program_eeprom (address);
Parameters:
address is 16 bits on PCM parts and 32 bits on PCH parts. The least
significant bits may be ignored.
Returns:
Function:
undefined
Erases FLASH_ERASE_SIZE bytes to 0xFFFF in program memory.
FLASH_ERASE_SIZE varies depending on the part. For example, if it is 64
bytes then the least significant 6 bits of address is ignored.
See WRITE_PROGRAM_MEMORY for more information on program memory
access.
Availability:
Only devices that allow writes to program memory.
Requires:
Examples:
Nothing
Example Files:
Also See:
None
write program eeprom(), write program memory(), program eeprom overview
for(i=0x1000;i<=0x1fff;i+=getenv("FLASH_ERASE_SIZE"))
erase_program_memory(i);
exp( )
Syntax:
result = exp (value)
Parameters:
value is a float
Returns:
A float
Function:
Computes the exponential function of the argument. This is e to the power of
value where e is the base of natural logarithms. exp(1) is 2.7182818.
Note on error handling:
If "errno.h" is included then the domain and range errors are stored in the errno
variable. The user can check the errno to see if an error has occurred and print
the error using the perror function.
Range error occur in the following case:
• exp: when the argument is too large
Availability:
All devices
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Requires:
#include
Examples:
// Calculate x to the power of y
x_power_y = exp( y * log(x) );
Example Files:
Also See:
None
pow(), log(), log10()
ext_int_edge( )
Syntax:
ext_int_edge (source, edge)
Parameters:
source is a constant 0,1 or 2 for the PIC18XXX and 0 otherwise. Source is
optional and defaults to 0.
edge is a constant H_TO_L or L_TO_H representing "high to low" and "low to
high"
Returns:
undefined
Function:
Determines when the external interrupt is acted upon. The edge may be
L_TO_H or H_TO_L to specify the rising or falling edge.
Availability:
Only devices with interrupts (PCM and PCH)
Requires:
Constants are in the devices .h file
Examples:
ext_int_edge( 2, L_TO_H); // Set up PIC18 EXT2
ext_int_edge( H_TO_L );
// Sets up EXT
Example Files:
ex_wakup.c
Also See:
#INT_EXT, enable_interrupts(), disable_interrupts(), Interrupts overview
158
Built-in-Functions
fabs( )
Syntax:
result=fabs (value)
Parameters:
value is a float
Returns:
result is a float
Function:
The fabs function computes the absolute value of a float
Availability:
Requires:
All devices.
#include
Examples:
float result;
result=fabs(-40.0)
// result is 40.0
Example Files:
Also See:
None
abs(), labs()
floor( )
Syntax:
result = floor (value)
Parameters:
value is a float
Returns:
result is a float
Function:
Computes the greatest integer value not greater than the argument. Floor
(12.67) is 12.00.
Availability:
Requires:
All devices.
#include
Examples:
// Find the fractional part of a value
frac = value - floor(value);
Example Files:
Also See:
None
ceil()
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fmod( )
Syntax:
result= fmod (val1, val2)
Parameters:
val1 is a float
val2 is a float
Returns:
result is a float
Function:
Returns the floating point remainder of val1/val2. Returns the value val1 - i*val2
for some integer “i” such that, if val2 is nonzero, the result has the same sign as
val1 and magnitude less than the magnitude of val2.
Availability:
Requires:
All devices.
#include
Examples:
float result;
result=fmod(3,2);
// result is 1
Example Files:
Also See:
None
None
free( )
Syntax:
free(ptr)
Parameters:
ptr is a pointer earlier returned by the calloc, malloc or realloc.
Returns:
Function:
No value
The free function causes the space pointed to by the ptr to be deallocated, that
is made available for further allocation. If ptr is a null pointer, no action occurs.
If the ptr does not match a pointer earlier returned by the calloc, malloc or
realloc, or if the space has been deallocated by a call to free or realloc function,
the behavior is undefined.
Availability:
Requires:
All devices.
#include
Examples:
int * iptr;
iptr=malloc(10);
free(iptr)
// iptr will be deallocated
Example Files:
Also See:
None
realloc(), malloc(), calloc()
160
Built-in-Functions
frexp( )
Syntax:
result=frexp (value, & exp);
Parameters:
value is a float
exp is a signed int.
Returns:
result is a float
Function:
The frexp function breaks a floating point number into a normalized fraction and
an integral power of 2. It stores the integer in the signed int object exp. The
result is in the interval [1/2,1) or zero, such that value is result times 2 raised to
power exp. If value is zero then both parts are zero.
Availability:
All devices.
Requires:
#include
Examples:
float result;
signed int exp;
result=frexp(.5,&exp);
// result is .5 and exp is 0
Example Files:
Also See:
None
ldexp(), exp(), log(), log10(), modf()
get_timerx( )
Syntax:
value=get_timer0() Same as:
value=get_timer1()
value=get_timer2()
value=get_timer3()
value=get_timer4()
value=get_timer5()
Parameters:
Returns:
None
Timers 1, 3, and 5 return a 16 bit int.
Timers 2 and 4 return an 8 bit int.
Timer 0 (AKA RTCC) returns a 8 bit int except on the PIC18XXX where it
returns a 16 bit int.
Returns the count value of a real time clock/counter. RTCC and Timer0 are the
same. All timers count up. When a timer reaches the maximum value it will flip
over to 0 and continue counting (254, 255, 0, 1, 2...).
Timer 0 - All devices
Function:
Availability:
value=get_rtcc()
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Timers 1 & 2 - Most but not all PCM devices
Timer 3 - Only PIC18XXX
Timer 4 - Some PCH devices
Timer 5 - Only PIC18XX31
Requires:
Examples:
Nothing
Example Files:
ex_stwt.c
Also See:
set_timerx(), Timer0 overview, Timer1 overview, Timer2 overview, Timer5 overview
set_timer0(0);
while ( get_timer0() < 200 ) ;
get_tris_x( )
Syntax:
value = get_tris_A();
value = get_tris_B();
value = get_tris_C();
value = get_tris_D();
value = get_tris_E();
value = get_tris_F();
value = get_tris_G();
value = get_tris_H();
value = get_tris_J();
value = get_tris_K()
Parameters:
Returns:
None
int16, the value of TRIS register
Function:
Returns the value of the TRIS register of port A, B, C, D, E, F, G, H, J, or K.
Availability:
All devices.
Requires:
Examples:
Nothing
Example Files:
Also See:
None
input(), output_low(), output_high()
162
tris_a = GET_TRIS_A();
Built-in-Functions
getc( )
getch( )
getchar( )
fgetc( )
Syntax:
value = getc()
value = fgetc(stream)
value=getch()
value=getchar()
Parameters:
stream is a stream identifier (a constant byte)
Returns:
An 8 bit character
Function:
This function waits for a character to come in over the RS232 RCV pin and returns
the character. If you do not want to hang forever waiting for an incoming character
use kbhit() to test for a character available. If a built-in USART is used the hardware
can buffer 3 characters otherwise GETC must be active while the character is being
received by the PIC®.
If fgetc() is used then the specified stream is used where getc() defaults to
STDIN (the last USE RS232).
Availability:
Requires:
All devices
#use rs232
Examples:
printf("Continue (Y,N)?");
do {
answer=getch();
}while(answer!='Y' && answer!='N');
#use rs232(baud=9600,xmit=pin_c6,
rcv=pin_c7,stream=HOSTPC)
#use rs232(baud=1200,xmit=pin_b1,
rcv=pin_b0,stream=GPS)
#use rs232(baud=9600,xmit=pin_b3,
stream=DEBUG)
...
while(TRUE) {
c=fgetc(GPS);
fputc(c,HOSTPC);
if(c==13)
fprintf(DEBUG,"Got a CR\r\n");
}
Example Files:
ex_stwt.c
Also See:
putc(), kbhit(), printf(), #use rs232, input.c, RS232 I/O overview
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getenv( )
Syntax:
Parameters:
Returns:
Function:
164
value = getenv (cstring);
cstring is a constant string with a recognized keyword
A constant number, a constant string or 0
This function obtains information about the execution environment. The following
are recognized keywords. This function returns a constant 0 if the keyword is not
understood.
FUSE_SET:fffff
fffff Returns 1 if fuse fffff is enabled
FUSE_VALID:fffff
fffff Returns 1 if fuse fffff is valid
INT:iiiii
Returns 1 if the interrupt iiiii is valid
ID
Returns the device ID (set by #ID)
DEVICE
Returns the device name string (like "PIC16C74")
CLOCK
Returns the MPU FOSC
ICD
Returns 1 if the ICD=TRUE Mode is active
VERSION
Returns the compiler version as a float
VERSION_STRING
Returns the compiler version as a string
PROGRAM_MEMORY
Returns the size of memory for code (in words)
STACK
Returns the stack size
SCRATCH
Returns the start of the compiler scratch area
DATA_EEPROM
Returns the number of bytes of data EEPROM
EEPROM_ADDRESS
Returns the address of the start of EEPROM. 0 if
not supported by the device.
READ_PROGRAM
Returns a 1 if the code memory can be read
PIN:pb
Returns a 1 if bit b on port p is on this part
ADC_CHANNELS
Returns the number of A/D channels
ADC_RESOLUTION
Returns the number of bits returned from
READ_ADC()
ICD
Returns a 1 if this is being compiled for a ICD
SPI
Returns a 1 if the device has SPI
USB
Returns a 1 if the device has USB
CAN
Returns a 1 if the device has CAN
I2C_SLAVE
Returns a 1 if the device has I2C slave H/W
I2C_MASTER
Returns a 1 if the device has I2C master H/W
PSP
Returns a 1 if the device has PSP
COMP
Returns a 1 if the device has a comparator
VREF
Returns a 1 if the device has a voltage reference
LCD
Returns a 1 if the device has direct LCD H/W
UART
Returns the number of H/W UARTs
AUART
Returns 1 if the device has an ADV UART
CCPx
Returns a 1 if the device has CCP number x
TIMERx
Returns a 1 if the device has TIMER number x
Built-in-Functions
FLASH_WRITE_SIZE
FLASH_ERASE_SIZE
BYTES_PER_ADDRESS
BITS_PER_INSTRUCTION
RAM
SFR:name
BIT:name
PIN:PB
Availability:
Requires:
Examples:
Smallest number of bytes that can be written to
FLASH
Smallest number of bytes that can be erased in
FLASH
Returns the number of bytes at an address
location
Returns the size of an instruction in bits
Returns the number of RAM bytes available for
your device.
Returns the address of the specified special file
register. The output format can be used with the
preprocessor command #bit. name must match
SFR denomination of your target PIC (example:
STATUS, INTCON, TXREG, RCREG, etc)
Returns the bit address of the specified special
file register bit. The output format will be in
“address:bit”, which can be used with the
preprocessor command #byte. name must match
SFR.bit denomination of your target PIC
(example: C, Z, GIE, TMR0IF, etc)
Returns 1 if PB is a valid I/O PIN (like A2)
All devices
Nothing
#IF getenv("VERSION")<3.050
#ERROR Compiler version too old
#ENDIF
for(i=0;i= 0x80)
i2c_write(send_buffer[state - 0x80]);
else if(state > 0)
rcv_buffer[state - 1] = i2c_read();
}
Example Files:
ex_slave.c
Also See:
i2c_write, i2c_read, #use i2c
i2c_poll( )
Syntax:
i2c_poll()
i2c_poll(stream)
Parameters:
stream (optional)- specify the stream defined in #USE I2C
Returns:
1 (TRUE) or 0 (FALSE)
Function:
The I2C_POLL() function should only be used when the built-in SSP is used.
This function returns TRUE if the hardware has a received byte in the buffer.
When a TRUE is returned, a call to I2C_READ() will immediately return the byte
that was received.
Availability:
Devices with built in I2C
Requires:
#use i2c
168
Built-in-Functions
Examples:
i2c_start();
// Start condition
i2c_write(0xc1); // Device address/Read
count=0;
while(count!=4) {
while(!i2c_poll()) ;
buffer[count++]= i2c_read(); //Read Next
}
i2c_stop();
// Stop condition
Example Files:
ex_slave.c
Also See:
i2c_start, i2c_write, i2c_stop ,i2c overview
I2C_read( )
Syntax:
data = i2c_read();
data = i2c_read(ack);
data = i2c_read(stream, ack);
Parameters:
ack -Optional, defaults to 1.
0 indicates do not ack.
1 indicates to ack.
stream - specify the stream defined in #USE I2C
Returns:
data - 8 bit int
Function:
Reads a byte over the I2C interface. In master mode this function will generate
the clock and in slave mode it will wait for the clock. There is no timeout for the
slave, use I2C_POLL to prevent a lockup. Use RESTART_WDT in the #USE
I2C to strobe the watch-dog timer in the slave mode while waiting.
Availability:
Devices with built in I2C
Requires:
#use i2c
Examples:
i2c_start();
i2c_write(0xa1);
data1 = i2c_read();
data2 = i2c_read();
i2c_stop();
Example Files:
ex_extee.c with 2416.c
Also See:
i2c_start, i2c_write, i2c_stop, i2c_poll, i2c overview
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C Compiler Reference Manual August 2009
i2c_slaveaddr( )
Syntax:
I2C_SlaveAddr(addr);
I2C_SlaveAddr(stream, addr);
Parameters:
addr = 8 bit device address
stream(optional) - specifies the stream used in #USE I2C
Returns:
Function:
Nothing
This functions sets the address for the I2C interface in slave mode.
Availability:
Devices with built in I2C
Requires:
#use i2c
Examples:
i2c_SlaveAddr(0x08);
i2c_SlaveAddr(i2cStream1, 0x08);
Example Files:
ex_slave.c
Also See:
i2c_start, i2c_write, i2c_stop, i2c_poll, #use i2c , i2c overview
i2c_start( )
Syntax:
i2c_start()
i2c_start(stream)
i2c_start(stream, restart)
Parameters:
stream: specify the stream defined in #USE I2C
restart: 2 – new restart is forced instead of start
1 – normal start is performed
0 (or not specified) – restart is done only if the compiler last encountered a
I2C_START and no I2C_STOP
Returns:
Function:
undefined
Issues a start condition when in the I2C master mode. After the start condition
the clock is held low until I2C_WRITE() is called. If another I2C_start is called in
the same function before an i2c_stop is called, then a special restart condition
is issued. Note that specific I2C protocol depends on the slave device. The
I2C_START function will now accept an optional parameter. If 1 the compiler
assumes the bus is in the stopped state. If 2 the compiler treats this
I2C_START as a restart. If no parameter is passed a 2 is used only if the
compiler compiled a I2C_START last with no I2C_STOP since.
All devices.
Availability:
170
Built-in-Functions
Requires:
#use i2c
Examples:
i2c_start();
i2c_write(0xa0);
i2c_write(address);
i2c_start();
i2c_write(0xa1);
data=i2c_read(0);
i2c_stop();
//
//
//
//
//
Device address
Data to device
Restart
to change data direction
Now read from slave
Example Files:
ex_extee.c with 2416.c
Also See:
i2c_write, i2c_stop, i2c_poll, i2c overview
i2c_stop( )
Syntax:
i2c_stop()
i2c_stop(stream)
Parameters:
stream: (optional) specify stream defined in #USE I2C
Returns:
undefined
Function:
Issues a stop condition when in the I2C master mode.
Availability:
All devices.
Requires:
#use i2c
Examples:
i2c_start();
i2c_write(0xa0);
i2c_write(5);
i2c_write(12);
i2c_stop();
Example Files:
ex_extee.c with 2416.c
Also See:
i2c_start, i2c_write, i2c_read, i2c_poll, #use i2c , i2c overview
//
//
//
//
//
Start condition
Device address
Device command
Device data
Stop condition
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i2c_write( )
Syntax:
i2c_write (data)
i2c_write (stream, data)
Parameters:
data is an 8 bit int
stream - specify the stream defined in #USE I2C
Returns:
This function returns the ACK Bit.
0 means ACK, 1 means NO ACK, 2 means there was a collision if in
Multi_Master Mode.
This does not return an ACK if using i2c in slave mode.
Function:
Sends a single byte over the I2C interface. In master mode this function will
generate a clock with the data and in slave mode it will wait for the clock from
the master. No automatic timeout is provided in this function. This function
returns the ACK bit. The LSB of the first write after a start determines the
direction of data transfer (0 is master to slave). Note that specific I2C protocol
depends on the slave device.
Availability:
All devices.
Requires:
#use i2c
Examples:
long cmd;
...
i2c_start();
// Start condition
i2c_write(0xa0);// Device address
i2c_write(cmd);// Low byte of command
i2c_write(cmd>>8);// High byte of command
i2c_stop();
// Stop condition
Example Files:
ex_extee.c with 2416.c
Also See:
i2c_start(), i2c_stop, i2c_read, i2c_poll, #use i2c, i2c overview
172
Built-in-Functions
i2c_speed( )
Syntax:
i2c_speed (baud)
i2c_speed (stream, baud)
Parameters:
baud is the number of bits per second.
stream - specify the stream defined in #USE I2C
Returns:
Nothing.
Function:
This function changes the I2c bit rate at run time. This only works if the
hardware I2C module is being used.
Availability:
All devices.
Requires:
#use i2c
Examples:
I2C_Speed (400,000);
Example Files:
Also See:
none
i2c_start(), i2c_stop, i2c_read, i2c_poll, #use i2c, i2c overview
input( )
Syntax:
value = input (pin)
Parameters:
Pin to read. Pins are defined in the devices .h file. The actual value is a bit
address. For example, port a (byte 5) bit 3 would have a value of 5*8+3 or 43.
This is defined as follows: #define PIN_A3 43.
Returns:
The PIN could also be a variable. The variable must have a value equal to one
of the constants (like PIN_A1) to work properly. The tristate register is updated
unless the FAST_I0 mode is set on port A. Note that doing I/0 with a variable
instead of a constant will take much longer time.
0 (or FALSE) if the pin is low,
1 (or TRUE) if the pin is high
Function:
This function returns the state of the indicated pin. The method of I/O is
dependent on the last USE *_IO directive. By default with standard I/O before
the input is done the data direction is set to input.
Availability:
All devices.
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Requires:
Pin constants are defined in the devices .h file
Examples:
while ( !input(PIN_B1) );
// waits for B1 to go high
if( input(PIN_A0) )
printf("A0 is now high\r\n");
int16 i=PIN_B1;
while(!i);
//waits for B1 to go high
Example Files:
ex_pulse.c
Also See:
input_x(), output_low(), output_high(), #use fixed_io, #use fast_io, #use
standard_io, General Purpose I/O
input_state( )
Syntax:
value = input_state(pin)
Parameters:
pin to read. Pins are defined in the devices .h file. The actual value is a bit
address. For example, port a (byte 5) bit 3 would have a value of 5*8+3 or 43.
This is defined as follows: #define PIN_A3 43.
Returns:
Bit specifying whether pin is high or low. A 1 indicates the pin is high and a 0
indicates it is low.
Function:
This function reads the level of a pin without changing the direction of the pin as
INPUT() does.
Availability:
All devices.
Requires:
Nothing
Examples:
level = input_state(pin_A3);
printf("level: %d",level);
Example Files:
None
Also See:
input(), set_tris_x(), output_low(), output_high(), General Purpose I/O
174
Built-in-Functions
input_x( )
Syntax:
value = input_a()
value = input_b()
value = input_c()
value = input_d()
value = input_e()
value = input_f()
value = input_g()
value = input_h()
value = input_j()
value = input_k()
Parameters:
Returns:
Function:
None
An 8 bit int representing the port input data.
Inputs an entire byte from a port. The direction register is changed in
accordance with the last specified #USE *_IO directive. By default with
standard I/O before the input is done the data direction is set to input.
Availability:
Requires:
Examples:
Example Files:
Also See:
All devices.
Nothing
data = input_b();
ex_psp.c
input(), output_x(), #use fixed_io, #use fast_io, #use standard_io
interrupt_active( )
Syntax:
interrupt_active (interrupt)
Parameters:
Interrupt – constant specifying the interrupt
Returns:
Boolean value
Function:
The function checks the interrupt flag of the specified interrupt and returns true
in case the flag is set.
Availability:
Requires:
Examples:
Device with interrupts (PCM and PCH)
Should have a #int_xxxx, Constants are defined in the devices .h file.
Example Files:
Also See:
None
disable_enterrupts(), #INT, Interrupts overview
interrupt_active(INT_TIMER0);
interrupt_active(INT_TIMER1);
175
isalnum(char)
isalpha(char)
isdigit(char)
Syntax:
Parameters:
Returns:
Function:
Availability:
Requires:
Examples:
Example Files:
Also See:
islower(char)
isspace(char)
isupper(char)
isxdigit(char)
iscntrl(x)
isgraph(x)
isprint(x)
ispunct(x)
value = isalnum(datac)
value = isalpha(datac)
value = isdigit(datac)
value = islower(datac)
value = isspace(datac)
value = isupper(datac)
value = isxdigit(datac)
value = iscntrl(datac)
value = isgraph(datac)
value = isprint(datac)
value = punct(datac)
datac is a 8 bit character
0 (or FALSE) if datac dose not match the criteria, 1 (or TRUE) if datac does match the criteria.
Tests a character to see if it meets specific criteria as follows:
isalnum(x)
X is 0..9, 'A'..'Z', or 'a'..'z'
isalpha(x)
X is 'A'..'Z' or 'a'..'z
isdigit(x)
X is '0'..'9'
islower(x)
X is 'a'..'z'
isupper(x)
X is 'A'..'Z
isspace(x)
X is a space
isxdigit(x)
X is '0'..'9', 'A'..'F', or 'a'..'f
iscntrl(x)
X is less than a space
isgraph(x)
X is greater than a space
isprint(x)
X is greater than or equal to a space
ispunct(x)
X is greater than a space and not a letter or number
All devices.
#include
char id[20];
...
if(isalpha(id[0])) {
valid_id=TRUE;
for(i=1;i
Also See:
isalnum( ), isalpha( ), isdigit( ), isspace( ), islower( ), isupper( ), isxdigit( )
char x= 'x';
...
if ( isamong ( x,
"0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ") )
printf ("The character is valid");
itoa( )
Syntax:
string = itoa(i32value, i8base, string)
Parameters:
i32value is a 32 bit int
i48value is a 48 bit int
i64value is a 64 bit int
i8base is a 8 bit int
string is a pointer to a null terminated string of characters
Returns:
string is a pointer to a null terminated string of characters
Function:
Converts the signed int32 to a string according to the provided base and returns
the converted value if any. If the result cannot be represented, the function will
return 0.
Availability:
All devices
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Requires:
#include
Examples:
int32 x=1234;
char string[5];
itoa(x,10, string);
// string is now “1234”
Example Files:
Also See:
None
None
jump_to_isr
Syntax:
jump_to_isr (address)
Parameters:
address is a valid program memory address
Returns:
No value
Function:
The jump_to_isr function is used when the location of the interrupt service
routines are not at the default location in program memory. When an interrupt
occurs, program execution will jump to the default location and then jump to the
specified address.
Availability:
All devices
Requires:
Nothing
Examples:
int_global
void global_isr(void) {
jump_to_isr(isr_address);
}
Example Files:
ex_bootloader.c
Also See:
#build( )
178
Built-in-Functions
kbhit( )
Syntax:
value = kbhit()
value = kbhit (stream)
Parameters:
stream is the stream id assigned to an available RS232 port. If the stream
parameter is not included, the function uses the primary stream used by getc().
Returns:
0 (or FALSE) if getc() will need to wait for a character to come in, 1 (or TRUE) if
a character is ready for getc()
Function:
If the RS232 is under software control this function returns TRUE if the start bit
of a character is being sent on the RS232 RCV pin. If the RS232 is hardware
this function returns TRUE if a character has been received and is waiting in the
hardware buffer for getc() to read. This function may be used to poll for data
without stopping and waiting for the data to appear. Note that in the case of
software RS232 this function should be called at least 10 times the bit rate to
ensure incoming data is not lost.
Availability:
All devices.
Requires:
#use rs232
Examples:
char timed_getc() {
long timeout;
timeout_error=FALSE;
timeout=0;
while(!kbhit()&&(++timeout<50000)) // 1/2
// second
delay_us(10);
if(kbhit())
return(getc());
else {
timeout_error=TRUE;
return(0);
}
}
Example Files:
ex_tgetc.c
Also See:
getc(), #USE RS232, RS232 I/O overview
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label_address( )
Syntax:
value = label_address(label);
Parameters:
label is a C label anywhere in the function
Returns:
A 16 bit int in PCB,PCM and a 32 bit int for PCH
Function:
This function obtains the address in ROM of the next instruction after the label.
This is not a normally used function except in very special situations.
Availability:
All devices.
Requires:
Examples:
Nothing
Example Files:
setjmp.h
Also See:
goto_address()
start:
a = (b+c)<<2;
end:
printf("It takes %lu ROM locations.\r\n",
label_address(end)-label_address(start));
labs( )
Syntax:
result = labs (value)
Parameters:
value is a 16 bit signed long int
Returns:
A 16 bit signed long int
Function:
Computes the absolute value of a long integer.
Availability:
Requires:
All devices.
#include
Examples:
if(labs( target_value - actual_value ) > 500)
printf("Error is over 500 points\r\n");
Example Files:
Also See:
None
abs()
180
Built-in-Functions
lcd_load( )
Syntax:
lcd_load (buffer_pointer, offset, length);
Parameters:
buffer_pointer points to the user data to send to the LCD, offset is the offset
into the LCD segment memory to write the data, length is the number of bytes
to transfer.
Returns:
Function:
undefined
Will load length bytes from buffer_pointer into the 923/924 LCD segment data
area beginning at offset (0-15). lcd_symbol provides an easier way to write
data to the segment memory.
Availability:
This function is only available on devices with LCD drive hardware.
Requires
Constants are defined in the devices .h file.
Examples:
lcd_load(buffer, 0, 16);
Example Files:
ex_92lcd.c
Also See:
lcd_symbol(), setup_lcd(), Internal LCD overview
lcd_symbol( )
Syntax:
lcd_symbol (symbol, bx_addr[, by_addr]);
Parameters:
symbol is a 8 bit or 16 bit constant.
bX_addr is a bit address representing the segment location to be used for bit X
of symbol.
1-16 segments could be specified.
Returns:
Function:
undefined
Loads bits into the segment data area for the LCD with each bit address
specified. If bit 0 in symbol is set the segment at B0_addr is set, otherwise it is
cleared. The same is true of all other bits in symbol. The B0_addr is a bit
address into the LCD RAM.
Availability:
This function is only available on devices with LCD drive hardware.
Requires
Examples:
Constants are defined in the devices .h file.
byte CONST DIGIT_MAP[10]=
{0X90,0XB7,0X19,0X36,0X54,0X50,0XB5,0X24};
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C Compiler Reference Manual August 2009
#define DIGIT_1_CONFIG
COM0+2,COM0+4,COM0+5,COM2+4,COM2+1,
COM1+4,COM1+5
for(i=1; i<=9; ++i) {
LCD_SYMBOL(DIGIT_MAP[i],DIGIT_1_CONFIG);
delay_ms(1000);
}
Example Files:
ex_92lcd.c
Also See:
setup_lcd(), lcd_load(), Internal LCD Overview
ldexp( )
Syntax:
result= ldexp (value, exp);
Parameters:
value is float
exp is a signed int.
Returns:
result is a float with value result times 2 raised to power exp.
Function:
The ldexp function multiplies a floating-point number by an integral power of 2.
Availability:
All devices.
Requires:
#include
Examples:
float result;
result=ldexp(.5,0);
// result is .5
Example Files:
None
Also See:
frexp(), exp(), log(), log10(), modf()
182
Built-in-Functions
log( )
Syntax:
result = log (value)
Parameters:
value is a float
Returns:
A float
Function:
Computes the natural logarithm of the float x. If the argument is less than or
equal to zero or too large, the behavior is undefined.
Note on error handling:
"errno.h" is included then the domain and range errors are stored in the errno
variable. The user can check the errno to see if an error has occurred and print
the error using the perror function.
Domain error occurs in the following cases:
• log: when the argument is negative
Availability:
All devices
Requires:
#include
Examples:
lnx = log(x);
Example Files:
Also See:
None
log10(), exp(), pow()
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log10( )
Syntax:
result = log10 (value)
Parameters:
value is a float
Returns:
A float
Function:
Computes the base-ten logarithm of the float x. If the argument is less than or
equal to zero or too large, the behavior is undefined.
Note on error handling:
If "errno.h" is included then the domain and range errors are stored in the errno
variable. The user can check the errno to see if an error has occurred and print
the error using the perror function.
Domain error occurs in the following cases:
• log10: when the argument is negative
Availability:
Requires:
Examples:
Example Files:
Also See:
All devices
#include
db = log10( read_adc()*(5.0/255) )*10;
None
log(), exp(), pow()
longjmp( )
Syntax:
longjmp (env, val)
Parameters:
env: The data object that will be restored by this function
val: The value that the function setjmp will return. If val is 0 then the function
setjmp will return 1 instead.
Returns:
After longjmp is completed, program execution continues as if the
corresponding invocation of the setjmp function had just returned the value
specified by val.
Function:
Performs the non-local transfer of control.
Availability:
Requires:
Examples:
Example Files:
Also See:
All device
#include
184
longjmp(jmpbuf, 1);
None
setjmp()
Built-in-Functions
make8( )
Syntax:
i8 = MAKE8(var, offset)
Parameters:
var is a 16 or 32 bit integer.
offset is a byte offset of 0,1,2 or 3.
Returns:
An 8 bit integer
Function:
Extracts the byte at offset from var. Same as: i8 = (((var >> (offset*8)) & 0xff)
except it is done with a single byte move.
Availability:
Requires:
Examples:
All devices
Nothing
int32 x;
int y;
y = make8(x,3);
Example Files:
Also See:
// Gets MSB of x
None
make16(), make32()
make16( )
Syntax:
i16 = MAKE16(varhigh, varlow)
Parameters:
varhigh and varlow are 8 bit integers.
Returns:
A 16 bit integer
Function:
Makes a 16 bit number out of two 8 bit numbers. If either parameter is 16 or 32
bits only the lsb is used. Same as: i16 =
(int16)(varhigh&0xff)*0x100+(varlow&0xff) except it is done with two byte
moves.
Availability:
Requires:
Examples:
All devices
Nothing
long x;
int hi,lo;
x = make16(hi,lo);
Example Files:
Also See:
ltc1298.c
make8(), make32()
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make32( )
Syntax:
i32 = MAKE32(var1, var2, var3, var4)
Parameters:
var1-4 are a 8 or 16 bit integers. var2-4 are optional.
Returns:
A 32 bit integer
Function:
Makes a 32 bit number out of any combination of 8 and 16 bit numbers. Note
that the number of parameters may be 1 to 4. The msb is first. If the total bits
provided is less than 32 then zeros are added at the msb.
Availability:
All devices
Requires:
Nothing
Examples:
int32 x;
int y;
long z;
x = make32(1,2,3,4);
// x is 0x01020304
y=0x12;
z=0x4321;
x = make32(y,z);
// x is 0x00124321
x = make32(y,y,z);
Example Files:
ex_freqc.c
Also See:
make8(), make16()
186
// x is 0x12124321
Built-in-Functions
malloc( )
Syntax:
ptr=malloc(size)
Parameters:
size is an integer representing the number of byes to be allocated.
Returns:
A pointer to the allocated memory, if any. Returns null otherwise.
Function:
The malloc function allocates space for an object whose size is specified by
size and whose value is indeterminate.
Availability:
Requires:
All devices
#include
Examples:
int * iptr;
iptr=malloc(10);
// iptr will point to a block of memory of 10 bytes.
Example Files:
Also See:
None
realloc(), free(), calloc()
memcpy( )
memmove( )
Syntax:
memcpy (destination, source, n)
memmove(destination, source, n)
Parameters:
destination is a pointer to the destination memory, source is a pointer to the
source memory, n is the number of bytes to transfer
Returns:
Function:
undefined
Copies n bytes from source to destination in RAM. Be aware that array names
are pointers where other variable names and structure names are not (and
therefore need a & before them).
Memmove performs a safe copy (overlapping objects doesn't cause a problem).
Copying takes place as if the n characters from the source are first copied into
a temporary array of n characters that doesn't overlap the destination and
source objects. Then the n characters from the temporary array are copied to
destination.
Availability:
Requires:
All devices
Nothing
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Examples:
memcpy(&structA, &structB, sizeof (structA));
memcpy(arrayA,arrayB,sizeof (arrayA));
memcpy(&structA, &databyte, 1);
char a[20]="hello";
memmove(a,a+2,5);
// a is now "llo"MEMMOVE()
Example Files:
None
Also See:
strcpy(), memset()
memset( )
Syntax:
memset (destination, value, n)
Parameters:
destination is a pointer to memory, value is a 8 bit int, n is a 16 bit int.
On PCB and PCM parts n can only be 1-255.
Returns:
Undefined
Function:
Sets n number of bytes, starting at destination, to value. Be aware that array
names are pointers where other variable names and structure names are not
(and therefore need a & before them).
Availability:
All devices
Requires:
Nothing
Examples:
memset(arrayA, 0, sizeof(arrayA));
memset(arrayB, '?', sizeof(arrayB));
memset(&structA, 0xFF, sizeof(structA));
Example Files:
None
Also See:
memcpy()
188
Built-in-Functions
modf( )
Syntax:
result= modf (value, & integral)
Parameters:
value is a float
integral is a float
Returns:
result is a float
Function:
The modf function breaks the argument value into integral and fractional parts,
each of which has the same sign as the argument. It stores the integral part as
a float in the object integral.
Availability:
Requires:
All devices
#include
Examples:
float result, integral;
result=modf(123.987,&integral);
// result is .987 and integral is 123.0000
Example Files:
Also See:
None
None
_mul( )
Syntax:
prod=_mul(val1, val2);
Parameters:
val1 and val2 are both 8-bit or 16-bit integers
Returns:
A 16-bit integer if both parameters are 8-bit integers, or a 32-bit integer if both
parameters are 16-bit integers.
Function:
Performs an optimized multiplication. By accepting a different type than it returns,
this function avoids the overhead of converting the parameters to a larger type.
Availability:
Requires:
Examples:
All devices
Nothing
Example Files:
Also See:
int a=50, b=100;
long int c;
c = _mul(a, b);
//c holds 5000
None
None
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nargs( )
Syntax:
Void foo(char * str, int count, ...)
Parameters:
The function can take variable parameters. The user can use stdarg library to
create functions that take variable parameters.
Returns:
Function dependent.
Function:
The stdarg library allows the user to create functions that supports variable
arguments.
The function that will accept a variable number of arguments must have at least
one actual, known parameters, and it may have more.The number of
arguments is often passed to the function in one of its actual parameters. If the
variable-length argument list can involve more that one type, the type
information is generally passed as well. Before processing can begin, the
function creates a special argument pointer of type va_list.
Availability:
All devices
Requires:
#include
Examples:
int foo(int num, ...)
{
int sum = 0;
int i;
va_list argptr; // create special argument pointer
va_start(argptr,num); // initialize argptr
for(i=0; i
Examples:
struct
time_structure {
int hour, min, sec;
int zone : 4;
intl daylight_savings;
}
x = offsetof(time_structure, sec);
// x will be 2
x = offsetofbit(time_structure, sec);
// x will be 16
x = offsetof (time_structure,
daylight_savings);
// x will be 3
x = offsetofbit(time_structure,
daylight_savings);
// x will be 28
Example Files:
None
Also See:
None
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output_x( )
Syntax:
output_a (value)
output_b (value)
output_c (value)
output_d (value)
output_e (value)
output_f (value)
output_g (value)
output_h (value)
output_j (value)
output_k (value)
Parameters:
value is a 8 bit int
Returns:
undefined
Function:
Output an entire byte to a port. The direction register is changed in accordance
with the last specified #USE *_IO directive.
Availability:
All devices, however not all devices have all ports (A-E)
Requires:
Nothing
Examples:
OUTPUT_B(0xf0);
Example Files:
ex_patg.c
Also See:
input(), output_low(), output_high(), output_float(), output_bit(), #use fixed_io,
#use fast_io, #use standard_io, General Purpose I/O
192
Built-in-Functions
output_bit( )
Syntax:
output_bit (pin, value)
Parameters:
Pins are defined in the devices .h file. The actual number is a bit address. For
example, port a (byte 5) bit 3 would have a value of 5*8+3 or 43. This is
defined as follows: #define PIN_A3 43. The PIN could also be a variable. The
variable must have a value equal to one of the constants (like PIN_A1) to work
properly. The tristate register is updated unless the FAST_I0 mode is set on
port A. Note that doing I/0 with a variable instead of a constant will take much
longer time. Value is a 1 or a 0.
Returns:
undefined
Function:
Outputs the specified value (0 or 1) to the specified I/O pin. The method of
setting the direction register is determined by the last #USE *_IO
directive.
Availability:
All devices.
Requires:
Pin constants are defined in the devices .h file
Examples:
output_bit( PIN_B0, 0);
// Same as output_low(pin_B0);
output_bit( PIN_B0,input( PIN_B1 ) );
// Make pin B0 the same as B1
output_bit( PIN_B0,
shift_left(&data,1,input(PIN_B1)));
// Output the MSB of data to
// B0 and at the same time
// shift B1 into the LSB of data
int16 i=PIN_B0;
ouput_bit(i,shift_left(&data,1,input(PIN_B1)));
//same as above example, but
//uses a variable instead of a constant
Example Files:
ex_extee.c with 9356.c
Also See:
input(), output_low(), output_high(), output_float(), output_x(), #use fixed_io,
#use fast_io, #use standard_io, General Purpose I/O
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output_drive( )
Syntax:
output_drive(pin)
Parameters:
Pins are defined in the devices .h file. The actual value is a bit address. For
example, port a (byte 5) bit 3 would have a value of 5*8+3 or 43. This is defined
as follows: #define PIN_A3 43.
Returns:
Function:
Availability:
Requires:
Examples:
undefined
Sets the specified pin to the output mode.
All devices.
Pin constants are defined in the devices.h file.
Example Files:
Also See:
None
input(), output_low(), output_high(), output_bit(), output_x(), output_float()
output_drive(pin_A0); // sets pin_A0 to output its value
output_bit(pin_B0, input(pin_A0)) // makes B0 the same as A0
output_float( )
Syntax:
output_float (pin)
Parameters:
Pins are defined in the devices .h file. The actual value is a bit address. For
example, port a (byte 5) bit 3 would have a value of 5*8+3 or 43. This is
defined as follows: #define PIN_A3 43. The PIN could also be a variable to
identify the pin. The variable must have a value equal to one of the constants
(like PIN_A1) to work properly. Note that doing I/0 with a variable instead of a
constant will take much longer time.
Returns:
Function:
undefined
Sets the specified pin to the input mode. This will allow the pin to float high to
represent a high on an open collector type of connection.
Availability:
Requires:
Examples:
All devices
Pin constants are defined in the devices .h file
Example Files:
Also See:
None
input(), output_low(), output_high(), output_bit(), output_x(), output_drive(),
#use fixed_io, #use fast_io, #use standard_io, General Purpose I/O
194
if( (data & 0x80)==0 )
output_low(pin_A0);
else
output_float(pin_A0);
Built-in-Functions
output_high( )
Syntax:
output_high (pin)
Parameters:
Pin to write to. Pins are defined in the devices .h file. The actual value is a bit
address. For example, port a (byte 5) bit 3 would have a value of 5*8+3 or 43.
This is defined as follows: #define PIN_A3 43. The PIN could also be a
variable. The variable must have a value equal to one of the constants (like
PIN_A1) to work properly. The tristate register is updated unless the FAST_I0
mode is set on port A. Note that doing I/0 with a variable instead of a constant
will take much longer time.
Returns:
undefined
Function:
Sets a given pin to the high state. The method of I/O used is dependent on the
last USE *_IO directive.
Availability:
All devices.
Requires:
Pin constants are defined in the devices .h file
Examples:
output_high(PIN_A0);
Int16 i=PIN_A1;
output_low(PIN_A1);
Example Files:
ex_sqw.c
Also See:
input(), output_low(), output_float(), output_bit(), output_x(), #use fixed_io, #use
fast_io, #use standard_io, General Purpose I/O
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output_low( )
Syntax:
output_low (pin)
Parameters:
Pins are defined in the devices .h file. The actual value is a bit address. For
example, port a (byte 5) bit 3 would have a value of 5*8+3 or 43. This is defined
as follows: #define PIN_A3 43. The PIN could also be a variable. The variable
must have a value equal to one of the constants (like PIN_A1) to work properly.
The tristate register is updated unless the FAST_I0 mode is set on port A. Note
that doing I/0 with a variable instead of a constant will take much longer time.
Returns:
Function:
undefined
Sets a given pin to the ground state. The method of I/O used is dependent on
the last USE *_IO directive.
Availability:
Requires:
Examples:
All devices.
Pin constants are defined in the devices .h file
output_low(PIN_A0);
Int16i=PIN_A1;
output_low(PIN_A1);
Example Files:
ex_sqw.c
Also See:
input(), output_high(), output_float(), output_bit(), output_x(), #use fixed_io,
#use fast_io, #use standard_io, General Purpose I/O
output_toggle( )
Syntax:
output_toggle(pin)
Parameters:
Pins are defined in the devices .h file. The actual value is a bit address. For
example, port a (byte 5) bit 3 would have a value of 5*8+3 or 43. This is
defined as follows: #define PIN_A3 43.
Returns:
Function:
Undefined
Toggles the high/low state of the specified pin.
Availability:
Requires:
Examples:
All devices.
Pin constants are defined in the devices .h file
Example Files:
Also See:
None
Input(), output_high(), output_low(), output_bit(), output_x()
196
output_toggle(PIN_B4);
Built-in-Functions
perror( )
Syntax:
perror(string);
Parameters:
string is a constant string or array of characters (null terminated).
Returns:
Nothing
Function:
This function prints out to STDERR the supplied string and a description of the
last system error (usually a math error).
Availability:
All devices.
Requires:
#use rs232, #include
Examples:
x = sin(y);
if(errno!=0)
perror("Problem in find_area");
Example Files:
Also See:
None
RS232 I/O overview
port_x_pullups ( )
Syntax:
port_a_pullups (value)
port_b_pullups (value)
port_d_pullups (value)
port_e_pullups (value)
port_j_pullups (value)
port_x_pullups (upmask)
port_x_pullups (upmask, downmask)
Parameters:
value is TRUE or FALSE on most parts, some parts that allow pullups to be
specified on individual pins permit an 8 bit int here, one bit for each port pin.
upmask for ports that permit pullups to be specified on a pin basis. This mask
indicates what pins should have pullups activated. A 1 indicates the pullups is on.
downmask for ports that permit pulldowns to be specified on a pin basis. This
mask indicates what pins should have pulldowns activated. A 1 indicates the
pulldowns is on.
Returns:
undefined
Function:
Sets the input pullups. TRUE will activate, and a FALSE will deactivate.
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Availability:
Only 14 and 16 bit devices (PCM and PCH). (Note: use SETUP_COUNTERS
on PCB parts).
Requires:
Nothing
Examples:
port_a_pullups(FALSE);
Example Files:
ex_lcdkb.c , kbd.c
Also See:
input(), input_x(), output_float()
pow( )
pwr( )
Syntax:
f = pow (x,y)
f = pwr (x,y)
Parameters:
x and y are of type float
Returns:
A float
Function:
Calculates X to the Y power.
Note on error handling:
If "errno.h" is included then the domain and range errors are stored in the errno
variable. The user can check the errno to see if an error has occurred and print
the error using the perror function.
Range error occurs in the following case:
• pow: when the argument X is negative
Availability:
All Devices
Requires:
#include
Examples:
area = pow (size,3.0);
Example Files:
None
Also See:
None
198
Built-in-Functions
printf( )
fprintf( )
Syntax:
printf (string)
or
printf (cstring, values...)
or
printf (fname, cstring, values...)
fprintf (stream, cstring, values...)
Parameters:
String is a constant string or an array of characters null terminated. Values is a list of
variables separated by commas, fname is a function name to be used for outputting
(default is putc is none is specified). Stream is a stream identifier (a constant byte)
undefined
Outputs a string of characters to either the standard RS-232 pins (first two
forms) or to a specified function. Formatting is in accordance with the string
argument. When variables are used this string must be a constant. The %
character is used within the string to indicate a variable value is to be formatted
and output. Longs in the printf may be 16 or 32 bit. A %% will output a single
%. Formatting rules for the % follows.
Returns:
Function:
If fprintf() is used then the specified stream is used where printf() defaults to
STDOUT (the last USE RS232).
Format:
The format takes the generic form %nt. n is optional and may be 1-9 to specify how
many characters are to be outputted, or 01-09 to indicate leading zeros, or 1.1 to
9.9 for floating point and %w output. t is the type and may be one of the following:
c
Character
s
String or character
u
Unsigned int
d
Signed int
Lu
Long unsigned int
Ld
Long signed int
x
Hex int (lower case)
X
Hex int (upper case)
Lx
Hex long int (lower case)
LX
Hex long int (upper case)
f
Float with truncated decimal
g
Float with rounded decimal
e
Float in exponential format
w
Unsigned int with decimal place inserted. Specify two numbers for
n. The first is a total field width. The second is the desired number
of decimal places.
Example formats:
Specifier
Value=0x12
Value=0xfe
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%03u
018
%u
18
%2u
18
%5
18
%d
18
%x
12
%X
12
%4X
0012
%3.1w
1.8
* Result is undefined - Assume garbage.
254
254
*
254
-2
fe
FE
00FE
25.4
Availability:
All Devices
Requires:
#use rs232 (unless fname is used)
Examples:
byte x,y,z;
printf("HiThere");
printf("RTCCValue=>%2x\n\r",get_rtcc());
printf("%2u %X %4X\n\r",x,y,z);
printf(LCD_PUTC, "n=%u",n);
Example Files:
ex_admm.c , ex_lcdkb.c
Also See:
atoi(), puts(), putc(), getc() (for a stream example), RS232 I/O overview
200
Built-in-Functions
psp_output_full( )
psp_input_full( )
psp_overflow( )
Syntax:
result = psp_output_full()
result = psp_input_full()
result = psp_overflow()
Parameters:
None
Returns:
A 0 (FALSE) or 1 (TRUE)
Function:
These functions check the Parallel Slave Port (PSP) for the indicated conditions
and return TRUE or FALSE.
Availability:
This function is only available on devices with PSP hardware on chips.
Requires:
Nothing
Examples:
while (psp_output_full()) ;
psp_data = command;
while(!psp_input_full()) ;
if ( psp_overflow() )
error = TRUE;
else
data = psp_data;
Example Files:
ex_psp.c
Also See:
setup_psp(), PSP overview
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putc( )
putchar( )
fputc( )
Syntax:
putc (cdata)
putchar (cdata)
fputc(cdata, stream)
Parameters:
cdata is a 8 bit character. Stream is a stream identifier (a constant byte)
Returns:
undefined
Function:
This function sends a character over the RS232 XMIT pin. A #USE RS232
must appear before this call to determine the baud rate and pin used. The
#USE RS232 remains in effect until another is encountered in the file.
If fputc() is used then the specified stream is used where putc() defaults to
STDOUT (the last USE RS232).
Availability:
All devices
Requires:
#use rs232
Examples:
putc('*');
for(i=0; i<10; i++)
putc(buffer[i]);
putc(13);
Example Files:
ex_tgetc.c
Also See:
getc(), printf(), #USE RS232, RS232 I/O overview
202
Built-in-Functions
puts( )
fputs( )
Syntax:
puts (string).
fputs (string, stream)
Parameters:
string is a constant string or a character array (null-terminated). Stream is a
stream identifier (a constant byte)
Returns:
undefined
Function:
Sends each character in the string out the RS232 pin using PUTC(). After the
string is sent a RETURN (13) and LINE-FEED (10) are sent. In general printf()
is more useful than puts().
If fputs() is used then the specified stream is used where puts() defaults to
STDOUT (the last USE RS232)
Availability:
All devices
Requires:
#use rs232
Examples:
puts( " ----------- " );
puts( " |
HI
| " );
puts( " ----------- " );
Example Files:
None
Also See:
printf(), gets(), RS232 I/O overview
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qsort( )
Syntax:
qsort (base, num, width, compare)
Parameters:
base: Pointer to array of sort data
num: Number of elements
width: Width of elements
compare: Function that compares two elements
Returns:
None
Function:
Performs the shell-metzner sort (not the quick sort algorithm). The contents of
the array are sorted into ascending order according to a comparison function
pointed to by compare.
Availability:
All devices
Requires:
#include
Examples:
int nums[5]={ 2,3,1,5,4};
int compar(void *arg1,void *arg2);
void main() {
qsort ( nums, 5, sizeof(int), compar);
}
int compar(void *arg1,void *arg2) {
if ( * (int *) arg1 < ( * (int *) arg2) return –1
else if ( * (int *) arg1 == ( * (int *) arg2) return 0
else return 1;
}
Example Files:
ex_qsort.c
Also See:
bsearch()
204
Built-in-Functions
rand( )
Syntax:
re=rand()
Parameters:
Returns:
None
A pseudo-random integer.
Function:
The rand function returns a sequence of pseudo-random integers in the range
of 0 to RAND_MAX.
Availability:
All devices
Requires:
#include
Examples:
int I;
I=rand();
Example Files:
Also See:
None
srand()
read_adc( )
Syntax:
value = read_adc ([mode])
Parameters:
mode is an optional parameter. If used the values may be:
ADC_START_AND_READ (continually takes readings, this is the default)
ADC_START_ONLY (starts the conversion and returns)
ADC_READ_ONLY (reads last conversion result)
Returns:
Either a 8 or 16 bit int depending on #DEVICE ADC= directive.
Function:
This function will read the digital value from the analog to digital converter. Calls
to setup_adc(), setup_adc_ports() and set_adc_channel() should be made
sometime before this function is called. The range of the return value depends
on number of bits in the chips A/D converter and the setting in the #DEVICE
ADC= directive as follows:
#DEVICE
8 bit
10 bit
11 bit
12 bit
16 bit
ADC=8
00-FF 00-FF
00-FF
00-FF
00-FF
ADC=10
x
0-3FF
x
0-3FF
x
ADC=11
x
x
0-7FF
x
x
ADC=16
0-FF00 0-FFC0
0-FFEO
0-FFF0
0-FFFF
Note: x is not defined
This function is only available on devices with A/D hardware.
Availability:
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C Compiler Reference Manual August 2009
Requires:
Pin constants are defined in the devices .h file.
Examples:
setup_adc( ADC_CLOCK_INTERNAL );
setup_adc_ports( ALL_ANALOG );
set_adc_channel(1);
while ( input(PIN_B0) ) {
delay_ms( 5000 );
value = read_adc();
printf("A/D value = %2x\n\r", value);
}
read_adc(ADC_START_ONLY);
sleep();
value=read_adc(ADC_READ_ONLY);
Example Files:
ex_admm.c, ex_14kad.c
Also See:
setup_adc(), set_adc_channel(), setup_adc_ports(), #DEVICE, ADC overview
read_bank( )
Syntax:
value = read_bank (bank, offset)
Parameters:
bank is the physical RAM bank 1-3 (depending on the device), offset is the
offset into user RAM for that bank (starts at 0),
Returns:
8 bit int
Function:
Read a data byte from the user RAM area of the specified memory bank. This
function may be used on some devices where full RAM access by auto
variables is not efficient. For example, setting the pointer size to 5 bits on the
PIC16C57 chip will generate the most efficient ROM code. However, auto
variables can not be about 1Fh. Instead of going to 8 bit pointers, you can save
ROM by using this function to read from the hard-to-reach banks. In this case,
the bank may be 1-3 and the offset may be 0-15.
Availability:
All devices but only useful on PCB parts with memory over 1Fh
and PCM parts with memory over FFh.
Requires:
Examples:
Nothing
206
// See write_bank() example to see
// how we got the data
// Moves data from buffer to LCD
i=0;
Built-in-Functions
do {
c=read_bank(1,i++);
if(c!=0x13)
lcd_putc(c);
} while (c!=0x13);
Example Files:
ex_psp.c
Also See:
write_bank(), and the "Common Questions and Answers" section for more
information.
read_calibration( )
Syntax:
value = read_calibration (n)
Parameters:
n is an offset into calibration memory beginning at 0
Returns:
An 8 bit byte
Function:
The read_calibration function reads location "n" of the 14000-calibration
memory.
Availability:
This function is only available on the PIC14000.
Requires:
Nothing
Examples:
fin = read_calibration(16);
Example Files:
ex_14kad.c with 14kcal.c
Also See:
None
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C Compiler Reference Manual August 2009
read_configuration_memory( )
Syntax:
read_configuration_memory(ramPtr, n)
Parameters:
ramPtr is the destination pointer for the read results
count is an 8 bit integer
Returns:
undefined
Function:
Reads n bytes of configuration memory and saves the values to ramPtr.
Availability:
Requires:
Examples:
All
Nothing
Example Files:
Also See:
None
write_configuration_memory(), read_program_memory(),
Configuration Memory Overview
int data[6];
read_configuration_memory(data,6);
read_eeprom( )
Syntax:
value = read_eeprom (address)
Parameters:
address is an (8 bit or 16 bit depending on the part) int
Returns:
An 8 bit int
Function:
Reads a byte from the specified data EEPROM address. The address begins
at 0 and the range depends on the part.
Availability:
This command is only for parts with built-in EEPROMS
Requires:
Nothing
Examples:
#define LAST_VOLUME 10
volume = read_EEPROM (LAST_VOLUME);
Example Files:
Also See:
None
write_eeprom(), data eeprom overview
208
Built-in-Functions
read_program_eeprom( )
Syntax:
value = read_program_eeprom (address)
Parameters:
address is 16 bits on PCM parts and 32 bits on PCH parts
Returns:
16 bits
Function:
Reads data from the program memory.
Availability:
Only devices that allow reads from program memory.
Requires:
Examples:
Nothing
Example Files:
Also See:
None
write_program_eeprom(), write_eeprom(), read_eeprom(), Program eeprom overview
checksum = 0;
for(i=0;i<8196;i++)
checksum^=read_program_eeprom(i);
printf("Checksum is %2X\r\n",checksum);
read_program_memory( )
read_external_memory( )
Syntax:
READ_PROGRAM_MEMORY (address, dataptr, count );
READ_EXTERNAL_MEMORY (address, dataptr, count );
Parameters:
address is 16 bits on PCM parts and 32 bits on PCH parts. The least
significant bit should always be 0 in PCM.
dataptr is a pointer to one or more bytes.
count is a 8 bit integer
Returns:
Function:
undefined
Reads count bytes from program memory at address to RAM at dataptr. Both
of these functions operate exactly the same.
Availability:
Only devices that allow reads from program memory.
Requires:
Examples:
Nothing
Example Files:
Also See:
None
write program memory ( ), External memory overview, Program eeprom overview
char buffer[64];
read_external_memory(0x40000, buffer, 64);
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realloc( )
Syntax:
realloc (ptr, size)
Parameters:
ptr is a null pointer or a pointer previously returned by calloc or malloc or realloc
function, size is an integer representing the number of byes to be allocated.
Returns:
A pointer to the possibly moved allocated memory, if any. Returns null
otherwise.
Function:
The realloc function changes the size of the object pointed to by the ptr to the size
specified by the size. The contents of the object shall be unchanged up to the
lesser of new and old sizes. If the new size is larger, the value of the newly
allocated space is indeterminate. If ptr is a null pointer, the realloc function
behaves like malloc function for the specified size. If the ptr does not match a
pointer earlier returned by the calloc, malloc or realloc, or if the space has been
deallocated by a call to free or realloc function, the behavior is undefined. If the
space cannot be allocated, the object pointed to by ptr is unchanged. If size is
zero and the ptr is not a null pointer, the object is to be freed.
Availability:
All devices
Requires:
#include
Examples:
int * iptr;
iptr=malloc(10);
realloc(iptr,20)
// iptr will point to a block of memory of 20 bytes, if
available.
Example Files:
None
Also See:
malloc(), free(), calloc()
210
Built-in-Functions
reset_cpu( )
Syntax:
reset_cpu()
Parameters:
Returns:
None
This function never returns
Function:
This is a general purpose device reset. It will jump to location 0 on PCB and
PCM parts and also reset the registers to power-up state on the PIC18XXX.
Availability:
Requires:
Examples:
All devices
Nothing
Example Files:
Also See:
None
None
if(checksum!=0)
reset_cpu();
restart_cause( )
Syntax:
value = restart_cause()
Parameters:
Returns:
None
A value indicating the cause of the last processor reset. The actual values are
device dependent. See the device .h file for specific values for a specific
device. Some example values are: WDT_FROM_SLEEP, WDT_TIMEOUT,
MCLR_FROM_SLEEP and NORMAL_POWER_UP.
Function:
Returns the cause of the last processor reset.
Availability:
Requires:
All devices
Constants are defined in the devices .h file.
Examples:
switch ( restart_cause() ) {
case WDT_FROM_SLEEP:
case WDT_TIMEOUT:
handle_error();
}
Example Files:
ex_wdt.c
Also See:
restart_wdt(), reset_cpu()
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restart_wdt( )
Syntax:
restart_wdt()
Parameters:
None
Returns:
undefined
Function:
Restarts the watchdog timer. If the watchdog timer is enabled, this must be
called periodically to prevent the processor from resetting.
The watchdog timer is used to cause a hardware reset if the software appears
to be stuck.
The timer must be enabled, the timeout time set and software must periodically
restart the timer. These are done differently on the PCB/PCM and PCH parts
as follows:
Enable/Disable
Timeout time
restart
Availability:
All devices
Requires:
#fuses
Examples:
#fuses WDT
PCB/PCM
#fuses
setup_wdt()
restart_wdt()
PCH
setup_wdt()
#fuses
restart_wdt()
// PCB/PCM example
// See setup_wdt for a PIC18 example
main() {
setup_wdt(WDT_2304MS);
while (TRUE) {
restart_wdt();
perform_activity();
}
}
Example Files:
ex_wdt.c
Also See:
#fuses, setup_wdt(), WDT or Watch Dog Timer overview
212
Built-in-Functions
rotate_left( )
Syntax:
rotate_left (address, bytes)
Parameters:
address is a pointer to memory, bytes is a count of the number of bytes to work with.
Returns:
Function:
undefined
Rotates a bit through an array or structure. The address may be an array
identifier or an address to a byte or structure (such as &data). Bit 0 of the
lowest BYTE in RAM is considered the LSB.
All devices
Nothing
Availability:
Requires:
Examples:
Example Files:
Also See:
x = 0x86;
rotate_left( &x, 1);
// x is now 0x0d
None
rotate_right(), shift_left(), shift_right()
rotate_right( )
Syntax:
rotate_right (address, bytes)
Parameters:
address is a pointer to memory, bytes is a count of the number of bytes to work with.
Returns:
Function:
undefined
Rotates a bit through an array or structure. The address may be an array
identifier or an address to a byte or structure (such as &data). Bit 0 of the
lowest BYTE in RAM is considered the LSB.
Availability:
Requires:
Examples:
All devices
Nothing
Example Files:
Also See:
struct {
int cell_1
int cell_2
int cell_3
int cell_4
rotate_right(
rotate_right(
rotate_right(
rotate_right(
// cell_1->4,
: 4;
: 4;
: 4;
: 4; } cells;
&cells, 2);
&cells, 2);
&cells, 2);
&cells, 2);
2->1, 3->2 and 4-> 3
None
rotate_left(), shift_left(), shift_right()
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rtos_await( )
The RTOS is only included in the PCW, PCWH and PCWHD software packages.
Syntax:
rtos_await (expre)
Parameters:
expre is a logical expression.
Returns:
None
Function:
This function can only be used in an RTOS task. This function waits for expre to
be true before continuing execution of the rest of the code of the RTOS task. This
function allows other tasks to execute while the task waits for expre to be true.
Availability:
All devices
Requires:
#use rtos
Examples:
rtos_await(kbhit());
Also See:
None
rtos_disable( )
The RTOS is only included in the PCW, PCWH and PCWHD software packages.
Syntax:
rtos_disable (task)
Parameters:
task is the identifier of a function that is being used as an RTOS task.
Returns:
None
Function:
This function disables a task which causes the task to not execute until enabled
by RTOS_ENABLE. All tasks are enabled by default.
Availability:
All devices
Requires:
#use rtos
Examples:
rtos_disable(toggle_green)
Also See:
rtos enable()
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Built-in-Functions
rtos_enable( )
The RTOS is only included in the PCW, PCWH and PCWHD software packages.
Syntax:
rtos_enable (task)
Parameters:
task is the identifier of a function that is being used as an RTOS task.
Returns:
None
Function:
This function enables a task to execute at it's specified rate. All tasks are enabled
by default.
Availability:
All devices
Requires:
#use rtos
Examples:
rtos_enable(toggle_green);
Also See:
rtos disable()
rtos_msg_poll( )
The RTOS is only included in the PCW, PCWH and PCWHD software packages.
Syntax:
i = rtos_msg_poll()
Parameters:
None
Returns:
An integer that specifies how many messages are in the queue.
Function:
This function can only be used inside an RTOS task. This function returns the
number of messages that are in the queue for the task that the
RTOS_MSG_POLL function is used in.
Availability:
All devices
Requires:
#use rtos
Examples:
if(rtos_msg_poll())
Also See:
rtos msg send(), rtos msg read()
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rtos_msg_read( )
The RTOS is only included in the PCW, PCWH and PCWHD software packages.
Syntax:
b = rtos_msg_read()
Parameters:
Returns:
None
A byte that is a message for the task.
Function:
This function can only be used inside an RTOS task. This function reads
in the next (message) of the queue for the task that the
RTOS_MSG_READ function is used in.
Availability:
Requires:
All devices
#use rtos
Examples:
if(rtos_msg_poll()) {
b = rtos_msg_read();
Also See:
rtos msg poll(), rtos msg send()
rtos_msg_send( )
The RTOS is only included in the PCW, PCWH and PCWHD software packages.
Syntax:
rtos_msg_send(task, byte)
Parameters:
task is the identifier of a function that is being used as an RTOS task
byte is the byte to send to task as a message.
Returns:
Function:
None
This function can be used anytime after RTOS_RUN() has been called.
This function sends a byte long message (byte) to the task identified by
task.
Availability:
Requires:
All devices
#use rtos
Examples:
if(kbhit())
{
rtos_msg_send(echo, getc());
}
Also See:
rtos_msg_poll(), rtos_msg_read()
216
Built-in-Functions
rtos_overrun( )
The RTOS is only included in the PCW, PCWH and PCWHD software packages.
Syntax:
rtos_overrun([task])
Parameters:
task is an optional parameter that is the identifier of a function that is being used
as an RTOS task
Returns:
A 0 (FALSE) or 1 (TRUE)
Function:
This function returns TRUE if the specified task took more time to execute than it
was allocated. If no task was specified, then it returns TRUE if any task ran over
it's alloted execution time.
Availability:
Requires:
All devices
#use rtos(statistics)
Examples:
rtos_overrun()
Also See:
None
rtos_run( )
The RTOS is only included in the PCW, PCWH and PCWHD software packages.
Syntax:
rtos_run()
Parameters:
Returns:
Function:
None
None
This function begins the execution of all enabled RTOS tasks. (All tasks
are enabled by default.) This function controls the execution of the RTOS
tasks at the allocated rate for each task. This function will return only when
RTOS_TERMINATE() is called.
Availability:
Requires:
All devices
#USE RTOS
Examples:
rtos_run()
Also See:
rtos terminate()
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rtos_signal( )
The RTOS is only included in the PCW, PCWH and PCWHD software packages.
Syntax:
rtos_signal (sem)
Parameters:
sem is a global variable that represents the current availability of a shared
system resource (a semaphore).
Returns:
Function:
None
This function can only be used by an RTOS task. This function increments sem to
let waiting tasks know that a shared resource is available for use.
Availability:
Requires:
All devices
#use rtos
Examples:
rtos_signal(uart_use)
Also See:
rtos wait()
rtos_stats( )
The RTOS is only included in the PCW, PCWH and PCWHD software packages.
Syntax:
rtos_stats(task,stat)
Parameters:
Returns:
task is the identifier of a function that is being used as an RTOS task.
stat is one of the following:
rtos_min_time –
minimum processor time needed for one execution of
the specified task
rtos_max_time –
maximum processor time needed for one
execution of the specified task
rtos_total_time –
total processor time used by a task
An int32 representing the us for the specified stat for the specified task.
Function:
This function returns a specified stat for a specified task.
Availability:
Requires:
All devices
#use rtos(statistics)
Examples:
rtos_stats(echo, rtos_total_time)
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Built-in-Functions
rtos_terminate( )
The RTOS is only included in the PCW, PCWH and PCWHD software packages.
Syntax:
rtos_terminate()
Parameters:
Returns:
Function:
None
None
This function ends the execution of all RTOS tasks. The execution of the
program will continue with the first line of code after the RTOS_RUN()
call in the program. (This function causes RTOS_RUN() to return.)
Availability:
Requires:
All devices
#use rtos
Examples:
rtos_terminate()
Also See:
rtos run()
rtos_wait( )
The RTOS is only included in the PCW, PCWH and PCWHD software packages.
Syntax:
rtos_wait (sem)
Parameters:
sem is a global variable that represents the current availability of a shared
system resource (a semaphore).
Returns:
Function:
None
This function can only be used by an RTOS task. This function waits for sem to
be greater than 0 (shared resource is available), then decrements sem to claim
usage of the shared resource and continues the execution of the rest of the code
the RTOS task. This function allows other tasks to execute while the task waits
for the shared resource to be available.
Availability:
Requires:
All devices
#use rtos
Examples:
rtos_wait(uart_use)
Also See:
rtos signal()
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rtos_yield( )
The RTOS is only included in the PCW, PCWH and PCWHD software packages.
Syntax:
Parameters:
Returns:
Function:
rtos_yield()
None
None
This function can only be used in an RTOS task. This function stops the
execution of the current task and returns control of the processor to
RTOS_RUN. When the next task executes, it will start it's execution on
the line of code after the RTOS_YIELD.
Availability:
Requires:
Examples:
All devices
#use rtos
Also See:
None
void yield(void)
{
printf(“Yielding...\r\n”);
rtos_yield();
printf(“Executing code after yield\r\n”);
}
set_adc_channel( )
Syntax:
Parameters:
set_adc_channel (chan)
chan is the channel number to select. Channel numbers start at 0 and are
labeled in the data sheet AN0, AN1
Returns:
Function:
undefined
Specifies the channel to use for the next READ_ADC call. Be aware that you
must wait a short time after changing the channel before you can get a valid
read. The time varies depending on the impedance of the input source. In
general 10us is good for most applications. You need not change the channel
before every read if the channel does not change.
Availability:
Requires:
Examples:
This function is only available on devices with A/D hardware.
Nothing
Example Files:
ex_admm.c
Also See:
read_adc(), setup_adc(), setup_adc_ports(), ADC overview
220
set_adc_channel(2);
delay_us(10);
value = read_adc();
Built-in-Functions
set_adc_channel( )
Syntax:
set_adc_channel (chan)
Parameters:
chan is the channel number to select. Channel numbers start at 0 and are
labeled in the data sheet AN0, AN1
Returns:
Function:
undefined
Specifies the channel to use for the next READ_ADC call. Be aware that you
must wait a short time after changing the channel before you can get a valid
read. The time varies depending on the impedance of the input source. In
general 10us is good for most applications. You need not change the channel
before every read if the channel does not change.
Availability:
This function is only available on devices with A/D hardware.
Requires:
Examples:
Nothing
Example Files:
ex_admm.c
Also See:
read_adc(), setup_adc(), setup_adc_ports(), ADC overview
set_adc_channel(2);
delay_us(10);
value = read_adc();
set_power_pwmx_duty( )
Syntax:
set_power_pwmX_duty(duty)
Parameters:
X is 0, 2, 4, or 6
Duty is an integer between 0 and 16383.
Returns:
Function:
undefined
Stores the value of duty into the appropriate PDCXL/H register. This duty value
is the amount of time that the PWM output is in the active state.
Availability:
All devices equipped with PWM.
Requires:
Examples:
None
Example Files:
Also See:
None
setup_power_pwm(), setup_power_pwm_pins(),set_power_pwm_override()
set_power_pwmx_duty(4000);
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set_power_pwm_override( )
Syntax:
set_power_pwm_override(pwm, override, value)
Parameters:
pwm is a constant between 0 and 7
Override is true or false
Value is 0 or 1
Returns:
undefined
Function:
pwm selects which module will be affected. Override determines whether the
output is to be determined by the OVDCONS register or the PDC registers.
When override is false, the PDC registers determine the output. When
override is true, the output is determined by the value stored in OVDCONS.
When value is a 1, the PWM pin will be driven to its active state on the next
duty cycle. If value is 0, the pin will be inactive.
Availability:
All devices equipped with PWM.
Requires:
None
Examples:
set_power_pwm_override(1, true, 1); //PWM1 will be overridden
to active state
set_power_pwm_override(1, false, 0); //PMW1 will not be
overidden
Example Files:
None
Also See:
setup_power_pwm(), setup_power_pwm_pins(),set_power_pwmX_duty()
222
Built-in-Functions
set_pwm1_duty( )
set_pwm2_duty( )
set_pwm3_duty( )
set_pwm4_duty( )
set_pwm5_duty( )
Syntax:
set_pwm1_duty (value)
set_pwm2_duty (value)
set_pwm3_duty (value)
set_pwm4_duty (value)
set_pwm5_duty (value)
Parameters:
value may be an 8 or 16 bit constant or variable.
Returns:
undefined
Function:
Writes the 10-bit value to the PWM to set the duty. An 8-bit value may be used
if the most significant bits are not required. The 10 bit value is then used to
determine the duty cycle of the PWM signal as follows:
• duty cycle = value / [ 4 * (PR2 +1 ) ]
Where PR2 is the masimum value timer 2 will count to before toggling the
output pin.
Availability:
This function is only available on devices with CCP/PWM hardware.
Requires:
Nothing
Examples:
// For a 20 mhz clock, 1.2 khz frequency,
// t2DIV set to 16, PR2 set to 200
// the following sets the duty to 50% (or 416 us).
long duty;
duty = 408; // [408/(4*(200+1))]=0.5=50%
set_pwm1_duty(duty);
Example Files:
ex_pwm.c
Also See:
setup_ccpX(), CCP1 overview
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set_rtcc( )
set_timer0( )
set_timer1( )
set_timer2( )
set_timer3( )
set_timer4( )
set_timer5( )
Syntax:
set_timer0(value)
set_timer1(value)
set_timer2(value)
set_timer3(value)
set_timer4(value)
set_timer5(value)
Parameters:
Timers 1 & 3 get a 16 bit int.
Timer 2 gets an 8 bit int.
Timer 0 (AKA RTCC) gets an 8 bit int except on the PIC18XXX where it needs
a 16 bit int.
Returns:
undefined
Function:
Sets the count value of a real time clock/counter. RTCC and Timer0 are the
same. All timers count up. When a timer reaches the maximum value it will flip
over to 0 and continue counting (254, 255, 0, 1, 2...)
Availability:
Timer 0 - All devices
Timers 1 & 2 - Most but not all PCM devices
Timer 3 - Only PIC18XXX
Timer 4 - Some PCH devices
Timer 5 - Only PIC18XX31
Requires:
Nothing
Examples:
// 20 mhz clock, no prescaler, set timer 0
// to overflow in 35us
set_timer0(81);
or set_rtcc (value)
// 256-(.000035/(4/20000000))
Example Files:
ex_patg.c
Also See:
set_timer1(), get_timerX() Timer0 overview, Timer1overview, Timer2 overview,
Timer5 overview
224
Built-in-Functions
set_timerx( )
Syntax:
set_timerX(value)
Parameters:
A 16 bit integer, specifiying the new value of the timer. (int16)
Returns:
Void
Function:
Allows the user to set the value of the timer.
Availability:
This function is available on all devices that have a valid timerX.
Requires:
Examples:
Nothing
Example Files:
Also See:
None
Timer Overview, setup_timerX(), , set_timerX(),
if(EventOccured())
set_timer2(0);//reset the timer.
set_tris_x( )
Syntax:
set_tris_a (value)
set_tris_b (value)
set_tris_c (value)
set_tris_d (value)
set_tris_e (value)
set_tris_f (value)
set_tris_g (value)
set_tris_h (value)
set_tris_j (value)
set_tris_k (value)
Parameters:
value is an 8 bit int with each bit representing a bit of the I/O port.
Returns:
Function:
undefined
These functions allow the I/O port direction (TRI-State) registers to be set. This
must be used with FAST_IO and when I/O ports are accessed as memory such
as when a #BYTE directive is used to access an I/O port. Using the default
standard I/O the built in functions set the I/O direction automatically.
Each bit in the value represents one pin. A 1 indicates the pin is input and a 0
indicates it is output.
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Availability:
Requires:
All devices (however not all devices have all I/O ports)
Nothing
Examples:
SET_TRIS_B( 0x0F );
// B7,B6,B5,B4 are outputs
// B3,B2,B1,B0 are inputs
Example Files:
lcd.c
Also See:
#USE FAST_IO, #USE FIXED_IO, #USE STANDARD_IO, General Purpose I/O
set_uart_speed( )
Syntax:
set_uart_speed (baud, [stream, clock])
Parameters:
baud is a constant representing the number of bits per second.
stream is an optional stream identifier.
clock is an optional parameter to indicate what the current clock is if it is
different from the #use delay value
Returns:
undefined
Function:
Changes the baud rate of the built-in hardware RS232 serial port at run-time.
Availability:
This function is only available on devices with a built in UART.
Requires:
#use rs232
Examples:
// Set baud rate based on setting
// of pins B0 and B1
switch(
case
case
case
case
}
input_b() & 3 ) {
0 : set_uart_speed(2400);
1 : set_uart_speed(4800);
2 : set_uart_speed(9600);
3 : set_uart_speed(19200);
break;
break;
break;
break;
Example Files:
loader.c
Also See:
#USE RS232, putc(), getc(), RS232 I/O overview, setup_uart
226
Built-in-Functions
setjmp( )
Syntax:
Parameters:
result = setjmp (env)
env: The data object that will receive the current environment
Returns:
If the return is from a direct invocation, this function returns 0.
If the return is from a call to the longjmp function, the setjmp function returns a
nonzero value and it's the same value passed to the longjmp function.
Function:
Stores information on the current calling context in a data object of type
jmp_buf and which marks where you want control to pass on a corresponding
longjmp call.
Availability:
Requires:
All devices
#include
Examples:
result = setjmp(jmpbuf);
Example Files:
Also See:
None
longjmp()
setup_adc(mode)
Syntax:
Parameters:
Returns:
Function:
Availability:
Requires:
Examples:
Example Files:
Also See:
setup_adc (mode);
setup_adc2(mode);
mode- Analog to digital mode. The valid options vary depending on the
device. See the devices .h file for all options. Some typical options include:
• ADC_OFF
• ADC_CLOCK_INTERNAL
• ADC_CLOCK_DIV_32
undefined
Configures the analog to digital converter.
Only the devices with built in analog to digital converter.
Constants are defined in the devices .h file.
setup_adc_ports( ALL_ANALOG );
setup_adc(ADC_CLOCK_INTERNAL );
set_adc_channel( 0 );
value = read_adc();
setup_adc( ADC_OFF );
ex_admm.c
setup_adc_ports(), set_adc_channel(), read_adc(), #device , ADC overview,
see header file for device selected
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setup_adc_ports( )
Syntax:
setup_adc_ports (value)
Parameters:
value - a constant defined in the devices .h file
Returns:
undefined
Function:
Sets up the ADC pins to be analog, digital, or a combination and the voltage
reference to use when computing the ADC value. The allowed analog pin
combinations vary depending on the chip and are defined by using the bitwise
OR to concatenate selected pins together. Check the device include file for a
complete list of available pins and reference voltage settings. The constants
ALL_ANALOG and NO_ANALOGS are valid for all chips. Some other example
pin definitions are:
• ANALOG_RA3_REF- All analog and RA3 is the reference
• RA0_RA1_RA3_ANALOG- Just RA0, RA1 and RA3 are analog
Availability:
This function is only available on devices with A/D hardware.
Requires:
Constants are defined in the devices .h file.
Examples:
// All pins analog (that can be)
setup_adc_ports( ALL_ANALOG );
// Pins A0, A1 and A3 are analog and all others
// are digital. The +5v is used as a reference.
setup_adc_ports( RA0_RA1_RA3_ANALOG );
// Pins A0 and A1 are analog. Pin RA3 is used
// for the reference voltage and all other pins
// are digital.
setup_adc_ports( A0_RA1_ANALOGRA3_REF );
Example Files:
ex_admm.c
Also See:
setup_adc(), read_adc(), set_adc_channel() , ADC overview
228
Built-in-Functions
setup_ccp1( )
setup_ccp2( )
setup_ccp3( )
setup_ccp4( )
setup_ccp5( )
setup_ccp6( )
Syntax:
setup_ccp1 (mode)
setup_ccp2 (mode)
setup_ccp3 (mode)
setup_ccp4 (mode)
setup_ccp5 (mode)
setup_ccp6 (mode)
Parameters:
mode is a constant. Valid constants are in the devices .h file and are as follows:
or setup_ccp1 (mode, pwm)
or setup_ccp2 (mode, pwm)
or setup_ccp3 (mode, pwm)
or setup_ccp4 (mode, pwm)
or setup_ccp5 (mode, pwm)
or setup_ccp6 (mode, pwm)
Disable the CCP:
CCP_OFF
Set CCP to capture mode:
CCP_CAPTURE_FE
CCP_CAPTURE_RE
CCP_CAPTURE_DIV_4
CCP_CAPTURE_DIV_16
Capture on falling edge
Capture on rising edge
Capture after 4 pulses
Capture after 16 pulses
Set CCP to compare mode:
CCP_COMPARE_SET_ON_MATCH
CCP_COMPARE_CLR_ON_MATCH
CCP_COMPARE_INT
CCP_COMPARE_RESET_TIMER
Output high on compare
Output low on compare
interrupt on compare
Reset timer on compare
Set CCP to PWM mode:
CCP_PWM
Enable Pulse Width Modulator
pwm parameter is an optional parameter for chips that includes ECCP module.
This parameter allows setting the shutdown time. The value may be 0-255.
CCP_PWM_H_H
CCP_PWM_H_L
CCP_PWM_L_H
CCP_PWM_L_L
CCP_PWM_FULL_BRIDGE
CCP_PWM_FULL_BRIDGE_REV
CCP_PWM_HALF_BRIDGE
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CCP_SHUTDOWN_ON_COMP1
CCP_SHUTDOWN_ON_COMP2
shutdown on Comparator 1 change
shutdown on Comparator 2 change
CCP_SHUTDOWN_ON_COMP
Either Comp. 1 or 2 change
CCP_SHUTDOWN_ON_INT0
VIL on INT pin
CCP_SHUTDOWN_ON_COMP1_INT0
VIL on INT pin or Comparator 1
change
VIL on INT pin or Comparator 2
change
VIL on INT pin or Comparator 1 or
2 change
CCP_SHUTDOWN_ON_COMP2_INT0
CCP_SHUTDOWN_ON_COMP_INT0
CCP_SHUTDOWN_AC_L
CCP_SHUTDOWN_AC_H
CCP_SHUTDOWN_AC_F
Drive pins A nad C high
Drive pins A nad C low
Drive pins A nad C tri-state
CCP_SHUTDOWN_BD_L
CCP_SHUTDOWN_BD_H
CCP_SHUTDOWN_BD_F
Drive pins B nad D high
Drive pins B nad D low
Drive pins B nad D tri-state
CCP_SHUTDOWN_RESTART
the device restart after a shutdown
event
use the dead-band delay
CCP_DELAY
Returns:
Function:
undefined
Initialize the CCP. The CCP counters may be accessed using the long variables
CCP_1 and CCP_2. The CCP operates in 3 modes. In capture mode it will copy
the timer 1 count value to CCP_x when the input pin event occurs. In compare
mode it will trigger an action when timer 1 and CCP_x are equal. In PWM mode it
will generate a square wave. The PCW wizard will help to set the correct mode and
timer settings for a particular application.
Availability:
This function is only available on devices with CCP hardware.
Requires:
Constants are defined in the devices .h file.
Examples:
setup_ccp1(CCP_CAPTURE_RE);
Example
Files:
Also See:
ex_pwm.c, ex_ccpmp.c, ex_ccp1s.c
230
set_pwmX_duty(), CCP1 overview
Built-in-Functions
setup_comparator( )
Syntax:
setup_comparator (mode)
Parameters:
mode is a constant. Valid constants are in the devices .h file and are as
follows:
A0_A3_A1_A2
A0_A2_A1_A2
NC_NC_A1_A2
NC_NC_NC_NC
A0_VR_A1_VR
A3_VR_A2_VR
A0_A2_A1_A2_OUT_ON_A3_A4
A3_A2_A1_A2
Returns:
Function:
undefined
Sets the analog comparator module. The above constants have four parts
representing the inputs: C1-, C1+, C2-, C2+
Availability:
This function is only available on devices with an analog comparator.
Requires
Constants are defined in the devices .h file.
Examples:
// Sets up two independent comparators (C1 and C2),
// C1 uses A0 and A3 as inputs (- and +), and C2
// uses A1 and A2 as inputs
setup_comparator(A0_A3_A1_A2);
Example Files:
Also See:
ex_comp.c
Analog Comparator overview
setup_counters( )
Syntax:
setup_counters (rtcc_state, ps_state)
Parameters:
rtcc_state may be one of the constants defined in the devices .h file. For
example: RTCC_INTERNAL, RTCC_EXT_L_TO_H or RTCC_EXT_H_TO_L
ps_state may be one of the constants defined in the devices .h file.
For example: RTCC_DIV_2, RTCC_DIV_4, RTCC_DIV_8, RTCC_DIV_16,
RTCC_DIV_32, RTCC_DIV_64, RTCC_DIV_128, RTCC_DIV_256,
WDT_18MS, WDT_36MS, WDT_72MS, WDT_144MS, WDT_288MS,
WDT_576MS, WDT_1152MS, WDT_2304MS
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Returns:
undefined
Function:
Sets up the RTCC or WDT. The rtcc_state determines what drives the
RTCC. The PS state sets a prescaler for either the RTCC or WDT. The
prescaler will lengthen the cycle of the indicated counter. If the RTCC prescaler
is set the WDT will be set to WDT_18MS. If the WDT prescaler is set the
RTCC is set to RTCC_DIV_1.
This function is provided for compatibility with older versions. setup_timer_0
and setup_WDT are the recommended replacements when possible. For PCB
devices if an external RTCC clock is used and a WDT prescaler is used then
this function must be used.
Availability:
All devices
Requires:
Constants are defined in the devices .h file.
Examples:
setup_counters (RTCC_INTERNAL, WDT_2304MS);
Example Files:
None
Also See:
setup_wdt(), setup_timer_0(), see header file for device selected
setup_dac( )
Syntax:
setup_dac(mode);
Parameters:
mode- The valid options vary depending on the device. See the devices .h file
for all options. Some typical options include:
· DAC_OUTPUT
Returns:
Function:
undefined
Configures the DAC including reference voltage.
Availability:
Only the devices with built in digital to analog converter.
Requires:
Constants are defined in the devices .h file.
Examples:
setup_dac(DAC_VDD | DAC_OUTPUT);
dac_write(value);
Example Files:
None
232
Built-in-Functions
setup_external_memory( )
Syntax:
SETUP_EXTERNAL_MEMORY( mode );
Parameters:
mode is one or more constants from the device header file OR'ed together.
Returns:
undefined
Function:
Sets the mode of the external memory bus.
Availability:
Only devices that allow external memory.
Requires:
Constants are defined in the device.h file
Examples:
setup_external_memory(EXTMEM_WORD_WRITE
|EXTMEM_WAIT_0 );
setup_external_memory(EXTMEM_DISABLE);
Example Files:
Also See:
None
WRITE_PROGRAM_EEPROM(), WRITE_PROGRAM_MEMORY(), External
Memory overview
setup_lcd( )
Syntax:
setup_lcd (mode, prescale, [segments]);
Parameters:
Mode may be one of these constants from the devices .h file:
• LCD_DISABLED, LCD_STATIC, LCD_MUX12,LCD_MUX13,
LCD_MUX14
The following may be or'ed (via |) with any of the above:
STOP_ON_SLEEP, USE_TIMER_1
See the devices.h file for other device specific options.
Prescale may be 0-15 for the LCD clock.
Segments may be any of the following constants or'ed together:
• SEGO_4, SEG5_8, SEG9_11, SEG12_15, SEG16_19, SEGO_28,
SEG29_31, ALL_LCD_PINS
If omitted the compiler will enable all segments used in the program.
Returns:
undefined
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Function:
This function is used to initialize the 923/924 LCD controller.
Availability:
Only devices with built in LCD drive hardware.
Requires
Constants are defined in the devices .h file.
Examples:
setup_lcd(LCD_MUX14|STOP_ON_SLEEP,2);
Example Files:
ex_92lcd.c
Also See:
lcd_symbol(), lcd_load(), Internal LCD overview
setup_low_volt_detect( )
Syntax:
setup_low_volt_detect(mode)
Parameters:
mode may be one of the constants defined in the devices .h file. LVD_LVDIN,
LVD_45, LVD_42, LVD_40, LVD_38, LVD_36, LVD_35, LVD_33, LVD_30,
LVD_28, LVD_27, LVD_25, LVD_23, LVD_21, LVD_19
One of the following may be or’ed(via |) with the above if high voltage detect is also
available in the device
LVD_TRIGGER_BELOW, LVD_TRIGGER_ABOVE
Returns:
Function:
undefined
This function controls the high/low voltage detect module in the device. The mode
constants specifies the voltage trip point and a direction of change from that point
(available only if high voltage detect module is included in the device). If the device
experiences a change past the trip point in the specified direction the interrupt flag is set
and if the interrupt is enabled the execution branches to the interrupt service routine.
Availability:
This function is only available with devices that have the high/low voltage detect module.
Requires
Constants are defined in the devices.h file.
Examples:
setup_low_volt_detect( LVD_TRIGGER_BELOW | LVD_36 );
This would trigger the interrupt when the voltage is below 3.6 volts
234
Built-in-Functions
setup_oscillator( )
Syntax:
setup_oscillator(mode, finetune)
Parameters:
mode is dependent on the chip. For example, some chips allow speed setting
such as OSC_8MHZ or OSC_32KHZ. Other chips permit changing the source
like OSC_TIMER1.
The finetune (only allowed on certain parts) is a signed int with a range of -31 to +31.
Returns:
Some chips return a state such as OSC_STATE_STABLE to indicate the
oscillator is stable.
Function:
This function controls and returns the state of the internal RC oscillator on some
parts. See the devices .h file for valid options for a particular device.
Note that if INTRC or INTRC_IO is specified in #fuses and a #USE DELAY is
used for a valid speed option, then the compiler will do this setup automatically
at the start of main().
WARNING: If the speed is changed at run time the compiler may not generate
the correct delays for some built in functions. The last #USE DELAY encountered
in the file is always assumed to be the correct speed. You can have multiple
#USE DELAY lines to control the compilers knowledge about the speed.
Availability:
Only parts with a OSCCON register.
Requires:
Constants are defined in the .h file.
Examples:
setup_oscillator( OSC_2MHZ );
Example Files:
Also See:
None
#fuses, Internal oscillator overview
setup_opamp1( )
setup_opamp2( )
Syntax:
setup_opamp1(enabled)
setup_opamp2(enabled)
Parameters:
enabled can be either TRUE or FALSE.
Returns:
Function:
undefined
Enables or Disables the internal operational amplifier peripheral of certain
PICmicros.
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C Compiler Reference Manual August 2009
Availability:
Only parts with a built-in operational amplifier (for example, PIC16F785).
Requires:
Only parts with a built-in operational amplifier (for example, PIC16F785).
Examples:
setup_opamp1(TRUE);
setup_opamp2(boolean_flag);
Example Files:
None
Also See:
None
setup_power_pwm( )
Syntax:
setup_power_pwm(modes, postscale, time_base, period, compare,
compare_postscale, dead_time)
Parameters:
modes values may be up to one from each group of the following:
PWM_CLOCK_DIV_4, PWM_CLOCK_DIV_16,
PWM_CLOCK_DIV_64, PWM_CLOCK_DIV_128
PWM_OFF, PWM_FREE_RUN, PWM_SINGLE_SHOT,
PWM_UP_DOWN, PWM_UP_DOWN_INT
PWM_OVERRIDE_SYNC
PWM_UP_TRIGGER,
PWM_DOWN_TRIGGER
PWM_UPDATE_DISABLE, PWM_UPDATE_ENABLE
PWM_DEAD_CLOCK_DIV_2,
PWM_DEAD_CLOCK_DIV_4,
PWM_DEAD_CLOCK_DIV_8,
PWM_DEAD_CLOCK_DIV_16
postscale is an integer between 1 and 16. This value sets the PWM time base
output postscale.
time_base is an integer between 0 and 65535. This is the initial value of the
PWM base
period is an integer between 0 and 4095. The PWM time base is incremented
until it reaches this number.
compare is an integer between 0 and 255. This is the value that the PWM time
base is compared to, to determine if a special event should be triggered.
236
Built-in-Functions
compare_postscale is an integer between 1 and 16. This postscaler affects
compare, the special events trigger.
dead_time is an integer between 0 and 63. This value specifies the length of
an off period that should be inserted between the going off of a pin and the
going on of it is a complementary pin.
Returns:
undefined
Function:
Initializes and configures the motor control Pulse Width Modulation (PWM)
module.
All devices equipped with PWM.
Availability:
Requires:
Examples:
None
Example Files:
Also See:
None
set_power_pwm_override(), setup_power_pwm_pins(),
set_power_pwmX_duty()
setup_power_pwm(PWM_CLOCK_DIV_4 | PWM_FREE_RUN |
PWM_DEAD_CLOCK_DIV_4,1,10000,1000,0,1,0);
setup_power_pwm_pins( )
Syntax:
setup_power_pwm_pins(module0,module1,module2,module3)
Parameters:
For each module (two pins) specify:
PWM_OFF, PWM_ODD_ON, PWM_BOTH_ON,
PWM_COMPLEMENTARY
Returns:
Function:
undefined
Configures the pins of the Pulse Width Modulation (PWM) device.
Availability:
All devices equipped with a motor control PWM.
Requires:
Examples:
None
Example Files:
None
setup_power_pwm_pins(PWM_OFF, PWM_OFF, PWM_OFF,
PWM_OFF);
setup_power_pwm_pins(PWM_COMPLEMENTARY,
PWM_COMPLEMENTARY, PWM_OFF, PWM_OFF);
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setup_pmp(option,address_mask)
Syntax:
setup_pmp (options,address_mask);
Parameters:
Options- The mode of the Parallel master port. This allows to set the Master
port mode, read-write strobe options and other functionality of the PMPort
module. See the devices .h file for all options. Some typical options include:
·
·
·
·
·
·
PAR_ENABLE
PAR_CONTINUE_IN_IDLE
PAR_INTR_ON_RW - Interrupt on read write
PAR_INC_ADDR – Increment address by 1 every read/write cycle
PAR_MASTER_MODE_1 – Master mode 1
PAR_WAITE4 – 4 Tcy Wait for data hold after strobe
address_mask- This allows the user to setup the address enable register with
a 16 bit value. This value determines which address lines are active from the
available 16 address lines PMA0 : PMA15
Returns:
Undefined.
Function:
Availability:
Configures various options in the PMP module. The options are present in the
device.h file and they are used to setup the module. The PMP module is highly
configurable and this function allows users to setup configurations like the
Master mode, Interrupt options, address increment/decrement options, Address
enable bits and various strobe and delay options.
Only the devices with a built in Parallel Port module.
Requires:
Constants are defined in the devices .h file.
Examples:
setup_pmp( PAR_ENABLE |PAR_MASTER_MODE_1 |
PAR_STOP_IN_IDLE,0x00FF );
// Sets up Master mode with address lines PMA0:PMA7
Example Files:
Also See:
None
setup_pmp(), pmp_address(), pmp_read(), psp_read(), psp_write(),
pmp_write(), psp_output_full(), psp_input_full(), psp_overflow(),
pmp_output_full(), pmp_input_full(),pmp_overflow().
See header file for device selected.
238
Built-in-Functions
setup_qei( )
Syntax:
setup_qei( [unit,]options, filter,maxcount );
Parameters:
Options- The mode of the QEI module. See the devices .h file for all options
Some common options are:
· QEI_MODE_X2
· QEI_TIMER_GATED
· QEI_TIMER_DIV_BY_1
filter- This parameter is optional and the user can specify the digital filter clock
divisor.
maxcount- This will specify the value at which to reset the position counter.
unit- Optional unit number, defaults to 1.
Returns:
void
Function:
Configures the Quadrature Encoder Interface. Various settings like modes,
direction can be setup.
Availability:
Devices that have the QEI module.
Requires:
Nothing.
Examples:
setup_qei(QEI_MODE_X2|QEI_TIMER_INTERNAL,QEI_FILTER_DIV_2,QEI_
FORWARD);
Example Files:
None
Also See:
qei_set_count() , qei_get_count() , qei_status().
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setup_spi( )
setup_spi2( )
Syntax:
setup_spi (mode)
setup_spi2 (mode)
Parameters:
mode may be:
• SPI_MASTER, SPI_SLAVE, SPI_SS_DISABLED
• SPI_L_TO_H, SPI_H_TO_L
• SPI_CLK_DIV_4, SPI_CLK_DIV_16,
• SPI_CLK_DIV_64, SPI_CLK_T2
• Constants from each group may be or'ed together with |.
Returns:
Function:
Availability:
undefined
Initializes the Serial Port Interface (SPI). This is used for 2 or 3 wire serial
devices that follow a common clock/data protocol.
This function is only available on devices with SPI hardware.
Requires:
Constants are defined in the devices .h file.
Examples:
setup_spi(spi_master |spi_l_to_h |
spi_clk_div_16 );
Example Files:
Also See:
ex_spi.c
spi_write(), spi_read(), spi_data_is_in(), SPI overview
setup_psp(option,address_mask)
Syntax:
setup_psp (options,address_mask);
setup_psp(options);
Parameters:
Option- The mode of the Parallel slave port. This allows to set the slave port
mode, read-write strobe options and other functionality of the PMP module.
See the devices .h file for all options. Some typical options include:
·
·
·
·
·
Returns:
240
PAR_PSP_AUTO_INC
PAR_CONTINUE_IN_IDLE
PAR_INTR_ON_RW - Interrupt on read write
PAR_INC_ADDR – Increment address by 1 every read/write cycle
PAR_WAITE4 – 4 Tcy Wait for data hold after strobe
address_mask- This allows the user to setup the address enable register with
a 16 bit value. This value determines which address lines are active from the
available 16 address lines PMA0 : PMA15
Undefined.
Built-in-Functions
Function:
Configures various options in the PMP module. The options are present in the
device.h file and they are used to setup the module. The PMP module is highly
configurable and this function allows users to setup configurations like the
Slave mode, Interrupt options, address increment/decrement options, Address
enable bits and various strobe and delay options.
Availability:
Only the devices with a built in Parallel Port module.
Requires:
Constants are defined in the devices .h file.
Examples:
setup_psp( PAR_PSP_AUTO_INC | PAR_STOP_IN_IDLE,0x00FF );
// Sets up legacy slave mode with read and write buffers auto
increment
Example Files:
Also See:
None
setup_pmp(), pmp_address(),pmp_read(), psp_read(), psp_write(), pmp_write(),
psp_output_full(), psp_input_full(), psp_overflow(),pmp_output_full(),
pmp_input_full(),pmp_overflow(). See header file for device selected.
setup_timer_0( )
Syntax:
setup_timer_0 (mode)
Parameters:
mode may be one or two of the constants defined in the devices .h file.
RTCC_INTERNAL, RTCC_EXT_L_TO_H or RTCC_EXT_H_TO_L
RTCC_DIV_2, RTCC_DIV_4, RTCC_DIV_8, RTCC_DIV_16, RTCC_DIV_32,
RTCC_DIV_64, RTCC_DIV_128, RTCC_DIV_256
PIC18XXX only: RTCC_OFF, RTCC_8_BIT
One constant may be used from each group or'ed together with the | operator.
Returns:
Function:
undefined
Sets up the timer 0 (aka RTCC).
Availability:
Requires:
Examples:
All devices.
Constants are defined in the devices .h file.
Example Files:
Also See:
None
get_timer0(), set_timer0(), setup_counters()
setup_timer_0 (RTCC_DIV_2|RTCC_EXT_L_TO_H);
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setup_timer_1( )
Syntax:
setup_timer_1 (mode)
Parameters:
mode values may be:
• T1_DISABLED, T1_INTERNAL, T1_EXTERNAL,
T1_EXTERNAL_SYNC
• T1_CLK_OUT
• T1_DIV_BY_1, T1_DIV_BY_2, T1_DIV_BY_4, T1_DIV_BY_8
• constants from different groups may be or'ed together with |.
Returns:
Function:
undefined
Initializes timer 1. The timer value may be read and written to using
SET_TIMER1() and GET_TIMER1(). Timer 1 is a 16 bit timer.
Availability:
With an internal clock at 20mhz and with the T1_DIV_BY_8 mode, the timer will
increment every 1.6us. It will overflow every 104.8576ms.
This function is only available on devices with timer 1 hardware.
Requires:
Constants are defined in the devices .h file.
Examples:
setup_timer_1 ( T1_DISABLED );
setup_timer_1 ( T1_INTERNAL | T1_DIV_BY_4 );
setup_timer_1 ( T1_INTERNAL | T1_DIV_BY_8 );
Example Files:
None
Also See:
get_timer1(), set_timer1(), Timer1 overview
242
Built-in-Functions
setup_timer_2( )
Syntax:
setup_timer_2 (mode, period, postscale)
Parameters:
mode may be one of:
•
T2_DISABLED, T2_DIV_BY_1, T2_DIV_BY_4,
T2_DIV_BY_16
period is a int 0-255 that determines when the clock value is reset,
postscale is a number 1-16 that determines how many timer overflows before
an interrupt: (1 means once, 2 means twice, and so on).
Returns:
undefined
Function:
Initializes timer 2. The mode specifies the clock divisor (from the oscillator
clock). The timer value may be read and written to using GET_TIMER2()
and SET_TIMER2(). Timer 2 is a 8 bit counter/timer.
Availability:
This function is only available on devices with timer 2 hardware.
Requires:
Constants are defined in the devices .h file.
Examples:
setup_timer_2 ( T2_DIV_BY_4, 0xc0, 2);
// At 20mhz, the timer will increment every 800ns,
// will overflow every 154.4us,
// and will interrupt every 308.8us.
Example Files:
Also See:
None
get_timer2(), set_timer2(), Timer2 overview
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setup_timer_3( )
Syntax:
setup_timer_3 (mode)
Parameters:
Mode may be one of the following constants from each group or'ed (via |)
together:
•
T3_DISABLED, T3_INTERNAL, T3_EXTERNAL,
T3_EXTERNAL_SYNC
•
T3_DIV_BY_1, T3_DIV_BY_2, T3_DIV_BY_4,
T3_DIV_BY_8
Returns:
undefined
Function:
Initializes timer 3 or 4. The mode specifies the clock divisor (from the oscillator
clock). The timer value may be read and written to using GET_TIMER3()
and SET_TIMER3(). Timer 3 is a 16 bit counter/timer.
Availability:
This function is only available on PIC®18 devices.
Requires:
Constants are defined in the devices .h file.
Examples:
setup_timer_3 (T3_INTERNAL | T3_DIV_BY_2);
Example Files:
None
Also See:
get_timer3(), set_timer3()
244
Built-in-Functions
setup_timer_4( )
Syntax:
setup_timer_4 (mode, period, postscale)
Parameters:
mode may be one of:
•
T4_DISABLED, T4_DIV_BY_1, T4_DIV_BY_4,
T4_DIV_BY_16
period is a int 0-255 that determines when the clock value is reset,
postscale is a number 1-16 that determines how many timer overflows before
an interrupt: (1 means once, 2 means twice, and so on).
Returns:
undefined
Function:
Initializes timer 4. The mode specifies the clock divisor (from the oscillator
clock). The timer value may be read and written to using GET_TIMER4() and
SET_TIMER4(). Timer 4 is a 8 bit counter/timer.
Availability:
This function is only available on devices with timer 4 hardware.
Requires:
Constants are defined in the devices .h file
Examples:
setup_timer_4 ( T4_DIV_BY_4, 0xc0, 2);
// At 20mhz, the timer will increment every 800ns,
// will overflow every 153.6us,
// and will interrupt every 307.2us.
Example Files:
Also See:
get_timer4(), set_timer4()
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setup_timer_5( )
Syntax:
setup_timer_5 (mode)
Parameters:
mode may be one or two of the constants defined in the devices .h file.
T5_DISABLED, T5_INTERNAL, T5_EXTERNAL, or T5_EXTERNAL_SYNC
T5_DIV_BY_1, T5_DIV_BY_2, T5_DIV_BY_4, T5_DIV_BY_8
T5_ONE_SHOT, T5_DISABLE_SE_RESET, or T5_ENABLE_DURING_SLEEP
Returns:
undefined
Function:
Initializes timer 5. The mode specifies the clock divisor (from the oscillator
clock). The timer value may be read and written to using GET_TIMER5()
and SET_TIMER5(). Timer 5 is a 16 bit counter/timer.
Availability:
This function is only available on PIC®18 devices.
Requires:
Constants are defined in the devices .h file.
Examples:
setup_timer_5 (T5_INTERNAL | T5_DIV_BY_2);
Example Files:
None
Also See:
get_timer5(), set_timer5(), Timer5 overview
246
Built-in-Functions
setup_uart( )
Syntax:
setup_uart(baud, stream)
setup_uart(baud)
setup_uart(baud, stream, clock)
Parameters:
baud is a constant representing the number of bits per second. A one or zero
may also be passed to control the on/off status. Stream is an optional stream
identifier.
Chips with the advanced UART may also use the following constants:
UART_ADDRESS UART only accepts data with 9th bit=1
UART_DATA UART accepts all data
Chips with the EUART H/W may use the following constants:
UART_AUTODETECT Waits for 0x55 character and sets the UART baud rate
to match.
UART_AUTODETECT_NOWAIT Same as above function, except returns
before 0x55 is received. KBHIT() will be true when the match is made. A call
to GETC() will clear the character.
UART_WAKEUP_ON_RDA Wakes PIC up out of sleep when RCV goes from
high to low
clock - If specified this is the clock rate this function should assume. The
default comes from the #USE DELAY.
Returns:
undefined
Function:
Very similar to SET_UART_SPEED. If 1 is passed as a parameter, the UART
is turned on, and if 0 is passed, UART is turned off. If a BAUD rate is passed to
it, the UART is also turned on, if not already on.
Availability:
This function is only available on devices with a built in UART.
Requires:
#use rs232
Examples:
setup_uart(9600);
setup_uart(9600, rsOut);
Example Files:
None
Also See:
#USE RS232, putc(), getc(), RS232 I/O overview
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setup_vref( )
Syntax:
setup_vref (mode | value)
Parameters:
mode may be one of the following constants:
•
FALSE
(off)
•
VREF_LOW
for VDD*VALUE/24
•
VREF_HIGH
for VDD*VALUE/32 + VDD/4
•
any may be or'ed with VREF_A2.
value is an int 0-15.
Returns:
undefined
Function:
Establishes the voltage of the internal reference that may be used for analog
compares and/or for output on pin A2.
Availability:
This function is only available on devices with VREF hardware.
Requires:
Constants are defined in the devices .h file.
Examples:
setup_vref (VREF_HIGH | 6);
// At VDD=5, the voltage is 2.19V
Example Files:
ex_comp.c
Also See:
Voltage Reference overview
248
Built-in-Functions
setup_wdt( )
Syntax:
Parameters:
setup_wdt (mode)
For PCB/PCM parts: WDT_18MS, WDT_36MS, WDT_72MS,
WDT_144MS,WDT_288MS, WDT_576MS, WDT_1152MS, WDT_2304MS
For PIC®18 parts: WDT_ON, WDT_OFF
For PIC®16 parts with software controlled WDT enabled: WDT_ON,
WDT_OFF, WDT_TIMES_32, WDT_TIMES_64, WDT_TIMES_128,
WDT_TIMES_256, WDT_TIMES_512, WDT_TIMES_1024,
WDT_TIMES_2048, WDT_TIMES_4096, WDT_TIMES_8192,
WDT_TIMES_16384, WDT_TIMES_32768, WDT_TIMES_65536.
Returns:
Function:
undefined
Sets up the watchdog timer.
The watchdog timer is used to cause a hardware reset if the software appears
to be stuck.
The timer must be enabled, the timeout time set and software must periodically restart
the timer. These are done differently on the PCB/PCM and PCH parts as follows:
PCB/PCM
PCH
Enable/Disable
#fuses
#fuses
Timeout time
setup_wdt()
#fuses
restart
restart_wdt()
restart_wdt()
Availability:
Requires:
Examples:
Example Files:
Also See:
Note: For PCH parts and PCM parts with software controlled WDT, setup_wdt( )
would enable/disable watchdog timer only if NOWDT fuse is set. If WDT fuse is
set, watchdog timer is always enabled.
Note: WDT_OFF should not be used with any other options.
Warning: SETUP_WDT() should be called before Timer0 is set up.
All devices
#fuses, Constants are defined in the devices .h file.
#fuses WDT1, WDT // PIC18 example, See
// restart_wdt for a PIC18 example
main() {
// WDT1 means 18ms*1 for old PIC18s and 4ms*1
for new PIC18s
// setup_wdt(WDT_ON);
while (TRUE) {
restart_wdt();
perform_activity();
}
}
ex_wdt.c
#fuses, restart_wdt(), WDT or Watch Dog Timer overview
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shift_left( )
Syntax:
shift_left (address, bytes, value)
Parameters:
address is a pointer to memory, bytes is a count of the number of bytes to
work with, value is a 0 to 1 to be shifted in.
Returns:
0 or 1 for the bit shifted out
Function:
Shifts a bit into an array or structure. The address may be an array identifier or
an address to a structure (such as &data). Bit 0 of the lowest byte in RAM is
treated as the LSB.
Availability:
All devices
Requires:
Nothing
Examples:
byte buffer[3];
for(i=0; i<=24; ++i){
// Wait for clock high
while (!input(PIN_A2));
shift_left(buffer,3,input(PIN_A3));
// Wait for clock low
while (input(PIN_A2));
}
// reads 24 bits from pin A3,each bit is read
// on a low to high on pin A2
Example Files:
ex_extee.c, 9356.c
Also See:
shift_right(), rotate_right(), rotate_left(),
250
Built-in-Functions
shift_right( )
Syntax:
shift_right (address, bytes, value)
Parameters:
address is a pointer to memory, bytes is a count of the number of bytes to
work with, value is a 0 to 1 to be shifted in.
Returns:
0 or 1 for the bit shifted out
Function:
Shifts a bit into an array or structure. The address may be an array identifier or
an address to a structure (such as &data). Bit 0 of the lowest byte in RAM is
treated as the LSB.
Availability:
All devices
Requires:
Nothing
Examples:
// reads 16 bits from pin A1, each bit is read
// on a low to high on pin A2
struct {
byte time;
byte command : 4;
byte source : 4;} msg;
for(i=0; i<=16; ++i) {
while(!input(PIN_A2));
shift_right(&msg,3,input(PIN_A1));
while (input(PIN_A2)) ;}
// This shifts 8 bits out PIN_A0, LSB first.
for(i=0;i<8;++i)
output_bit(PIN_A0,shift_right(&data,1,0));
Example Files:
ex_extee.c, 9356.c
Also See:
shift_left(), rotate_right(), rotate_left(),
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sin( )
cos( )
tan( )
asin( )
acos()
atan()
sinh()
cosh()
tanh()
atan2()
Syntax:
val = sin (rad)
val = cos (rad)
val = tan (rad)
rad = asin (val)
rad1 = acos (val)
rad = atan (val)
rad2=atan2(val, val)
result=sinh(value)
result=cosh(value)
result=tanh(value)
Parameters:
rad is a float representing an angle in Radians -2pi to 2pi.
val is a float with the range -1.0 to 1.0.
Value is a float
Returns:
rad is a float representing an angle in Radians -pi/2 to pi/2
val is a float with the range -1.0 to 1.0.
rad1 is a float representing an angle in Radians 0 to pi
rad2 is a float representing an angle in Radians -pi to pi
Result is a float
Function:
These functions perform basic Trigonometric functions.
sin
returns the sine value of the parameter (measured in radians)
cos
returns the cosine value of the parameter (measured in radians)
tan
returns the tangent value of the parameter (measured in radians)
asin returns the arc sine value in the range [-pi/2,+pi/2] radians
acos returns the arc cosine value in the range[0,pi] radians
atan returns the arc tangent value in the range [-pi/2,+pi/2] radians
atan2 returns the arc tangent of y/x in the range [-pi,+pi] radians
sinh returns the hyperbolic sine of x
cosh returns the hyperbolic cosine of x
tanh returns the hyperbolic tangent of x
Note on error handling:
If "errno.h" is included then the domain and range errors are stored in the errno
variable. The user can check the errno to see if an error has occurred and print
252
Built-in-Functions
the error using the perror function.
Domain error occurs in the following cases:
asin: when the argument not in the range[-1,+1]
acos: when the argument not in the range[-1,+1]
atan2: when both arguments are zero
Range error occur in the following cases:
cosh: when the argument is too large
sinh: when the argument is too large
Availability:
All devices
Requires:
#include
Examples:
float phase;
// Output one sine wave
for(phase=0; phase<2*3.141596; phase+=0.01)
set_analog_voltage( sin(phase)+1 );
Example Files:
ex_tank.c
Also See:
log(), log10(), exp(), pow(), sqrt()
sleep( )
Syntax:
sleep(mode)
Parameters:
Returns:
Function:
None
Undefined
Issues a SLEEP instruction. Details are device dependent. However, in
general the part will enter low power mode and halt program execution until
woken by specific external events. Depending on the cause of the wake up
execution may continue after the sleep instruction. The compiler inserts a
sleep() after the last statement in main().
Availability:
Requires:
Examples:
All devices
Nothing
Example Files:
ex_wakup.c
Also See:
reset_cpu()
SLEEP();
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sleep_ulpwu( )
Syntax:
sleep_ulpwu(time)
Parameters:
time specifies how long, in us, to charge the capacitor on the ultra-low power
wakeup pin (by outputting a high on PIN_A0).
Returns:
Function:
undefined
Charges the ultra-low power wake-up capacitor on PIN_A0 for time
microseconds, and then puts the PIC to sleep. The PIC will then wake-up on an
'Interrupt-on-Change' after the charge on the cap is lost.
Availability:
Ultra Low Power Wake-Up support on the PIC (example, PIC12F683)
Requires:
Examples:
#use delay
Example Files:
Also See:
while(TRUE)
{
if (input(PIN_A1))
//do something
else
sleep_ulpwu(10);
goto sleep
}
//cap will be charged for 10us, then
None
#use delay
spi_data_is_in( )
spi_data_is_in2( )
Syntax:
result = spi_data_is_in()
result = spi_data_is_in2()
Parameters:
Returns:
None
0 (FALSE) or 1 (TRUE)
Function:
Availability:
Requires:
Examples:
Returns TRUE if data has been received over the SPI.
This function is only available on devices with SPI hardware.
Nothing
Example Files:
254
( !spi_data_is_in() && input(PIN_B2) );
if( spi_data_is_in() )
data = spi_read();
None
Built-in-Functions
spi_read( )
spi_read2( )
Syntax:
value = spi_read (data)
value = spi_read2 (data)
Parameters:
data is optional and if included is an 8 bit int.
Returns:
An 8 bit int
Function:
Return a value read by the SPI. If a value is passed to SPI_READ the data will
be clocked out and the data received will be returned. If no data is ready,
SPI_READ will wait for the data.
If this device is the master then either do a SPI_WRITE(data) followed by a
SPI_READ() or do a SPI_READ(data). These both do the same thing and will
generate a clock. If there is no data to send just do a SPI_READ(0) to get the
clock.
If this device is a slave then either call SPI_READ() to wait for the clock and
data or use SPI_DATA_IS_IN() to determine if data is ready.
Availability:
This function is only available on devices with SPI hardware.
Requires:
Nothing
Examples:
in_data = spi_read(out_data);
Example Files:
ex_spi.c
Also See:
spi_data_is_in(), spi_write(), SPI overview
spi_write( )
spi_write2( )
Syntax:
SPI_WRITE (value)
SPI_WRITE2 (value)
Parameters:
value is an 8 bit int
Returns:
Function:
Nothing
Sends a byte out the SPI interface. This will cause 8 clocks to be generated.
This function will write the value out to the SPI. At the same time data is
clocked out data is clocked in and stored in a receive buffer. SPI_READ may
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C Compiler Reference Manual August 2009
be used to read the buffer.
Availability:
This function is only available on devices with SPI hardware.
Requires:
Examples:
Nothing
Example Files:
ex_spi.c
Also See:
spi_read(), spi_data_is_in(), SPI overview
spi_write( data_out );
data_in = spi_read();
spi_xfer( )
Syntax:
spi_xfer(data)
spi_xfer(stream, data)
spi_xfer(stream, data, bits)
result = spi_xfer(data)
result = spi_xfer(stream, data)
result = spi_xfer(stream, data, bits)
Parameters:
data is the variable or constant to transfer via SPI. The pin used to transfer
data is defined in the DO=pin option in #use spi. stream is the SPI stream to
use as defined in the STREAM=name option in #use spi. bits is how many bits
of data will be transferred.
Returns:
The data read in from the SPI. The pin used to transfer result is defined in the
DI=pin option in #use spi.
Function:
Transfers data to and reads data from an SPI device.
Availability:
All devices with SPI support.
Requires:
#use spi
Examples:
int i = 34;
spi_xfer(i);
// transfers the number 34 via SPI
int trans = 34, res;
res = spi_xfer(trans);
// transfers the number 34 via SPI
// also reads the number coming in from SPI
Example Files:
Also See:
None
#USE SPI
256
Built-in-Functions
sprintf( )
Syntax:
sprintf(string, cstring, values...);
bytes=sprintf(string, cstring, values...)
Parameters:
string is an array of characters.
cstring is a constant string or an array of characters null terminated. Values
are a list of variables separated by commas.
Returns:
Bytes is the number of bytes written to string.
Function:
This function operates like printf except that the output is placed into the specified
string. The output string will be terminated with a null. No checking is done to
ensure the string is large enough for the data. See printf() for details on formatting.
Availability:
Requires:
Examples:
All devices.
Nothing
char mystring[20];
long mylong;
mylong=1234;
sprintf(mystring,"<%lu>",mylong);
// mystring now has:
//
< 1 2 3 4 > \0
Example Files:
Also See:
None
printf()
sqrt( )
Syntax:
result = sqrt (value)
Parameters:
value is a float
Returns:
A float
Function:
Computes the non-negative square root of the float value x. If the argument is
negative, the behavior is undefined.
Note on error handling:
If "errno.h" is included then the domain and range errors are stored in the errno
variable. The user can check the errno to see if an error has occurred and print
the error using the perror function.
Domain error occurs in the following cases:
sqrt: when the argument is negative
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Availability:
All devices.
Requires:
#include
Examples:
distance = sqrt( pow((x1-x2),2)+pow((y1-y2),2) );
Example Files:
None
Also See:
None
srand( )
Syntax:
srand(n)
Parameters:
n is the seed for a new sequence of pseudo-random numbers to be returned by
subsequent calls to rand.
Returns:
No value.
Function:
The srand function uses the argument as a seed for a new sequence of
pseudo-random numbers to be returned by subsequent calls to rand. If srand is
then called with same seed value, the sequence of random numbers shall be
repeated. If rand is called before any call to srand have been made, the same
sequence shall be generated as when srand is first called with a seed value of 1.
Availability:
All devices.
Requires:
#include
Examples:
srand(10);
I=rand();
Example Files:
None
Also See:
rand()
258
Built-in-Functions
STANDARD STRING
FUNCTIONS( )
memchr( )
memcmp( )
strcat( )
strchr( )
strcmp( )
Syntax:
Parameters:
strcoll( )
strcspn( )
strerror( )
stricmp( )
strlen( )
strlwr( )
strncat( )
strncmp( )
strncpy( )
strpbrk( )
strrchr( )
strspn( )
strstr( )
strxfrm( )
ptr=strcat (s1, s2)
ptr=strchr (s1, c)
ptr=strrchr (s1, c)
cresult=strcmp (s1, s2)
iresult=strncmp (s1, s2, n)
iresult=stricmp (s1, s2)
ptr=strncpy (s1, s2, n)
iresult=strcspn (s1, s2)
iresult=strspn (s1, s2)
iresult=strlen (s1)
ptr=strlwr (s1)
ptr=strpbrk (s1, s2)
ptr=strstr (s1, s2)
ptr=strncat(s1,s2)
iresult=strcoll(s1,s2)
Concatenate s2 onto s1
Find c in s1 and return &s1[i]
Same but search in reverse
Compare s1 to s2
Compare s1 to s2 (n bytes)
Compare and ignore case
Copy up to n characters s2->s1
Count of initial chars in s1 not in s2
Count of initial chars in s1 also in s2
Number of characters in s1
Convert string to lower case
Search s1 for first char also in s2
Search for s2 in s1
Concatenates up to n bytes of s2 onto s1
Compares s1 to s2, both interpreted as
appropriate to the current locale.
res=strxfrm(s1,s2,n)
Transforms maximum of n characters of s2 and
places them in s1, such that strcmp(s1,s2) will
give the same result as strcoll(s1,s2)
iresult=memcmp(m1,m2,n)
Compare m1 to m2 (n bytes)
ptr=memchr(m1,c,n)
Find c in first n characters of m1 and return
&m1[i]
ptr=strerror(errnum)
Maps the error number in errnum to an error
message string. The parameters 'errnum' is an
unsigned 8 bit int. Returns a pointer to the string.
s1 and s2 are pointers to an array of characters (or the name of an array).
Note that s1 and s2 MAY NOT BE A CONSTANT (like "hi").
n is a count of the maximum number of character to operate on.
c is a 8 bit character
m1 and m2 are pointers to memory.
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Returns:
ptr is a copy of the s1 pointer
iresult is an 8 bit int
result is -1 (less than), 0 (equal) or 1 (greater than)
res is an integer.
Function:
Functions are identified above.
Availability:
All devices.
Requires:
#include
Examples:
char string1[10], string2[10];
strcpy(string1,"hi ");
strcpy(string2,"there");
strcat(string1,string2);
printf("Length is %u\r\n", strlen(string1));
// Will print 8
Example Files:
ex_str.c
Also See:
strcpy(), strtok()
strcpy( )
strcopy( )
Syntax:
strcpy (dest, src)
strcopy (dest, src)
Parameters:
dest is a pointer to a RAM array of characters.
src may be either a pointer to a RAM array of characters or it may be a
constant string.
Returns:
undefined
Function:
Copies a constant or RAM string to a RAM string. Strings are terminated with a
0.
Availability:
All devices.
Requires:
Nothing
260
Built-in-Functions
Examples:
char string[10], string2[10];
.
.
.
strcpy (string, "Hi There");
strcpy(string2,string);
Example Files:
ex_str.c
Also See:
strxxxx()
strtod( )
Syntax:
result=strtod(nptr,& endptr)
Parameters:
nptr and endptr are strings
Returns:
result is a float.
returns the converted value in result, if any. If no conversion could be
performed, zero is returned.
Function:
The strtod function converts the initial portion of the string pointed to by nptr to
a float representation. The part of the string after conversion is stored in the
object pointed to endptr, provided that endptr is not a null pointer. If nptr is
empty or does not have the expected form, no conversion is performed and the
value of nptr is stored in the object pointed to by endptr, provided endptr is not
a null pointer.
Availability:
All devices.
Requires:
#include
Examples:
float result;
char str[12]="123.45hello";
char *ptr;
result=strtod(str,&ptr);
//result is 123.45 and ptr is "hello"
Example Files:
None
Also See:
strtol(), strtoul()
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C Compiler Reference Manual August 2009
strtok( )
Syntax:
ptr = strtok(s1, s2)
Parameters:
s1 and s2 are pointers to an array of characters (or the name of an array).
Note that s1 and s2 MAY NOT BE A CONSTANT (like "hi"). s1 may be 0 to
indicate a continue operation.
Returns:
ptr points to a character in s1 or is 0
Function:
Finds next token in s1 delimited by a character from separator string s2 (which
can be different from call to call), and returns pointer to it.
First call starts at beginning of s1 searching for the first character NOT
contained in s2 and returns null if there is none are found.
If none are found, it is the start of first token (return value). Function then
searches from there for a character contained in s2.
If none are found, current token extends to the end of s1, and subsequent
searches for a token will return null.
If one is found, it is overwritten by '\0', which terminates current token.
Function saves pointer to following character from which next search will start.
Each subsequent call, with 0 as first argument, starts searching from the saved pointer.
Availability:
Requires:
Examples:
All devices.
#include
char string[30], term[3], *ptr;
strcpy(string,"one,two,three;");
strcpy(term,",;");
ptr = strtok(string, term);
while(ptr!=0) {
puts(ptr);
ptr = strtok(0, term);
}
// Prints:
one
two
three
Example Files:
Also See:
262
ex_str.c
strxxxx(), strcpy()
Built-in-Functions
strtol( )
Syntax:
result=strtol(nptr,& endptr, base)
Parameters:
nptr and endptr are strings and base is an integer
Returns:
result is a signed long int.
returns the converted value in result , if any. If no conversion could be
performed, zero is returned.
Function:
The strtol function converts the initial portion of the string pointed to by nptr to a
signed long int representation in some radix determined by the value of base.
The part of the string after conversion is stored in the object pointed to endptr,
provided that endptr is not a null pointer. If nptr is empty or does not have the
expected form, no conversion is performed and the value of nptr is stored in the
object pointed to by endptr, provided endptr is not a null pointer.
Availability:
All devices.
Requires:
#include
Examples:
signed long result;
char str[9]="123hello";
char *ptr;
result=strtol(str,&ptr,10);
//result is 123 and ptr is "hello"
Example Files:
None
Also See:
strtod(), strtoul()
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strtoul( )
Syntax:
result=strtoul(nptr,endptr, base)
Parameters:
nptr and endptr are strings pointers and base is an integer 2-36.
Returns:
result is an unsigned long int.
returns the converted value in result , if any. If no conversion could be
performed, zero is returned.
Function:
The strtoul function converts the initial portion of the string pointed to by nptr to
a long int representation in some radix determined by the value of base. The
part of the string after conversion is stored in the object pointed to endptr,
provided that endptr is not a null pointer. If nptr is empty or does not have the
expected form, no conversion is performed and the value of nptr is stored in the
object pointed to by endptr, provided endptr is not a null pointer.
Availability:
Requires:
All devices.
STDLIB.H must be included
Examples:
long result;
char str[9]="123hello";
char *ptr;
result=strtoul(str,&ptr,10);
//result is 123 and ptr is "hello"
Example Files:
Also See:
None
strtol(), strtod()
swap( )
Syntax:
swap (lvalue)
Parameters:
lvalue is a byte variable
Returns:
undefined - WARNING: this function does not return the result
Function:
Swaps the upper nibble with the lower nibble of the specified byte. This is the
same as:
byte = (byte << 4) | (byte >> 4);
Availability:
All devices.
264
Built-in-Functions
Requires:
Nothing
Examples:
x=0x45;
swap(x);
//x now is 0x54
Example Files:
Also See:
None
rotate_right(), rotate_left()
tolower( )
toupper( )
Syntax:
result = tolower (cvalue)
result = toupper (cvalue)
Parameters:
cvalue is a character
Returns:
An 8 bit character
Function:
These functions change the case of letters in the alphabet.
TOLOWER(X) will return 'a'..'z' for X in 'A'..'Z' and all other characters are
unchanged. TOUPPER(X) will return 'A'..'Z' for X in 'a'..'z' and all other
characters are unchanged.
Availability:
All devices.
Requires:
Nothing
Examples:
switch(
case
case
case
}
Example Files:
ex_str.c
Also See:
None
toupper(getc()) ) {
'R' : read_cmd(); break;
'W' : write_cmd(); break;
'Q' : done=TRUE;
break;
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C Compiler Reference Manual August 2009
touchpad_getc( )
Syntax:
input = TOUCHPAD_GETC( );
Parameters:
None
Returns:
char (returns corresponding ASCII number is “input” declared as int)
Function:
Actively waits for firmware to signal that a pre-declared Capacitive Sensing Module
(CSM) pin is active, then stores the pre-declared character value of that pin in “inp
Note: Until a CSM pin is read by firmware as active, this instruction will cause the
microcontroller to stall.
Availability:
All PIC's with a CSM Module
Requires:
#USE TOUCHPAD (options)
Examples:
// When the pad connected to PIN_B0 is activated, store the lett
'A'
#USE TOUCHPAD (PIN_B0='A')
void main(void){
char c;
enable_interrupts(GLOBAL);
c = TOUCHPAD_GETC(); //will wait until one of declared pins is detected
//if PIN_B0 is pressed, c will get value 'A'
}
Example Files:
None
Also See:
#USE TOUCHPAD( ), touchpad_state( )
266
Built-in-Functions
touchpad_hit( )
Syntax:
value = TOUCHPAD_HIT( ). if( TOUCHPAD_HIT( ) )
Parameters:
None
Returns:
TRUE or FALSE
Function:
Returns TRUE if a Capacitive Sensing Module (CSM) key has been pressed. If TR
then a call to TOUCHPAD_GETC( ) will not cause the program to wait for a key pr
Availability:
All PIC's with a CSM Module
Requires:
#USE TOUCHPAD (options)
Examples:
// When the pad connected to PIN_B0 is activated, store the
letter 'A'
#USE TOUCHPAD (PIN_B0='A')
void main(void){
char c;
enable_interrupts(GLOBAL);
while (TRUE) {
if ( TOUCHPAD_HIT() )
c = TOUCHPAD_GETC();
}
//wait until key on PIN_B0 is pressed
//get key that was pressed
//c will get value 'A'
}
Example Files:
None
Also See:
#USE TOUCHPAD ( ), touchpad_state( ), touchpad_getc( )
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touchpad_state( )
Syntax:
TOUCHPAD_STATE (state);
Parameters:
state is a literal 0, 1, or 2.
Returns:
None
Function:
Sets the current state of the touchpad connected to the Capacitive Sensing
Module (CSM). The state can be one of the following three values:
0 : Normal state
1 : Calibrates, then enters normal state
2 : Test mode, data from each key is collected in the int16 array
TOUCHDATA
Note: If the state is set to 1 while a key is being pressed, the touchpad will not calibra
properly.
Availability:
All PIC's with a CSM Module
Requires:
#USE TOUCHPAD (options)
Examples:
#USE TOUCHPAD (THRESHOLD=5, PIN_D5='5', PIN_B0='C')
void main(void){
char c;
TOUCHPAD_STATE(1);
enable_interrupts(GLOBAL);
while(1){
c = TOUCHPAD_GETC();
detected
}
}
//calibrates, then enters normal state
//will wait until one of declared pins is
//if PIN_B0 is pressed, c will get value 'C'
//if PIN_D5 is pressed, c will get value '5'
Example Files:
None
Also See:
#USE TOUCHPAD ( ), touchpad_getc( ), touchpad_hit( )
268
Built-in-Functions
va_arg( )
Syntax:
va_arg(argptr, type)
Parameters:
argptr is a special argument pointer of type va_list
type – This is data type like int or char.
Returns:
The first call to va_arg after va_start return the value of the parameters after
that specified by the last parameter. Successive invocations return the values of
the remaining arguments in succession.
Function:
The function will return the next argument every time it is called.
Availability:
All devices.
Requires:
#include
Examples:
int foo(int num, ...)
{
int sum = 0;
int i;
va_list argptr; // create special argument pointer
va_start(argptr,num); // initialize argptr
for(i=0; i
Examples:
int foo(int num, ...)
{
int sum = 0;
int i;
va_list argptr; // create special argument pointer
va_start(argptr,num); // initialize argptr
for(i=0; i
Examples:
int foo(int num, ...)
{
int sum = 0;
int i;
va_list argptr; // create special argument pointer
va_start(argptr,num); // initialize argptr
for(i=0; i getenv(“FLASH_WRITE_SIZE”)
WRITE_PROGRAM_EEPROM - Writes 2 bytes, does not erase (use
ERASE_PROGRAM_EEPROM)
WRITE_PROGRAM_MEMORY - Writes any number of bytes, will erase
a block whenever the first (lowest) byte in a block is written to. If the
first address is not the start of a block that block is not erased.
ERASE_PROGRAM_EEPROM - Will erase a block. The lowest
address bits are not used.
For chips where
getenv(“FLASH_ERASE_SIZE”) = getenv(“FLASH_WRITE_SIZE”)
WRITE_PROGRAM_EEPROM - Writes 2 bytes, no erase is needed.
WRITE_PROGRAM_MEMORY - Writes any number of bytes, bytes
outside the range of the write block are not changed. No erase is needed.
ERASE_PROGRAM_EEPROM - Not available
276
STANDARD C INCLUDE FILES
errno.h
errno.h
EDOM
ERANGE
errno
Domain error value
Range error value
error value
float.h
float.h
FLT_RADIX:
FLT_MANT_DIG:
FLT_DIG:
FLT_MIN_EXP:
FLT_MIN_10_EXP:
FLT_MAX_EXP:
FLT_MAX_10_EXP:
FLT_MAX:
FLT_EPSILON:
FLT_MIN:
DBL_MANT_DIG:
DBL_DIG:
DBL_MIN_EXP:
DBL_MIN_10_EXP:
DBL_MAX_EXP:
DBL_MAX_10_EXP:
Radix of the exponent representation
Number of base digits in the floating point significant
Number of decimal digits, q, such that any floating point number with
q decimal digits can be rounded into a floating point number with p
radix b digits and back again without change to the q decimal digits.
Minimum negative integer such that FLT_RADIX raised to that
power minus 1 is a normalized floating-point number.
Minimum negative integer such that 10 raised to that power is in the
range of normalized floating-point numbers.
Maximum negative integer such that FLT_RADIX raised to that
power minus 1 is a representable finite floating-point number.
Maximum negative integer such that 10 raised to that power is in the
range representable finite floating-point numbers.
Maximum representable finite floating point number.
The difference between 1 and the least value greater than 1 that is
representable in the given floating point type.
Minimum normalized positive floating point number.
Number of base digits in the floating point significant
Number of decimal digits, q, such that any floating point number with
q decimal digits can be rounded into a floating point number with p
radix b digits and back again without change to the q decimal digits.
Minimum negative integer such that FLT_RADIX raised to that
power minus 1 is a normalized floating point number.
Minimum negative integer such that 10 raised to that power is in the
range of normalized floating point numbers.
Maximum negative integer such that FLT_RADIX raised to that
power minus 1 is a representable finite floating point number.
Maximum negative integer such that 10 raised to that power is in the
range of representable finite floating point numbers.
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DBL_MAX:
DBL_EPSILON:
DBL_MIN:
LDBL_MANT_DIG:
LDBL_DIG:
LDBL_MIN_EXP:
LDBL_MIN_10_EXP:
LDBL_MAX_EXP:
LDBL_MAX_10_EXP:
LDBL_MAX:
LDBL_EPSILON:
LDBL_MIN:
Maximum representable finite floating point number.
The difference between 1 and the least value greater than 1 that is
representable in the given floating point type.
Minimum normalized positive floating point number.
Number of base digits in the floating point significant
Number of decimal digits, q, such that any floating point number with
q decimal digits can be rounded into a floating point number with p
radix b digits and back again without change to the q decimal digits.
Minimum negative integer such that FLT_RADIX raised to that
power minus 1 is a normalized floating-point number.
Minimum negative integer such that 10 raised to that power is in the
range of normalized floating-point numbers.
Maximum negative integer such that FLT_RADIX raised to that
power minus 1 is a representable finite floating-point number.
Maximum negative integer such that 10 raised to that power is in the
range of representable finite floating-point numbers.
Maximum representable finite floating point number.
The difference between 1 and the least value greater than 1 that is
representable in the given floating point type.
Minimum normalized positive floating point number.
limits.h
limits.h
CHAR_BIT:
SCHAR_MIN:
SCHAR_MAX:
UCHAR_MAX:
CHAR_MIN:
CHAR_MAX:
MB_LEN_MAX:
SHRT_MIN:
SHRT_MAX:
USHRT_MAX:
INT_MIN:
INT_MAX:
UINT_MAX:
LONG_MIN:
LONG_MAX:
ULONG_MAX:
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Number of bits for the smallest object that is not a bit_field.
Minimum value for an object of type signed char
Maximum value for an object of type signed char
Maximum value for an object of type unsigned char
Minimum value for an object of type char(unsigned)
Maximum value for an object of type char(unsigned)
Maximum number of bytes in a multibyte character.
Minimum value for an object of type short int
Maximum value for an object of type short int
Maximum value for an object of type unsigned short int
Minimum value for an object of type signed int
Maximum value for an object of type signed int
Maximum value for an object of type unsigned int
Minimum value for an object of type signed long int
Maximum value for an object of type signed long int
Maximum value for an object of type unsigned long int
Standard C Include Files
locale.h
locale.h
locale.h
lconv
SETLOCALE()
LOCALCONV()
(Localization not supported)
localization structure
returns null
returns clocale
setjmp.h
setjmp.h
jmp_buf:
setjmp:
longjmp:
An array used by the following functions
Marks a return point for the next longjmp
Jumps to the last marked point
stddef.h
stddef.h
ptrdiff_t:
size_t:
wchar_t
NULL
The basic type of a pointer
The type of the sizeof operator (int)
The type of the largest character set supported (char) (8 bits)
A null pointer (0)
stdio.h
stdio.h
stderr
stdout
stdin
The standard error s stream (USE RS232 specified as stream or the first USE RS232)
The standard output stream (USE RS232 specified as stream last USE RS232)
The standard input s stream (USE RS232 specified as stream last USE RS232)
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stdlib.h
stdlib.h
div_t
ldiv_t
EXIT_FAILURE
EXIT_SUCCESS
RAND_MAXMBCUR_MAXSYSTEM()
Multibyte character
and string
functions:
MBLEN()
MBTOWC()
WCTOMB()
MBSTOWCS()
WBSTOMBS()
structure type that contains two signed integers(quot and rem).
structure type that contains two signed longs(quot and rem
returns 1
returns 0
1
Returns 0( not supported)
Multibyte characters not supported
Returns the length of the string.
Returns 1.
Returns 1.
Returns length of string.
Returns length of string.
Stdlib.h functions included just for compliance with ANSI C.
280
ERROR MESSAGES
Compiler Error Messages
#ENDIF with no corresponding #IF
Compiler found a #ENDIF directive without a corresponding #IF.
#ERROR
A #DEVICE required before this line
The compiler requires a #device before it encounters any statement or compiler directive that may
cause it to generate code. In general #defines may appear before a #device but not much more.
ADDRESSMOD function definition is incorrect
ADDRESSMOD range is invalid
A numeric expression must appear here
Some C expression (like 123, A or B+C) must appear at this spot in the code. Some expression
that will evaluate to a value.
Arrays of bits are not permitted
Arrays may not be of SHORT INT. Arrays of Records are permitted but the record size is always
rounded up to the next byte boundary.
Assignment invalid: value is READ ONLY
Attempt to create a pointer to a constant
Constant tables are implemented as functions. Pointers cannot be created to functions. For example
CHAR CONST MSG[9]={"HI THERE"}; is permitted, however you cannot use &MSG. You can only
reference MSG with subscripts such as MSG[i] and in some function calls such as Printf and STRCPY.
Attributes used may only be applied to a function (INLINE or SEPARATE)
An attempt was made to apply #INLINE or #SEPARATE to something other than a function.
Bad ASM syntax
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Bad expression syntax
This is a generic error message. It covers all incorrect syntax.
Baud rate out of range
The compiler could not create code for the specified baud rate. If the internal UART is being used
the combination of the clock and the UART capabilities could not get a baud rate within 3% of the
requested value. If the built in UART is not being used then the clock will not permit the indicated
baud rate. For fast baud rates, a faster clock will be required.
BIT variable not permitted here
Addresses cannot be created to bits. For example &X is not permitted if X is a SHORT INT.
Branch out of range
Cannot change device type this far into the code
The #DEVICE is not permitted after code is generated that is device specific. Move the #DEVICE
to an area before code is generated.
Character constant constructed incorrectly
Generally this is due to too many characters within the single quotes. For example 'ab' is an error
as is '\nr'. The backslash is permitted provided the result is a single character such as '\010' or '\n'.
Constant out of the valid range
This will usually occur in inline assembly where a constant must be within a particular range and it
is not. For example BTFSC 3,9 would cause this error since the second operand must be from 0-8.
Data item too big
Define expansion is too large
A fully expanded DEFINE must be less than 255 characters. Check to be sure the DEFINE is not
recursively defined.
Define syntax error
This is usually caused by a missing or misplaced (or) within a define.
Demo period has expired
Please contact CCS to purchase a licensed copy.
www.ccsinfo.com/pricing
Different levels of indirection
This is caused by a INLINE function with a reference parameter being called with a parameter that
is not a variable. Usually calling with a constant causes this.
282
Error Messages
Divide by zero
An attempt was made to divide by zero at compile time using constants.
Duplicate case value
Two cases in a switch statement have the same value.
Duplicate DEFAULT statements
The DEFAULT statement within a SWITCH may only appear once in each SWITCH. This error
indicates a second DEFAULT was encountered.
Duplicate function
A function has already been defined with this name. Remember that the compiler is not case
sensitive unless a #CASE is used.
Duplicate Interrupt Procedure
Only one function may be attached to each interrupt level. For example the #INT_RB may only
appear once in each program.
Duplicate USE
Some USE libraries may only be invoked once since they apply to the entire program such as
#USE DELAY. These may not be changed throughout the program.
Element is not a member
A field of a record identified by the compiler is not actually in the record. Check the identifier spelling.
ELSE with no corresponding IF
Compiler found an ELSE statement without a corresponding IF. Make sure the ELSE statement
always match with the previous IF statement.
End of file while within define definition
The end of the source file was encountered while still expanding a define. Check for a missing ).
End of source file reached without closing comment */ symbol
The end of the source file has been reached and a comment (started with /*) is still in effect. The */
is missing.
type are INT and CHAR.
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Expect ;
Expect }
Expect CASE
Expect comma
Expect WHILE
Expecting *
Expecting :
Expecting <
Expecting =
Expecting >
Expecting a (
Expecting a , or )
Expecting a , or }
Expecting a .
Expecting a ; or ,
Expecting a ; or {
Expecting a close paren
Expecting a declaration
Expecting a structure/union
Expecting a variable
Expecting an =
Expecting a ]
Expecting a {
Expecting an array
Expecting an identifier
Expecting function name
Expecting an opcode mnemonic
This must be a Microchip mnemonic such as MOVLW or BTFSC.
Expecting LVALUE such as a variable name or * expression
This error will occur when a constant is used where a variable should be. For example 4=5; will
give this error.
Expecting a basic type
Examples of a basic type are INT and CHAR.
Expression must be a constant or simple variable
The indicated expression must evaluate to a constant at compile time. For example 5*3+1 is
permitted but 5*x+1 where X is a INT is not permitted. If X were a DEFINE that had a constant
value then it is permitted.
Expression must evaluate to a constant
The indicated expression must evaluate to a constant at compile time. For example 5*3+1 is
permitted but 5*x+1 where X is a INT is not permitted. If X were a DEFINE that had a constant
value then it is permitted.
284
Error Messages
Expression too complex
This expression has generated too much code for the compiler to handle for a single expression.
This is very rare but if it happens, break the expression up into smaller parts.
Too many assembly lines are being generated for a single C statement. Contact CCS to increase
the internal limits.
EXTERNal symbol not found
EXTERNal symbol type mis-match
Extra characters on preprocessor command line
Characters are appearing after a preprocessor directive that do not apply to that directive.
Preprocessor commands own the entire line unlike the normal C syntax. For example the
following is an error:
#PRAGMA DEVICE main() { int x; x=1;}
File cannot be opened
Check the filename and the current path. The file could not be opened.
File cannot be opened for write
The operating system would not allow the compiler to create one of the output files. Make sure the file is
not marked READ ONLY and that the compiler process has write privileges to the directory and file.
Filename must start with " or <
The correct syntax of a #include is one of the following two formats:
#include "filename.ext"
#include
This error indicates neither a " or < was found after #include.
Filename must terminate with " or; msg:' '
The filename specified in a #include must terminate with a " if it starts with a ". It must terminate
with a > if it starts with a <.
Floating-point numbers not supported for this operation
A floating-point number is not permitted in the operation near the error. For example, ++F where F
is a float is not allowed.
Function definition different from previous definition
This is a mis-match between a function prototype and a function definition. Be sure that if a
#INLINE or #SEPARATE are used that they appear for both the prototype and definition. These
directives are treated much like a type specifier.
Function used but not defined
The indicated function had a prototype but was never defined in the program.
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Identifier is already used in this scope
An attempt was made to define a new identifier that has already been defined.
Illegal C character in input file
A bad character is in the source file. Try deleting the line and re-typing it.
Import error
Improper use of a function identifier
Function identifiers may only be used to call a function. An attempt was made to otherwise
reference a function. A function identifier should have a ( after it.
Incorrectly constructed label
This may be an improperly terminated expression followed by a label. For example:
x=5+
MPLAB:
Initialization of unions is not permitted
Structures can be initialized with an initial value but UNIONS cannot be.
Internal compiler limit reached
The program is using too much of something. An internal compiler limit was reached. Contact CCS
and the limit may be able to be expanded.
Internal Error - Contact CCS
This error indicates the compiler detected an internal inconsistency. This is not an error with the
source code; although, something in the source code has triggered the internal error. This problem
can usually be quickly corrected by sending the source files to CCS so the problem can be recreated and corrected.
In the meantime if the error was on a particular line, look for another way to perform the same
operation. The error was probably caused by the syntax of the identified statement. If the error was the
last line of the code, the problem was in linking. Look at the call tree for something out of the ordinary.
Interrupt handler uses too much stack
Too many stack locations are being used by an interrupt handler.
Invalid conversion from LONG INT to INT
In this case, a LONG INT cannot be converted to an INT. You can type cast the LONG INT to
perform a truncation. For example:
I = INT(LI);
Invalid interrupt directive
286
Error Messages
Invalid parameters to built in function
Built-in shift and rotate functions (such as SHIFT_LEFT) require an expression that evaluates to a
constant to specify the number of bytes.
Invalid Pre-Processor directive
The compiler does not know the preprocessor directive. This is the identifier in one of the following
two places:
#xxxxx
#PRAGMA xxxxx
Invalid ORG range
The end address must be greater than or equal to the start address. The range may not overlap
another range. The range may not include locations 0-3. If only one address is specified it must
match the start address of a previous #org.
Invalid overload function
Invalid type conversion
Label not permitted here
Library in USE not found
The identifier after the USE is not one of the pre-defined libraries for the compiler. Check the spelling.
Linker Error: "%s" already defined in "%s"
Linker Error: ("%s'
Linker Error: Canont allocate memory for the section "%s" in the module "%s", because it
overlaps with other sections.
Linker Error: Cannot find unique match for symbol "%s"
Linker Error: Cannot open file "%s"
Linker Error: COFF file "%s" is corrupt; recompile module.
Linker Error: Not enough memory in the target to reallocate the section "%s" in the module "%s".
Linker Error: Section "%s" is found in the modules "%s" and "%s" with different section types.
Linker Error: Unknown error, contact CCS support.
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Linker Error: Unresolved external symbol "%s" inside the module "%s".
Linker option no compatible with prior options.
Linker Warning: Section "%s" in module "%s" is declared as shared but there is no shared
memory in the target chip. The shared flag is ignored.
Linker option not compatible with prior options
Conflicting linker options are specified. For example using both the EXCEPT= and ONLY= options
in the same directive is not legal.
LVALUE required
This error will occur when a constant is used where a variable should be. For example 4=5; will
give this error.
Macro identifier requires parameters
A #DEFINE identifier is being used but no parameters were specified, as required. For example:
#define min(x,y) ((x may only be used after a pointer to a structure. It cannot be used on a structure itself or other
kind of variable.
Printf format type is invalid
An unknown character is after the % in a printf. Check the printf reference for valid formats.
Printf format (%) invalid
A bad format combination was used. For example, %lc.
Printf variable count (%) does not match actual count
The number of % format indicators in the printf does not match the actual number of variables that
follow. Remember in order to print a single %, you must use %%.
Recursion not permitted
The linker will not allow recursive function calls. A function may not call itself and it may not call
any other function that will eventually re-call it.
Recursively defined structures not permitted
A structure may not contain an instance of itself.
Reference arrays are not permitted
A reference parameter may not refer to an array.
Return not allowed in void function
A return statement may not have a value if the function is void.
RTOS call only allowed inside task functions
Selected part does not have ICD debug capability
STDOUT not defined (may be missing #RS 232)
An attempt was made to use a I/O function such as printf when no default I/O stream has been
established. Add a #USE RS232 to define a I/O stream.
Stream must be a constant in the valid range
I/O functions like fputc, fgetc require a stream identifier that was defined in a #USE RS232. This
identifier must appear exactly as it does when it was defined. Be sure it has not been redefined with
a #define.
String too long
290
Error Messages
Structure field name required
A structure is being used in a place where a field of the structure must appear. Change to the form
s.f where s is the structure name and f is a field name.
Structures and UNIONS cannot be parameters (use * or &)
A structure may not be passed by value. Pass a pointer to the structure using &.
Subscript out of range
A subscript to a RAM array must be at least 1 and not more than 128 elements. Note that large
arrays might not fit in a bank. ROM arrays may not occupy more than 256 locations.
This linker function is not available in this compiler version.
Some linker functions are only available if the PCW or PCWH product is installed.
This type cannot be qualified with this qualifier
Check the qualifiers. Be sure to look on previous lines. An example of this error is:
VOID X;
Too many array subscripts
Arrays are limited to 5 dimensions.
Too many constant structures to fit into available space
Available space depends on the chip. Some chips only allow constant structures in certain places.
Look at the last calling tree to evaluate space usage. Constant structures will appear as functions
with a @CONST at the beginning of the name.
Too many elements in an ENUM
A max of 256 elements are allowed in an ENUM.
Too many fast interrupt handlers have been defined
Too many fast interrupt handlers have been identified
Too many nested #INCLUDEs
No more than 10 include files may be open at a time.
Too many parameters
More parameters have been given to a function than the function was defined with.
Too many subscripts
More subscripts have been given to an array than the array was defined with.
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Type is not defined
The specified type is used but not defined in the program. Check the spelling.
Type specification not valid for a function
This function has a type specifier that is not meaningful to a function.
Undefined identifier
Undefined label that was used in a GOTO
There was a GOTO LABEL but LABEL was never encountered within the required scope. A GOTO
cannot jump outside a function.
Unknown device type
A #DEVICE contained an unknown device. The center letters of a device are always C regardless
of the actual part in use. For example, use PIC16C74 not PIC16RC74. Be sure the correct
compiler is being used for the indicated device. See #DEVICE for more information.
Unknown keyword in #FUSES
Check the keyword spelling against the description under #FUSES.
Unknown linker keyword
The keyword used in a linker directive is not understood.
Unknown type
The specified type is used but not defined in the program. Check the spelling.
User aborted compilation
USE parameter invalid
One of the parameters to a USE library is not valid for the current environment.
USE parameter value is out of range
One of the values for a parameter to the USE library is not valid for the current environment.
Variable never used
Variable of this data type is never greater than this constant
292
COMPILER WARNING MESSAGES
Compiler Warning Messages
#error/warning
Assignment inside relational expression
Although legal it is a common error to do something like if(a=b) when it was intended to do if(a==b).
Assignment to enum is not of the correct type.
This warning indicates there may be such a typo in this line:
Assignment to enum is not of the correct type
If a variable is declared as a ENUM it is best to assign to the variables only elements of the enum.
For example:
enum colors {RED,GREEN,BLUE} color;
...
color = GREEN; // OK
color = 1;
// Warning 209
color = (colors)1; //OK
Code has no effect
The compiler can not discern any effect this source code could have on the generated code. Some
examples:
1;
a==b;
1,2,3;
Condition always FALSE
This error when it has been determined at compile time that a relational expression will never be
true. For example:
int x;
if( x>>9 )
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Condition always TRUE
This error when it has been determined at compile time that a relational expression will never be
false. For example:
#define PIN_A1 41
...
if( PIN_A1 )
// Intended was: if( input(PIN_A1) )
Function not void and does not return a value
Functions that are declared as returning a value should have a return statement with a value to be
returned. Be aware that in C only functions declared VOID are not intended to return a value. If
nothing is specified as a function return value "int" is assumed.
Duplicate #define
The identifier in the #define has already been used in a previous #define. To redefine an identifier
use #UNDEF first. To prevent defines that may be included from multiple source do something
like:
#ifndef ID
#define ID text
#endif
Feature not supported
Function never called
Function not void and does not return a value.
Info:
Interrupt level changed
Interrupts disabled during call to prevent re-entrancy.
Linker Warning: "%s" already defined in object "%s"; second definition ignored.
Linker Warning: Address and size of section "%s" in module "%s" exceeds maximum range
for this processor. The section will be ignored.
Linker Warning: The module "%s" doesn't have a valid chip id. The module will be
considered for the target chip "%s".
Linker Warning: The target chip "%s" of the imported module "%s" doesn't match the target
chip "%s" of the source.
Linker Warning: Unsupported relocation type in module "%s".
Memory not available at requested location.
294
Compiler Warning Messages
Operator precedence rules may not be as intended, use() to clarify
Some combinations of operators are confusing to some programmers. This warning is issued for
expressions where adding() would help to clarify the meaning. For example:
if( x << n + 1 )
would be more universally understood when expressed:
if( x << (n + 1) )
Option may be wrong
Structure passed by value
Structures are usually passed by reference to a function. This warning is generated if the structure
is being passed by value. This warning is not generated if the structure is less than 5 bytes. For
example:
void myfunct( mystruct s1 ) // Pass by value - Warning
myfunct( s2 );
void myfunct( mystruct * s1 ) // Pass by reference - OK
myfunct( &s2 );
void myfunct( mystruct & s1 ) // Pass by reference - OK
myfunct( s2 );
Undefined identifier
The specified identifier is being used but has never been defined. Check the spelling.
Unprotected call in a #INT_GLOBAL
The interrupt function defined as #INT_GLOBAL is intended to be assembly language or very
simple C code. This error indicates the linker detected code that violated the standard memory
allocation scheme. This may be caused when a C function is called from a #INT_GLOBAL
interrupt handler.
Unreachable code
Code included in the program is never executed. For example:
if(n==5)
goto do5;
goto exit;
if(n==20)
// No way to get to this line
return;
Unsigned variable is never less than zero
Unsigned variables are never less than 0. This warning indicates an attempt to check to see if an
unsigned variable is negative. For example the following will not work as intended:
int i;
for(i=10; i>=0; i--)
Variable assignment never used.
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Variable of this data type is never greater than this constant
A variable is being compared to a constant. The maximum value of the variable could never be
larger than the constant. For example the following could never be true:
int x; // 8 bits, 0-255
if ( x>300)
Variable never used
A variable has been declared and never referenced in the code.
Variable used before assignment is made.
296
COMMON QUESTIONS AND ANSWERS
How are type conversions handled?
The compiler provides automatic type conversions when an assignment is performed. Some
information may be lost if the destination can not properly represent the source. For example:
int8var = int16var; Causes the top byte of int16var to be lost.
Assigning a smaller signed expression to a larger signed variable will result in the sign being
maintained. For example, a signed 8 bit int that is -1 when assigned to a 16 bit signed variable is
still -1.
Signed numbers that are negative when assigned to a unsigned number will cause the 2's
complement value to be assigned. For example, assigning -1 to a int8 will result in the int8 being
255. In this case the sign bit is not extended (conversion to unsigned is done before conversion to
more bits). This means the -1 assigned to a 16 bit unsigned is still 255.
Likewise assigning a large unsigned number to a signed variable of the same size or smaller will
result in the value being distorted. For example, assigning 255 to a signed int8 will result in -1.
The above assignment rules also apply to parameters passed to functions.
When a binary operator has operands of differing types then the lower order operand is converted
(using the above rules) to the higher. The order is as follows:
•
Float
•
Signed 32 bit
•
Unsigned 32 bit
•
Signed 16 bit
•
Unsigned 16 bit
•
Signed 8 bit
•
Unsigned 8 bit
•
1 bit
The result is then the same as the operands. Each operator in an expression is evaluated
independently. For example:
i32 = i16 - (i8 + i8)
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The + operator is 8 bit, the result is converted to 16 bit after the addition and the - is 16 bit, that
result is converted to 32 bit and the assignment is done. Note that if i8 is 200 and i16 is 400 then
the result in i32 is 256. (200 plus 200 is 144 with a 8 bit +)
Explicit conversion may be done at any point with (type) inserted before the expression to be
converted. For example in the above the perhaps desired effect may be achieved by doing:
i32 = i16 - ((long)i8 + i8)
In this case the first i8 is converted to 16 bit, then the add is a 16 bit add and the second i8 is
forced to 16 bit.
A common C programming error is to do something like:
i16 = i8 * 100;
When the intent was:
i16 = (long) i8 * 100;
Remember that with unsigned ints (the default for this compiler) the values are never negative. For
example 2-4 is 254 (in 8 bit). This means the following is an endless loop since i is never less than
0:
int i;
for( i=100; i>=0; i--)
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COMMON QUESTIONS AND ANSWERS
How can a constant data table be placed in ROM?
The compiler has support for placing any data structure into the device ROM as a constant readonly element. Since the ROM and RAM data paths are separate in the PIC®, there are restrictions
on how the data is accessed. For example, to place a 10 element BYTE array in ROM use:
BYTE CONST TABLE [10]= {9,8,7,6,5,4,3,2,1,0};
and to access the table use:
x = TABLE [i];
OR
x = TABLE [5];
BUT NOT
ptr = &TABLE [i];
In this case, a pointer to the table cannot be constructed.
Similar constructs using CONST may be used with any data type including structures, longs and
floats.
Note that in the implementation of the above table, a function call is made when a table is accessed
with a subscript that cannot be evaluated at compile time.
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How can I use two or more RS-232 ports on one PIC®?
The #USE RS232 (and I2C for that matter) is in effect for GETC, PUTC, PRINTF and KBHIT
functions encountered until another #USE RS232 is found.
The #USE RS232 is not an executable line. It works much like a #DEFINE.
The following is an example program to read from one RS-232 port (A) and echo the data to both
the first RS-232 port (A) and a second RS-232 port (B).
#USE RS232(BAUD=9600, XMIT=PIN_B0, RCV=PIN_B1)
void put_to_a( char c ) {
put(c);
}
char get_from_a( ) {
return(getc()); }
#USE RS232(BAUD=9600, XMIT=PIN_B2,RCV=PIN_B3)
void put_to_b( char b ) {
putc(c);
}
main() {
char c;
put_to_a("Online\n\r");
put_to_b("Online\n\r");
while(TRUE) {
c=get_from_a();
put_to_b(c);
put_to_a(c);
}
}
The following will do the same thing but is more readable and is the recommended method:
#USE RS232(BAUD=9600, XMIT=PIN_B0, RCV=PIN_B1, STREAM=COM_A)
#USE RS232(BAUD=9600, XMIT=PIN_B2, RCV=PIN_B3, STREAM=COM_B)
main() {
char c;
fprintf(COM_A,"Online\n\r");
fprintf(COM_B,"Online\n\r");
while(TRUE) {
c = fgetc(COM_A);
fputc(c, COM_A);
fputc(c, COM_B);
}
}
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COMMON QUESTIONS AND ANSWERS
How can the RB interrupt be used to detect a button press?
The RB interrupt will happen when there is any change (input or output) on pins B4-B7. There is
only one interrupt and the PIC® does not tell you which pin changed. The programmer must
determine the change based on the previously known value of the port. Furthermore, a single
button press may cause several interrupts due to bounce in the switch. A debounce algorithm will
need to be used. The following is a simple example:
#int_rb
rb_isr() {
byte changes;
changes = last_b ^ port_b;
last_b = port_b;
if (bit_test(changes,4 )&& !bit_test(last_b,4)){
//b4 went low
}
if (bit_test(changes,5)&& !bit_test (last_b,5)){
//b5 went low
}
.
.
.
delay_ms (100); //debounce
}
The delay=ms (100) is a quick and dirty debounce. In general, you will not want to sit in an ISR for
100 MS to allow the switch to debounce. A more elegant solution is to set a timer on the first
interrupt and wait until the timer overflows. Don't process further changes on the pin.
How do I do a printf to a string?
The following is an example of how to direct the output of a printf to a string. We used the \f to
indicate the start of the string.
This example shows how to put a floating point number in a string.
main() {
char string[20];
float f;
f=12.345;
sprintf(string,"\f%6.3f",f);
}
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How do I directly read/write to internal registers?
A hardware register may be mapped to a C variable to allow direct read and write capability to the
register. The following is an example using the TIMER0 register:
#BYTE timer0 = 0x01
timer0= 128; //set timer0 to 128
while (timer0 ! = 200); // wait for timer0 to reach 200
Bits in registers may also be mapped as follows:
#BIT T0IF = 0x0B.2
.
.
.
while (!T0IF); //wait for timer0 interrupt
Registers may be indirectly addressed as shown in the following example:
printf ("enter address:");
a = gethex ();
printf ("\r\n value is %x\r\n", *a);
The compiler has a large set of built-in functions that will allow one to perform the most common
tasks with C function calls. When possible, it is best to use the built-in functions rather than directly
write to registers. Register locations change between chips and some register operations require a
specific algorithm to be performed when a register value is changed. The compiler also takes into
account known chip errata in the implementation of the built-in functions. For example, it is better
to do set_tris_A(0); rather than *0x85=0;
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COMMON QUESTIONS AND ANSWERS
How do I get getc() to timeout after a specified time?
GETC will always wait for the character to become available. The trick is to not call getc() until a
character is ready. This can be determined with kbhit().
The following is an example of how to time out of waiting for an RS232 character.
Note that without a hardware UART the delay_us should be less than a tenth of a bit time (10 us at
9600 baud). With hardware you can make it up to 10 times the bit time. (1000 us at 9600 baud).
Use two counters if you need a timeout value larger than 65535.
short timeout_error;
char timed_getc() {
long timeout;
timeout_error=FALSE;
timeout=0;
while(!kbhit&&(++timeout<50000))
delay_us(10);
if(kbhit())
return(getc());
else {
timeout_error=TRUE;
return(0);
}
// 1/2 second
}
How do I make a pointer to a function?
The compiler does not permit pointers to functions so that the compiler can know at compile time
the complete call tree. This is used to allocate memory for full RAM re-use. Functions that could not
be in execution at the same time will use the same RAM locations. In addition since there is no
data stack in the PIC®, function parameters are passed in a special way that requires knowledge at
compile time of what function is being called. Calling a function via a pointer will prevent knowing
both of these things at compile time. Users sometimes will want function pointers to create a state
machine. The following is an example of how to do this without pointers:
enum tasks {taskA, taskB, taskC};
run_task(tasks task_to_run) {
switch(task_to_run) {
case taskA : taskA_main(); break;
case taskB : taskB_main(); break;
case taskC : taskC_main(); break;
}
}
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How do I put a NOP at location 0 for the ICD?
The CCS compilers are fully compatible with Microchips ICD debugger using MPLAB. In order to
prepare a program for ICD debugging (NOP at location 0 and so on) you need to add a #DEVICE
ICD=TRUE after your normal #DEVICE.
For example:
#INCLUDE <16F877.h>
#DEVICE ICD=TRUE
How do I write variables to EEPROM that are not a byte?
The following is an example of how to read and write a floating point number from/to EEPROM.
The same concept may be used for structures, arrays or any other type.
•
•
•
n is an offset into the EEPROM.
For floats you must increment it by 4.
For example, if the first float is at 0, the second one should be at 4, and the third
at 8.
WRITE_FLOAT_EXT_EEPROM(long int n, float data) {
int i;
for (i = 0; i < 4; i++)
write_ext_eeprom(i + n, *(((int8*)&data + i) ) ;
}
float READ_FLOAT_EXT_EEPROM(long int n) {
int i;
float data;
for (i = 0; i < 4; i++)
*(((int8*)&data) + i) = read_ext_eeprom(i + n);
return(data);
}
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COMMON QUESTIONS AND ANSWERS
How does one map a variable to an I/O port?
Two methods are as follows:
#byte
PORTB = 6 //Just an example, check the
#define ALL_OUT 0
//DATA sheet for the correct
#define ALL_IN 0xff //address for your chip
main() {
int i;
set_tris_b(ALL_OUT);
PORTB = 0;// Set all pins low
for(i=0;i<=127;++i)
// Quickly count from 0 to 127
PORTB=i;
// on the I/O port pin
set_tris_b(ALL_IN);
i = PORTB;
// i now contains the portb value.
}
Remember when using the #BYTE, the created variable is treated like memory. You must maintain
the tri-state control registers yourself via the SET_TRIS_X function. Following is an example of
placing a structure on an I/O port:
struct
port_b_layout
{int data : 4;
int rw : 1;
int cd : 1;
int enable : 1;
int reset : 1; };
struct
port_b_layout port_b;
#byte port_b = 6
struct port_b_layout const INIT_1 = {0, 1,1,1,1};
struct port_b_layout const INIT_2 = {3, 1,1,1,0};
struct port_b_layout const INIT_3 = {0, 0,0,0,0};
struct port_b_layout const FOR_SEND = {0,0,0,0,0};
// All outputs
struct
port_b_layout const FOR_READ = {15,0,0,0,0};
// Data is an input
main() {
int x;
set_tris_b((int)FOR_SEND);
// The constant
// structure is
// treated like
// a byte and
// is used to
// set the data
// direction
port_b = INIT_1;
delay_us(25);
port_b = INIT_2;
// These constant structures delay_us(25);
// are used to set all fields
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port_b = INIT_3;
// command
// on the port with a single
set_tris_b((int)FOR_READ);
port_b.rw=0;
port_b.cd=1;
port_b.enable=0;
x = port_b.data;
port_b.enable=0
// Here the individual
// fields are accessed
// independently.
}
How does the compiler determine TRUE and FALSE on expressions?
When relational expressions are assigned to variables, the result is always 0 or 1.
For example:
bytevar = 5>0;
bytevar = 0>5;
//bytevar will be 1
//bytevar will be 0
The same is true when relational operators are used in expressions.
For example:
bytevar = (x>y)*4;
is the same as:
if( x>y )
bytevar=4;
else
bytevar=0;
SHORT INTs (bit variables) are treated the same as relational expressions. They evaluate to 0 or
1.
When expressions are converted to relational expressions or SHORT INTs, the result will be
FALSE (or 0) when the expression is 0, otherwise the result is TRUE (or 1).
For example:
bytevar = 54;
bitvar = bytevar;
if(bytevar)
bytevar = 0;
bitvar = bytevar;
306
//bitvar will be 1 (bytevar ! = O)
//will be TRUE
//bitvar will be 0
COMMON QUESTIONS AND ANSWERS
How does the PIC® connect to a PC?
A level converter should be used to convert the TTL (0-5V_ levels that the PIC® operates with to
the RS-232 voltages (+/- 3-12V) used by the PIC®. The following is a popular configuration using
the MAX232 chip as a level converter.
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How does the PIC® connect to an I2C device?
Two I/O lines are required for I2C. Both lines must have pullup registers. Often the I2C device will
have a H/W selectable address. The address set must match the address in S/W. The example
programs all assume the selectable address lines are grounded.
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COMMON QUESTIONS AND ANSWERS
How much time do math operations take?
Unsigned 8 bit operations are quite fast and floating point is very slow. If possible consider fixed
point instead of floating point. For example instead of "float cost_in_dollars;" do "long
cost_in_cents;". For trig formulas consider a lookup table instead of real time calculations (see
EX_SINE.C for an example). The following are some rough times on a 20 mhz, 14-bit PIC®. Note
times will vary depending on memory banks used.
20 mhz PIC16
int8
[us]
int16
[us]
int32
[us]
float
[us]
+
0.6
1.4
3
111.
-
0.6
1.4
3
113.
*
11.1
47.2
132
178.
/
23.2
70.8
239.2
330.
exp()
*
*
*
1697.3
ln()
*
*
*
2017.7
sin()
*
*
*
2184.5
40 mhz PIC18
int8 [us]
int16 [us]
int32 [us]
float [us]
+
0.3
0.4
0.6
51.3
-
0.3
0.4
0.6
52.3
*
0.4
3.2
22.2
35.8
/
11.3
32
106.6
144.9
exp()
*
*
*
510.4
ln()
*
*
*
644.8
sin()
*
*
*
698.7
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Instead of 800, the compiler calls 0. Why?
The PIC® ROM address field in opcodes is 8-10 Bits depending on the chip and specific opcode.
The rest of the address bits come from other sources. For example, on the 174 chip to call
address 800 from code in the first page you will see:
BSF
CALL
0A,3
0
The call 0 is actually 800H since Bit 11 of the address (Bit 3 of PCLATH, Reg 0A) has been set.
Instead of A0, the compiler is using register 20. Why?
The PIC® RAM address field in opcodes is 5-7 bits long, depending on the chip. The rest of the
address field comes from the status register. For example, on the 74 chip to load A0 into W you
will see:
BSF 3,5
MOVFW
20
Note that the BSF may not be immediately before the access since the compiler optimizes out the
redundant bank switches.
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COMMON QUESTIONS AND ANSWERS
What can be done about an OUT OF RAM error?
The compiler makes every effort to optimize usage of RAM. Understanding the RAM allocation can
be a help in designing the program structure. The best re-use of RAM is accomplished when local
variables are used with lots of functions. RAM is re-used between functions not active at the same
time. See the NOT ENOUGH RAM error message in this manual for a more detailed example.
RAM is also used for expression evaluation when the expression is complex. The more complex
the expression, the more scratch RAM locations the compiler will need to allocate to that
expression. The RAM allocated is reserved during the execution of the entire function but may be
re-used between expressions within the function. The total RAM required for a function is the sum
of the parameters, the local variables and the largest number of scratch locations required for any
expression within the function. The RAM required for a function is shown in the call tree after the
RAM=. The RAM stays used when the function calls another function and new RAM is allocated for
the new function. However when a function RETURNS the RAM may be re-used by another
function called by the parent. Sequential calls to functions each with their own local variables is
very efficient use of RAM as opposed to a large function with local variables declared for the entire
process at once.
Be sure to use SHORT INT (1 bit) variables whenever possible for flags and other boolean
variables. The compiler can pack eight such variables into one byte location. The compiler does
this automatically whenever you use SHORT INT. The code size and ROM size will be smaller.
Finally, consider an external memory device to hold data not required frequently. An external 8 pin
EEPROM or SRAM can be connected to the PIC® with just 2 wires and provide a great deal of
additional storage capability. The compiler package includes example drivers for these devices.
The primary drawback is a slower access time to read and write the data. The SRAM will have fast
read and write with memory being lost when power fails. The EEPROM will have a very long write
cycle, but can retain the data when power is lost.
What is an easy way for two or more PICs® to communicate?
There are two example programs (EX_PBUSM.C and EX_PBUSR.C) that show how to use a
simple one-wire interface to transfer data between PICs®. Slower data can use pin B0 and the EXT
interrupt. The built-in UART may be used for high speed transfers. An RS232 driver chip may be
used for long distance operations. The RS485 as well as the high speed UART require 2 pins and
minor software changes. The following are some hardware configurations.
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What is the format of floating point numbers?
CCS uses the same format Microchip uses in the 14000 calibration constants. PCW users have a
utility Numeric Converter that will provide easy conversion to/from decimal, hex and float in a small
window in the Windows IDE. See EX_FLOAT.C for a good example of using floats or float types
variables. The format is as follows:
Example Number
0
1
-1
10
100
123.45
123.45E20
123.45 E-20
312
00
7F
7F
82
85
85
C8
43
00
00
80
20
48
76
27
36
00
00
00
00
00
E6
4E
2E
00
00
00
00
00
66
53
17
COMMON QUESTIONS AND ANSWERS
Why does the .LST file look out of order?
The list file is produced to show the assembly code created for the C source code. Each C source
line has the corresponding assembly lines under it to show the compiler’s work. The following
three special cases make the .LST file look strange to the first time viewer. Understanding how the
compiler is working in these special cases will make the .LST file appear quite normal and very
useful.
1. Stray code near the top of the program is sometimes under what looks like a non-executable
source line.
Some of the code generated by the compiler does not correspond to any particular source line.
The compiler will put this code either near the top of the program or sometimes under a #USE that
caused subroutines to be generated.
2. The addresses are out of order.
The compiler will create the .LST file in the order of the C source code. The linker has re-arranged
the code to properly fit the functions into the best code pages and the best half of a code page.
The resulting code is not in source order. Whenever the compiler has a discontinuity in the .LST
file, it will put a * line in the file. This is most often seen between functions and in places where
INLINE functions are called. In the case of an INLINE function, the addresses will continue in order
up where the source for the INLINE function is located.
3. The compiler has gone insane and generated the same instruction over and over.
For example:
...........A=0;
03F:
CLRF 15
*
46:CLRF 15
*
051:
CLRF 15
*
113:
CLRF 15
This effect is seen when the function is an INLINE function and is called from more than one place.
In the above case, the A=0 line is in an INLINE function called in four places. Each place it is
called from gets a new copy of the code. Each instance of the code is shown along with the
original source line, and the result may look unusual until the addresses and the * are noticed.
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Why does the compiler show less RAM than there really is?
Some devices make part of the RAM much more ineffective to access than the standard RAM. In
particular, the 509, 57, 66, 67,76 and 77 devices have this problem.
By default, the compiler will not automatically allocate variables to the problem RAM and, therefore,
the RAM available will show a number smaller than expected.
There are three ways to use this RAM:
1. Use #BYTE or #BIT to allocate a variable in this RAM. Do NOT create a pointer to these
variables.
Example:
#BYTE counter=0x30
2. Use Read_Bank and Write_Bank to access the RAM like an array. This works well if you need
to allocate an array in this RAM.
Example:
For(i=0;i<15;i++)
Write_Bank(1,i,getc());
For(i=0;i<=15;i++)
PUTC(Read_Bank(1,i));
3. You can switch to larger pointers for full RAM access (this takes more ROM). In PCB add *=8 to
the #device and in PCM/PCH add *=16 to the #device.
Example:
#DEVICE PIC16C77
or
#include <16C77.h>
#device *=16
314
*=16
COMMON QUESTIONS AND ANSWERS
Why does the compiler use the obsolete TRIS?
The use of TRIS causes concern for some users. The Microchip data sheets recommend not
using TRIS instructions for upward compatibility. If you had existing ASM code and it used TRIS
then it would be more difficult to port to a new Microchip part without TRIS. C does not have this
problem, however; the compiler has a device database that indicates specific characteristics for
every part. This includes information on whether the part has a TRIS and a list of known problems
with the part. The latter question is answered by looking at the device errata.
CCS makes every attempt to add new devices and device revisions as the data and errata sheets
become available.
PCW users can edit the device database. If the use of TRIS is a concern, simply change the
database entry for your part and the compiler will not use it.
Why is the RS-232 not working right?
1. The PIC® is Sending Garbage Characters.
A. Check the clock on the target for accuracy. Crystals are usually not a problem but RC
oscillators can cause trouble with RS-232. Make sure the #USE DELAY matches the actual
clock frequency.
B. Make sure the PC (or other host) has the correct baud and parity setting.
C. Check the level conversion. When using a driver/receiver chip, such as the MAX 232, do
not use INVERT when making direct connections with resistors and/or diodes. You
probably need the INVERT option in the #USE RS232.
D. Remember that PUTC(6) will send an ASCII 6 to the PC and this may not be a visible
character. PUTC('A') will output a visible character A.
2. The PIC® is Receiving Garbage Characters.
A. Check all of the above.
3. Nothing is Being Sent.
A. Make sure that the tri-state registers are correct. The mode (standard, fast, fixed) used
will be whatever the mode is when the #USE RS232 is encountered. Staying with the
default STANDARD mode is safest.
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B. Use the following main() for testing:
main() {
while(TRUE)
putc('U');
}
Check the XMIT pin for activity with a logic probe, scope or whatever you can. If you can
look at it with a scope, check the bit time (it should be 1/BAUD). Check again after the level
converter.
4. Nothing is being received.
First be sure the PIC® can send data. Use the following main() for testing:
main() {
printf("start");
while(TRUE)
putc( getc()+1 );
}
When connected to a PC typing A should show B echoed back.
If nothing is seen coming back (except the initial "Start"), check the RCV pin on the PIC®
with a logic probe. You should see a HIGH state and when a key is pressed at the PC, a
pulse to low. Trace back to find out where it is lost.
5. The PIC® is always receiving data via RS-232 even when none is being sent.
A. Check that the INVERT option in the USE RS232 is right for your level converter. If the
RCV pin is HIGH when no data is being sent, you should NOT use INVERT. If the pin is
low when no data is being sent, you need to use INVERT.
B. Check that the pin is stable at HIGH or LOW in accordance with A above when no data
is being sent.
C. When using PORT A with a device that supports the SETUP_ADC_PORTS function
make sure the port is set to digital inputs. This is not the default. The same is true for
devices with a comparator on PORT A.
6. Compiler reports INVALID BAUD RATE.
A. When using a software RS232 (no built-in UART), the clock cannot be really slow when
fast baud rates are used and cannot be really fast with slow baud rates. Experiment with
the clock/baud rate values to find your limits.
B. When using the built-in UART, the requested baud rate must be within 3% of a rate that
can be achieved for no error to occur. Some parts have internal bugs with BRGH set to 1
and the compiler will not use this unless you specify BRGH1OK in the #USE RS232
directive.
316
EXAMPLE PROGRAMS
EXAMPLE PROGRAMS
A large number of example programs are included with the software. The following is a list of many of
the programs and some of the key programs are re-printed on the following pages. Most programs will
work with any chip by just changing the #INCLUDE line that includes the device information. All of the
following programs have wiring instructions at the beginning of the code in a comment header. The
SIOW.EXE program included in the program directory may be used to demonstrate the example
programs. This program will use a PC COM port to communicate with the target.
Generic header files are included for the standard PIC® parts. These files are in the DEVICES
directory. The pins of the chip are defined in these files in the form PIN_B2. It is recommended that
for a given project, the file is copied to a project header file and the PIN_xx defines be changed to
match the actual hardware. For example; LCDRW (matching the mnemonic on the schematic).
Use the generic include files by placing the following in your main .C file:
#include <16C74.H>
LIST OF COMPLETE EXAMPLE PROGRAMS (in the EXAMPLES directory)
EX_14KAD.C
An analog to digital program with calibration for the PIC14000
EX_1920.C
Uses a Dallas DS1920 button to read temperature
EX_8PIN.C
Demonstrates the use of 8 pin PICs with their special I/O requirements
EX_92LCD.C
Uses a PIC16C92x chip to directly drive LCD glass
EX_AD12.C
Shows how to use an external 12 bit A/D converter
EX_ADMM.C
A/D Conversion example showing min and max analog readings
EX_ADMM10.C
Similar to ex_admm.c, but this uses 10bit A/D readings.
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C Compiler Reference Manual August 2009
EX_ADMM_STATS.C
Similar to ex_admm.c, but this uses also calculates the mean and standard deviation.
EX_BOOTLOAD.C
A stand-alone application that needs to be loaded by a bootloader (see ex_bootloader.c for a
bootloader).
EX_BOOTLOADER.C
A bootloader, loads an application onto the PIC (see ex_bootload.c for an application).
EX_CAN.C
Receive and transmit CAN packets.
EX_CHECKSUM.C
Determines the checksum of the program memory, verifies it agains the checksum that was written
to the USER ID location of the PIC.
EX_CCP1S.C
Generates a precision pulse using the PIC CCP module
EX_CCPMP.C
Uses the PIC CCP module to measure a pulse width
EX_COMP.C
Uses the analog comparator and voltage reference available on some PICs
EX_CRC.C
Calculates CRC on a message showing the fast and powerful bit operations
EX_CUST.C
Change the nature of the compiler using special preprocessor directives
EX_FIXED.C
Shows fixed point numbers
EX_DPOT.C
Controls an external digital POT
EX_DTMF.C
Generates DTMF tones
EX_ENCOD.C
Interfaces to an optical encoder to determine direction and speed
EX_EXPIO.C
Uses simple logic chips to add I/O ports to the PIC
318
EXAMPLE PROGRAMS
EX_EXSIO.C
Shows how to use a multi-port external UART chip
EX_EXTEE.C
Reads and writes to an external EEPROM
EX_EXTDYNMEM.C
Uses addressmod to create a user defined storage space, where a new qualifier is created that
reads/writes to an extrenal RAM device.
EX_FAT.C
An example of reading and writing to a FAT file system on an MMC/SD card.
EX_FLOAT.C
Shows how to use basic floating point
EX_FREQC.C
A 50 mhz frequency counter
EX_GLCD.C
Displays contents on a graphic LCD, includes shapes and text.
EX_GLINT.C
Shows how to define a custom global interrupt hander for fast interrupts
EX_HPINT.C
An example of how to use the high priority interrupts of a PIC18.
EX_HUMIDITY.C
How to read the humidity from a Humirel HT3223/HTF3223 Humidity module
EX_ICD.C
Shows a simple program for use with Microchips ICD debugger
EX_INTEE.C
Reads and writes to the PIC internal EEPROM
EX_INTFL.C
An example of how to write to the program memory of the PIC.
EX_LCDKB.C
Displays data to an LCD module and reads data for keypad
EX_LCDTH.C
Shows current, min and max temperature on an LCD
EX_LED.C
Drives a two digit 7 segment LED
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C Compiler Reference Manual August 2009
EX_LINBUS_MASTER.C
An example of how to use the LINBUS mode of a PIC's EAUSART. Talks to the
EX_LINBUS_SLAVE.C example.
EX_LINBUS_SLAVE.C
An example of how to use the LINBUS mode of a PIC's EAUSART. Talks to the
EX_LINBUS_MASTER.C example.
EX_LOAD.C
Serial boot loader program for chips like the 16F877
EX_LOGGER.C
A simple temperature data logger, uses the flash program memory for saving data
EX_MACRO.C
Shows how powerful advanced macros can be in C
EX_MALLOC.C
An example of dynamic memory allocation using malloc().
EX_MCR.C
An example of reading magnetic card readers.
EX_MMCSD.C
An example of using an MMC/SD media card as an external EEPROM. To use this card with a
FAT file system, see ex_fat.c
EX_MODBUS_MASTER.C
An example MODBUS application, this is a master and will talk to the ex_modbus_slave.c example.
EX_MODBUS_SLAVE.C
An example MODBUS application, this is a slave and will talk to the ex_modbus_master.c example.
EX_MOUSE.C
Shows how to implement a standard PC mouse on a PIC
EX_MXRAM.C
Shows how to use all the RAM on parts with problem memory allocation
EX_PATG.C
Generates 8 square waves of different frequencies
EX_PBUSM.C
Generic PIC to PIC message transfer program over one wire
EX_PBUSR.C
Implements a PIC to PIC shared RAM over one wire
320
EXAMPLE PROGRAMS
EX_PBUTT.C
Shows how to use the B port change interrupt to detect pushbuttons
EX_PGEN.C
Generates pulses with period and duty switch selectable
EX_PLL.C
Interfaces to an external frequency synthesizer to tune a radio
EX_POWER_PWM.C
How to use the enhanced PWM module of the PIC18 for motor controls.
EX_PSP.C
Uses the PIC PSP to implement a printer parallel to serial converter
EX_PULSE.C
Measures a pulse width using timer0
EX_PWM.C
Uses the PIC CCP module to generate a pulse stream
EX_QSORT.C
An example of using the stdlib function qsort() to sort data. Pointers to functions is used by qsort()
so the user can specify their sort algorithm.
EX_REACT.C
Times the reaction time of a relay closing using the CCP module
EX_RFID.C
An example of how to read the ID from a 125kHz RFID transponder tag.
EX_RMSDB.C
Calculates the RMS voltage and dB level of an AC signal
EX_RS485.C
An application that shows a multi-node communication protocol commonly found on RS-485
busses.
EX_RTC.C
Sets and reads an external Real Time Clock using RS232
EX_RTCLK.C
Sets and reads an external Real Time Clock using an LCD and keypad
EX_RTCTIMER.C
How to use the PIC's hardware timer as a real time clock.
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EX_RTOS_DEMO_X.C
9 examples are provided that show how to use CCS's built-in RTOS (Real Time Operating System).
EX_SINE.C
Generates a sine wave using a D/A converter
EX_SISR.C
Shows how to do RS232 serial interrupts
EX_STISR.C
Shows how to do RS232 transmit buffering with interrupts
EX_SLAVE.C
Simulates an I2C serial EEPROM showing the PIC slave mode
EX_SPEED.C
Calculates the speed of an external object like a model car
EX_SPI.C
Communicates with a serial EEPROM using the H/W SPI module
EX_SPI_SLAVE.C
How to use the PIC's MSSP peripheral as a SPI slave. This example will talk to the ex_spi.c example.
EX_SQW.C
Simple Square wave generator
EX_SRAM.C
Reads and writes to an external serial RAM
EX_STEP.C
Drives a stepper motor via RS232 commands and an analog input
EX_STR.C
Shows how to use basic C string handling functions
EX_STWT.C
A stop Watch program that shows how to user a timer interrupt
EX_SYNC_MASTER.C
EX_SYNC_SLAVE.C
An example of using the USART of the PIC in synchronous mode. The master and slave examples
talk to each other.
EX_TANK.C
Uses trig functions to calculate the liquid in a odd shaped tank
322
EXAMPLE PROGRAMS
EX_TEMP.C
Displays (via RS232) the temperature from a digital sensor
EX_TGETC.C
Demonstrates how to timeout of waiting for RS232 data
EX_TONES.C
Shows how to generate tones by playing "Happy Birthday"
EX_TOUCH.C
Reads the serial number from a Dallas touch device
EX_USB_HID.C
Implements a USB HID device on the PIC16C765 or an external USB chip
EX_USB_SCOPE.C
Implements a USB bulk mode transfer for a simple oscilloscope on an ext USB chip
EX_USB_KBMOUSE.C
EX_USB_KBMOUSE2.C
Examples of how to implement 2 USB HID devices on the same device, by combining a mouse and
keyboard.
EX_USB_SERIAL.C
EX_USB_SERIAL2.C
Examples of using the CDC USB class to create a virtual COM port for backwards compatability
with legacy software.
EX_VOICE.C
Self learning text to voice program
EX_WAKUP.C
Shows how to put a chip into sleep mode and wake it up
EX_WDT.C
Shows how to use the PIC watch dog timer
EX_WDT18.C
Shows how to use the PIC18 watch dog timer
EX_X10.C
Communicates with a TW523 unit to read and send power line X10 codes
EX_EXTA.C
The XTEA encryption cipher is used to create an encrypted link between two PICs.
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LIST OF INCLUDE FILES (in the DRIVERS directory)
14KCAL.C
Calibration functions for the PIC14000 A/D converter
2401.C
Serial EEPROM functions
2402.C
Serial EEPROM functions
2404.C
Serial EEPROM functions
2408.C
Serial EEPROM functions
24128.C
Serial EEPROM functions
2416.C
Serial EEPROM functions
24256.C
Serial EEPROM functions
2432.C
Serial EEPROM functions
2465.C
Serial EEPROM functions
25160.C
Serial EEPROM functions
25320.C
Serial EEPROM functions
25640.C
Serial EEPROM functions
25C080.C
Serial EEPROM functions
68HC68R1
C Serial RAM functions
324
EXAMPLE PROGRAMS
68HC68R2.C
Serial RAM functions
74165.C
Expanded input functions
74595.C
Expanded output functions
9346.C
Serial EEPROM functions
9356.C
Serial EEPROM functions
9356SPI.C
Serial EEPROM functions (uses H/W SPI)
9366.C
Serial EEPROM functions
AD7705.C
A/D Converter functions
AD7715.C
A/D Converter functions
AD8400.C
Digital POT functions
ADS8320.C
A/D Converter functions
ASSERT.H
Standard C error reporting
AT25256.C
Serial EEPROM functions
AT29C1024.C
Flash drivers for an external memory chip
CRC.C
CRC calculation functions
CE51X.C
Functions to access the 12CE51x EEPROM
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CE62X.C
Functions to access the 12CE62x EEPROM
CE67X.C
Functions to access the 12CE67x EEPROM
CTYPE.H
Definitions for various character handling functions
DS1302.C
Real time clock functions
DS1621.C
Temperature functions
DS1621M.C
Temperature functions for multiple DS1621 devices on the same bus
DS1631.C
Temperature functions
DS1624.C
Temperature functions
DS1868.C
Digital POT functions
ERRNO.H
Standard C error handling for math errors
FLOAT.H
Standard C float constants
FLOATEE.C
Functions to read/write floats to an EEPROM
INPUT.C
Functions to read strings and numbers via RS232
ISD4003.C
Functions for the ISD4003 voice record/playback chip
KBD.C
Functions to read a keypad
LCD.C
LCD module functions
326
EXAMPLE PROGRAMS
LIMITS.H
Standard C definitions for numeric limits
LMX2326.C
PLL functions
LOADER.C
A simple RS232 program loader
LOCALE.H
Standard C functions for local language support
LTC1298.C
12 Bit A/D converter functions
MATH.H
Various standard trig functions
MAX517.C
D/A converter functions
MCP3208.C
A/D converter functions
NJU6355.C
Real time clock functions
PCF8570.C
Serial RAM functions
PIC_USB.H
Hardware layer for built-in PIC USB
SC28L19X.C
Driver for the Phillips external UART (4 or 8 port)
SETJMP.H
Standard C functions for doing jumps outside functions
STDDEF.H
Standard C definitions
STDIO.H
Not much here - Provided for standard C compatibility
STDLIB.H
String to number functions
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STDLIBM.H
Standard C memory management functions
STRING.H
Various standard string functions
TONES.C
Functions to generate tones
TOUCH.C
Functions to read/write to Dallas touch devices
USB.H
Standard USB request and token handler code
USBN960X.C
Functions to interface to Nationals USBN960x USB chips
USB.C
USB token and request handler code, Also includes usb_desc.h and usb.h
X10.C
Functions to read/write X10 codes
328
EXAMPLE PROGRAMS
/////////////////////////////////////////////////////////////////
///
EX_SQW.C
///
///
This program displays a message over the RS-232 and
///
///
waits for any keypress to continue. The program
///
///
will then begin a 1khz square wave over I/O pin B0.
///
///
Change both delay_us to delay_ms to make the
///
///
frequency 1 hz. This will be more visible on
///
///
a LED. Configure the CCS prototype card as follows:
///
///
insert jumpers from 11 to 17, 12 to 18, and 42 to 47.
///
/////////////////////////////////////////////////////////////////
#ifdef __PCB__
#include <16C56.H>
#else
#include <16C84.H>
#endif
#use delay(clock=20000000)
#use rs232(baud=9600, xmit=PIN_A3, rcv=PIN_A2)
main() {
printf("Press any key to begin\n\r");
getc();
printf("1 khz signal activated\n\r");
while (TRUE) {
output_high (PIN_B0);
delay_us(500);
output_low(PIN_B0);
delay_us(500);
}
}
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/////////////////////////////////////////////////////////////////
///
EX_STWT.C
///
///
This program uses the RTCC (timer0) and interrupts
///
///
to keep a real time seconds counter. A simple stop
///
///
watch function is then implemented. Configure the
///
///
CCS prototype card as follows, insert jumpers from:
///
///
11 to 17 and 12 to 18.
///
/////////////////////////////////////////////////////////////////
#include <16C84.H>
#use delay (clock=20000000)
#use rs232(baud=9600, xmit=PIN_A3, rcv=PIN_A2_
#define INTS_PER_SECOND 76
//(20000000/(4*256*256))
byte seconds;
//Number of interrupts left
//before a second has elapsed
#int_rtcc
clock_isr() {
//This function is called
//every time the RTCC (timer0)
//overflows (255->0)
//For this program this is apx
//76 times per second.
if(--int_count==0) {
++seconds;
int_count=INTS_PER_SECOND;
}
}
main() {
byte start;
int_count=INTS_PER_SECOND;
set_rtcc(0);
setup_counters (RTCC_INTERNAL, RTCC_DIV_256);
enable_interrupts (INT_RTCC);
enable_interrupts(GLOBAL)
do {
printf ("Press any key to begin. \n\r");
getc();
start=seconds;
printf("Press any key to stop. \n\r");
getc();
printf ("%u seconds. \n\r", seconds-start);
} while (TRUE);
}
330
EXAMPLE PROGRAMS
/////////////////////////////////////////////////////////////////
///
EX_INTEE.C
///
///
This program will read and write to the ’83 or ’84
///
///
internal EEPROM. Configure the CCS prototype card as ///
///
follows: insert jumpers from 11 to 17 and 12 to 18.
///
/////////////////////////////////////////////////////////////////
#include <16C84.H>
#use delay(clock-100000000)
#use rs232 (baud=9600, xmit=PIN_A3, rv+PIN_A2)
#include
main () {
byte i,j,address, value;
do {
printf("\r\n\nEEPROM: \r\n")
//Displays contents
for(i=0; i<3; ++i) {
//entire EEPROM
for (j=0; j<=15; ++j) {
//in hex
printf("%2x", read_eeprom(i+16+j));
}
printf("\n\r");
}
printf ("\r\nlocation to change: ");
address= gethex();
printf ("\r\nNew value: ");
value=gethex();
write_eeprom (address, value);
} while (TRUE)
}
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/////////////////////////////////////////////////////////////////
///
Library for a Microchip 93C56 configured for a x8
///
///
///
///
org init_ext_eeprom();
Call before the other
///
///
functions are used
///
///
///
///
write_ext_eeprom(a,d);
Write the byte d to
///
///
the address a
///
///
///
///
d=read_ext_eeprom (a);
Read the byte d from
///
///
the address a.
///
///
The main program may define eeprom_select,
///
///
eeprom_di, eeprom_do and eeprom_clk to override
///
///
the defaults below.
///
/////////////////////////////////////////////////////////////////
#ifndef EEPROM_SELECT
#define
#define
#define
#define
EEPROM_SELECT
EEPROM_CLK
EEPROM_DI
EEPROM_DO
PIN_B7
PIN_B6
PIN_B5
PIN_B4
#endif
#define EEPROM_ADDRESS byte
#define EEPROM_SIZE
256
void init_ext_eeprom () {
byte cmd[2];
byte i;
output_low(EEPROM_DI);
output_low(EEPROM_CLK);
output_low(EEPROM_SELECT);
cmd[0]=0x80;
cmd[1]=0x9;
for (i=1; i<=4; ++i)
shift_left(cmd, 2,0);
output_high (EEPROM_SELECT);
for (i=1; i<=12; ++i) {
output_bit(EEPROM_DI, shift_left(cmd, 2,0));
output_high (EEPROM_CLK);
output_low(EEPROM_CLK);
}
output_low(EEPROM_DI);
output_low(EEPROM_SELECT);
}
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EXAMPLE PROGRAMS
void write_ext_eeprom (EEPROM_ADDRESS address, byte data)
byte cmd[3];
byte i;
{
cmd[0]=data;
cmd[1]=address;
cmd[2]=0xa;
for(i=1;i<=4;++i)
shift_left(cmd,3,0);
output_high(EEPROM_SELECT);
for(i=1;i<=20;++i) {
output_bit (EEPROM_DI, shift_left (cmd,3,0));
output_high (EEPROM_CLK);
output_low(EEPROM_CLK);
}
output_low (EEPROM_DI);
output_low (EEPROM_SELECT);
delay_ms(11);
}
byte read_ext_eeprom(EEPROM_ADDRESS address) {
byte cmd[3];
byte i, data;
cmd[0]=0;
cmd[1]=address;
cmd[2]=0xc;
for(i=1;i<=4;++i)
shift_left(cmd,3,0);
output_high(EEPROM_SELECT);
for(i=1;i<=20;++i) {
output_bit (EEPROM_DI, shift_left (cmd,3,0));
output_high (EEPROM_CLK);
output_low(EEPROM_CLK);
if (i>12)
shift_left (&data, 1, input (EEPROM_DO));
}
output_low (EEPROM_SELECT);
return(data);
}
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/////////////////////////////////////////////////////////////////
///
This file demonstrates how to use the real time
///
///
operating system to schedule tasks and how to use
///
///
the rtos_run function.
///
///
///
///
this demo makes use of the PIC18F452 prototyping board ///
/////////////////////////////////////////////////////////////////
#include <18F452.h>
#use delay(clock=20000000)
#use rs232(baud=9600,xmit=PIN_C6,rcv=PIN_C7)
// this tells the compiler that the rtos functionality will be needed, that
// timer0 will be used as the timing device, and that the minor cycle for
// all tasks will be 500 miliseconds
#use rtos(timer=0,minor_cycle=100ms)
// each function that is to be an operating system task must have the #task
// preprocessor directive located above it.
// in this case, the task will run every second, its maximum time to run is
// less than the minor cycle but this must be less than or equal to the
// minor cycle, and there is no need for a queue at this point, so no
// memory will be reserved.
#task(rate=1000ms,max=100ms)
// the function can be called anything that a standard function can be called
void The_first_rtos_task ( )
{
printf("1\n\r");
}
#task(rate=500ms,max=100ms)
void The_second_rtos_task ( )
{
printf("\t2!\n\r");
}
#task(rate=100ms,max=100ms)
void The_third_rtos_task ( )
{
printf("\t\t3\n\r");
}
// main is still the entry point for the program
void main ( )
{
// rtos_run begins the loop which will call the task functions above at the
// schedualed time
rtos_run ( );
}
334
EXAMPLE PROGRAMS
/////////////////////////////////////////////////////////////////
///
This file demonstrates how to use the real time
///
///
operating system rtos_terminate function
///
///
///
///
this demo makes use of the PIC18F452 prototyping board ///
/////////////////////////////////////////////////////////////////
#include <18F452.h>
#use delay(clock=20000000)
#use rs232(baud=9600,xmit=PIN_C6,rcv=PIN_C7)
#use rtos(timer=0,minor_cycle=100ms)
// a counter will be kept
int8 counter;
#task(rate=1000ms,max=100ms)
void The_first_rtos_task ( )
{
printf("1\n\r");
// if the counter has reached the desired value, the rtos will terminate
if(++counter==5)
rtos_terminate ( );
}
#task(rate=500ms,max=100ms)
void The_second_rtos_task ( )
{
printf("\t2!\n\r");
}
#task(rate=100ms,max=100ms)
void The_third_rtos_task ( )
{
printf("\t\t3\n\r");
}
void main ( )
{
// main is the best place to initialize resources the the rtos is dependent
// upon
counter = 0;
rtos_run ( );
// once the rtos_terminate function has been called, rtos_run will return
// program control back to main
printf("RTOS has been terminated\n\r");
}
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/////////////////////////////////////////////////////////////////
///
This file demonstrates how to use the real time
///
///
operating system rtos_enable and rtos_disable functions ///
///
///
///
this demo makes use of the PIC18F452 prototyping board ///
/////////////////////////////////////////////////////////////////
#include <18F452.h>
#use delay(clock=20000000)
#use rs232(baud=9600,xmit=PIN_C6,rcv=PIN_C7)
#use rtos(timer=0,minor_cycle=100ms)
int8 counter;
// now that task names will be passed as parameters, it is best
// to declare function prototypes so that their are no undefined
// identifier errors from the compiler
#task(rate=1000ms,max=100ms)
void The_first_rtos_task ( );
#task(rate=500ms,max=100ms)
void The_second_rtos_task ( );
#task(rate=100ms,max=100ms)
void The_third_rtos_task ( );
void The_first_rtos_task ( ) {
printf("1\n\r");
if(counter==3)
{
// to disable a task, simply pass the task name
// into the rtos_disable function
rtos_disable(The_third_rtos_task);
}
}
void The_second_rtos_task ( ) {
printf("\t2!\n\r");
if(++counter==10) {
counter=0;
// enabling tasks is similar to disabling them
rtos_enable(The_third_rtos_task);
}
}
void The_third_rtos_task ( ) {
printf("\t\t3\n\r");
}
void main ( ) {
counter = 0;
rtos_run ( );
}
336
EXAMPLE PROGRAMS
/////////////////////////////////////////////////////////////////
///
This file demonstrates how to use the real time
///
///
operating systems messaging functions
///
///
///
///
this demo makes use of the PIC18F452 prototyping board ///
/////////////////////////////////////////////////////////////////
#include <18F452.h>
#use delay(clock=20000000)
#use rs232(baud=9600,xmit=PIN_C6,rcv=PIN_C7)
#use rtos(timer=0,minor_cycle=100ms)
int8 count;
// each task will now be given a two byte queue
#task(rate=1000ms,max=100ms,queue=2)
void The_first_rtos_task ( );
#task(rate=500ms,max=100ms,queue=2)
void The_second_rtos_task ( );
void The_first_rtos_task ( ) {
// the function rtos_msg_poll will return the number of messages in the
// current tasks queue
// always make sure to check that their is a message or else the read
// function will hang
if(rtos_msg_poll ( )>0){
// the function rtos_msg_read, reads the first value in the queue
printf("messages recieved by task1 : %i\n\r",rtos_msg_read ( ));
// the funciton rtos_msg_send, sends the value given as the
// second parameter to the function given as the first
rtos_msg_send(The_second_rtos_task,count);
count++;
}
}
void The_second_rtos_task ( ) {
rtos_msg_send(The_first_rtos_task,count);
if(rtos_msg_poll ( )>0){
printf("messages recieved by task2 : %i\n\r",rtos_msg_read ( ));
count++;
}
}
void main ( ) {
count=0;
rtos_run();
}
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/////////////////////////////////////////////////////////////////
///
This file demonstrates how to use the real time
///
///
operating systems yield function
///
///
///
///
this demo makes use of the PIC18F452 prototyping board ///
/////////////////////////////////////////////////////////////////
#include <18F452.h>
#use delay(clock=20000000)
#use rs232(baud=9600,xmit=PIN_C6,rcv=PIN_C7)
#use rtos(timer=0,minor_cycle=100ms)
#task(rate=1000ms,max=100ms,queue=2)
void The_first_rtos_task ( );
#task(rate=500ms,max=100ms,queue=2)
void The_second_rtos_task ( );
void The_first_rtos_task ( ) {
int count=0;
// rtos_yield allows the user to break out of a task at a given point
// and return to the same ponit when the task comes back into context
while(TRUE){
count++;
rtos_msg_send(The_second_rtos_task,count);
rtos_yield ( );
}
}
void The_second_rtos_task ( ) {
if(rtos_msg_poll( ))
{
printf("count is : %i\n\r",rtos_msg_read ( ));
}
}
void main ( ) {
rtos_run();
}
338
EXAMPLE PROGRAMS
/////////////////////////////////////////////////////////////////
///
This file demonstrates how to use the real time
///
///
///
operating systems yield function signal and wait
function to handle resources
///
///
///
///
///
this demo makes use of the PIC18F452 prototyping board ///
/////////////////////////////////////////////////////////////////
#include <18F452.h>
#use delay(clock=20000000)
#use rs232(baud=9600,xmit=PIN_C6,rcv=PIN_C7)
#use rtos(timer=0,minor_cycle=100ms)
// a semaphore is simply a shared system resource
// in the case of this example, the semaphore will be the red LED
int8 sem;
#define RED PIN_B5
#task(rate=1000ms,max=100ms,queue=2)
void The_first_rtos_task ( );
#task(rate=1000ms,max=100ms,queue=2)
void The_second_rtos_task ( );
void The_first_rtos_task ( ) {
int i;
// this will decrement the semaphore variable to zero which signals
// that no more user may use the resource
rtos_wait(sem);
for(i=0;i<5;i++){
output_low(RED); delay_ms(20); output_high(RED);
rtos_yield ( );
}
// this will inrement the semaphore variable to zero which then signals
// that the resource is available for use
rtos_signal(sem);
}
void The_second_rtos_task ( ) {
int i;
rtos_wait(sem);
for(i=0;i<5;i++){
output_high(RED); delay_ms(20); output_low(RED);
rtos_yield ( );
}
rtos_signal(sem);
}
void main ( ) {
// sem is initialized to the number of users allowed by the resource
// in the case of the LED and most other resources that limit is one
sem=1;
rtos_run();
}
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/////////////////////////////////////////////////////////////////
///
This file demonstrates how to use the real time
///
///
operating systems await function
///
///
///
///
this demo makes use of the PIC18F452 prototyping board ///
/////////////////////////////////////////////////////////////////
#include <18F452.h>
#use delay(clock=20000000)
#use rs232(baud=9600,xmit=PIN_C6,rcv=PIN_C7)
#use rtos(timer=0,minor_cycle=100ms)
#define RED PIN_B5
#define GREEN PIN_A5
int8 count;
#task(rate=1000ms,max=100ms,queue=2)
void The_first_rtos_task ( );
#task(rate=1000ms,max=100ms,queue=2)
void The_second_rtos_task ( );
void The_first_rtos_task ( ) {
// rtos_await simply waits for the given expression to be true
// if it is not true, it acts like an rtos_yield and passes the system
// to the next task
rtos_await(count==10);
output_low(GREEN); delay_ms(20); output_high(GREEN);
count=0;
}
void The_second_rtos_task ( ) {
output_low(RED); delay_ms(20); output_high(RED);
count++;
}
void main ( ) {
count=0;
rtos_run();
}
340
EXAMPLE PROGRAMS
/////////////////////////////////////////////////////////////////
///
This file demonstrates how to use the real time
///
///
operating systems statistics features
///
///
///
///
this demo makes use of the PIC18F452 prototyping board ///
/////////////////////////////////////////////////////////////////
#include <18F452.h>
#use delay(clock=20000000)
#use rs232(baud=9600,xmit=PIN_C6,rcv=PIN_C7)
#use rtos(timer=0,minor_cycle=100ms,statistics)
// This structure must be defined inorder to retrieve the statistical
// information
struct rtos_stats {
int32 task_total_ticks;
// number of ticks the task has used
int16 task_min_ticks;
// the minimum number of ticks used
int16 task_max_ticks;
// the maximum number of ticks ueed
int16 hns_per_tick;
// us = (ticks*hns_per_tic)/10
};
#task(rate=1000ms,max=100ms)
void The_first_rtos_task ( );
#task(rate=1000ms,max=100ms)
void The_second_rtos_task ( );
void The_first_rtos_task ( ) {
struct rtos_stats stats;
rtos_stats(The_second_rtos_task,&stats);
printf ( "\n\r" );
printf ( "task_total_ticks : %Lius\n\r" ,
(int32)(stats.task_total_ticks)*stats.hns_per_tick );
printf ( "task_min_ticks
: %Lius\n\r" ,
(int32)(stats.task_min_ticks)*stats.hns_per_tick );
printf ( "task_max_ticks
: %Lius\n\r" ,
(int32)(stats.task_max_ticks)*stats.hns_per_tick );
printf ("\n\r");
}
void The_second_rtos_task ( ) {
int i, count = 0;
while(TRUE) {
if(rtos_overrun(the_second_rtos_task)) {
printf("The Second Task has Overrun\n\r\n\r");
count=0;
}
else
count++;
for(i=0;i
#use delay(clock=20000000)
#use rs232(baud=9600,xmit=PIN_C6,rcv=PIN_C7)
#use rtos(timer=0,minor_cycle=100ms)
#define RED PIN_B5
#define GREEN PIN_A5
#include
// this character array will be used to take input from the prompt
char input [ 30 ];
// this will hold the current position in the array
int index;
// this will signal to the kernal that input is ready to be processed
int1 input_ready;
// different commands
char en1 [ ] = "enable1";
char en2 [ ] = "enable2";
char dis1 [ ] = "disable1";
char dis2 [ ] = "disable2";
#task(rate=1000ms,max=100ms)
void The_first_rtos_task ( );
#task(rate=1000ms,max=100ms)
void The_second_rtos_task ( );
#task(rate=500ms,max=100ms)
void The_kernal ( );
// serial interupt
#int_rda
void serial_interrupt ( )
{
if(index<29) {
input [ index ] = getc ( );
// get the value in the serial recieve reg
putc ( input [ index ] );
// display it on the screen
if(input[index]==0x0d){
// if the input was enter
putc('\n');
input [ index ] = '\0';
// add the null character
input_ready=TRUE;
// set the input read variable to true
index=0;
// and reset the index
}
else if (input[index]==0x08){
if ( index > 1 ) {
putc(' ');
putc(0x08);
index-=2;
}
}
index++;
342
EXAMPLE PROGRAMS
}
else {
putc ( '\n' );
putc ( '\r' );
input [ index ] = '\0';
index = 0;
input_ready = TRUE;
}
}
void The_first_rtos_task ( ) {
output_low(RED); delay_ms(50); output_high(RED);
}
void The_second_rtos_task ( ) {
output_low(GREEN); delay_ms(20); output_high(GREEN);
}
void The_kernal ( ) {
while ( TRUE ) {
printf ( "INPUT:> " );
while(!input_ready)
rtos_yield ( );
printf ( "%S\n\r%S\n\r", input , en1 );
if ( !strcmp( input , en1 ) )
rtos_enable ( The_first_rtos_task );
else if ( !strcmp( input , en2 ) )
rtos_enable ( The_second_rtos_task );
else if ( !strcmp( input , dis1 ) )
rtos_disable ( The_first_rtos_task );
else if ( !strcmp ( input , dis2 ) )
rtos_disable ( The_second_rtos_task );
else
printf ( "Error: unknown command\n\r" );
input_ready=FALSE;
index=0;
}
}
void main ( ) {
// initialize input variables
index=0;
input_ready=FALSE;
// initialize interrupts
enable_interrupts(int_rda);
enable_interrupts(global);
rtos_run();
}
343
SOFTWARE LICENSE AGREEMENT
SOFTWARE LICENSE AGREEMENT
By opening the software diskette package, you agree to abide by the following provisions. If you
choose not to agree with these provisions promptly return the unopened package for a refund.
1. License- Custom Computer Services ("CCS") grants you a license to use the software program
("Licensed Materials") on a single-user computer. Use of the Licensed Materials on a network
requires payment of additional fees.
2. Applications Software- Derivative programs you create using the Licensed Materials identified
as Applications Software, are not subject to this agreement.
3. Warranty- CCS warrants the media to be free from defects in material and workmanship and
that the software will substantially conform to the related documentation for a period of thirty (30)
days after the date of your purchase. CCS does not warrant that the Licensed Materials will be free
from error or will meet your specific requirements.
4. Limitations- CCS makes no warranty or condition, either expressed or implied, including but not
limited to any implied warranties of merchantability and fitness for a particular purpose, regarding
the Licensed Materials.
Neither CCS nor any applicable licensor will be liable for an incidental or consequential damages,
including but not limited to lost profits.
5. Transfers- Licensee agrees not to transfer or export the Licensed Materials to any country other
than it was originally shipped to by CCS.
The Licensed Materials are copyrighted
© 1994-2009 Custom Computer Services Incorporated
All Rights Reserved Worldwide
P.O. Box 2452
Brookfield, WI 53008
345
Source Exif Data:
File Type : PDF File Type Extension : pdf MIME Type : application/pdf PDF Version : 1.4 Linearized : Yes Tagged PDF : Yes XMP Toolkit : Adobe XMP Core 4.0-c316 44.253921, Sun Oct 01 2006 17:14:39 Producer : Acrobat Distiller 8.1.0 (Windows) Company : ccs Source Modified : D:20090819170158 Creator Tool : Acrobat PDFMaker 8.1 for Word Modify Date : 2009:08:19 12:28:39-05:00 Create Date : 2009:08:19 12:16:11-05:00 Metadata Date : 2009:08:19 12:28:39-05:00 Document ID : uuid:bf1e330c-7cf5-4291-944e-20e36dbda9f8 Instance ID : uuid:96e3b8c3-e33f-4db1-9325-09513f669650 Subject : 27 Format : application/pdf Creator : CCS Employee Title : C Compiler Reference Manual August 2009 Page Count : 357 Page Layout : OneColumn Author : CCS EmployeeEXIF Metadata provided by EXIF.tools