CC120X Low Power High Performance Sub 1 GHz RF Transceivers (Rev. B) Cc1201 User Guide

cc1200-user-guide

cc120x-user-guide

User's%20Guide%20-%20swru346b

User Manual: Pdf

Open the PDF directly: View PDF .
Page Count: 115

Download
Open PDF In Browser	View PDF

CC120X

CC120X Low-Power High Performance
Sub-1 GHz RF Transceivers

User’s Guide

SWRU346B

Page 1 of 114

CC120X
Abbreviations
Abbreviations used in this data sheet are described below.
2-FSK

Binary Frequency Shift Keying

Local Oscillator

4-FSK

Quaternary Frequency Shift Keying

LSB

Least Significant Bit

ACP

Adjacent Channel Power

LQI

Link Quality Indicator

ADC

Analog to Digital Converter

MCU

Microcontroller Unit

AES
AFC

Advanced Encryption Standard
Automatic Frequency Compensation

MSB
MSK

Most Significant Bit
Minimum Shift Keying

AGC
ASK
BIST

Automatic Gain Control
Amplitude Shift Keying

NRNSC
OOK

Non-recursive Non-systematic Convolutional
On-Off Keying

Built-In Self-Test
Bandwidth-Time Product

PA
PD

Power Amplifier
Power Down

BT
CCA

Clear Channel Assessment

PER

Packet Error Rate

CRC

Cyclic Redundancy Check

PLL

Phase Locked Loop

CS
DC

Carrier Sense

POR

Power-On Reset

Direct Current

PQT

Preamble Quality Threshold

CFM
ESR

Custom Frequency Modulation

PTAT

Proportional to Absolute Temperature

Equivalent Series Resistance

QPSK

Quadrature Phase Shift Keying

FCC

Federal Communications Commission

Resistor-Capacitor

FEC
FIFO

Forward Error Correction

Radio Frequency

First-In-First-Out

RSSI

Received Signal Strength Indicator

FHSS

Frequency Hopping Spread Spectrum

Receive, Receive Mode

FS
GFSK

Frequency Synthesizer
Gaussian shaped Frequency Shift Keying

RXDCM
SPI

RX Duty Cycle Mode
Serial Peripheral Interface

GPIO

General Purpose Input/Output

SRD

Short Range Devices

Intermediate Frequency

Transmit, Transmit Mode

I/Q

In-Phase/Quadrature

VCO

Voltage Controlled Oscillator

ISM

Industrial, Scientific, Medical

eWOR

Enhanced Wake on Radio

kbps

kilo bit per second

XOSC

Crystal Oscillator

ksps

kilo symbol per second

XTAL

Crystal

LNA

Low Noise Amplifier

SWRU346B

Page 2 of 114

CC120X
Table of Contents
ABBREVIATIONS ............................................................................................................................................... 2
TABLE OF CONTENTS ..................................................................................................................................... 3
1
OVERVIEW.............................................................................................................................................. 5
2
CONFIGURATION SOFTWARE .......................................................................................................... 6
3
MICROCONTROLLER INTERFACE ................................................................................................. 7
3.1
CONFIGURATION ......................................................................................................................................... 7
3.2
SPI ACCESS TYPES ...................................................................................................................................... 9
3.3
OPTIONAL PIN CTRL RADIO CONTROL FEATURE .................................................................................... 17
3.4
GENERAL PURPOSE INPUT/OUTPUT CONTROL PINS .................................................................................. 17
4
ON-CHIP TEMPERATURE SENSOR ................................................................................................ 22
5
COMMON RECEIVE AND TRANSMIT CONFIGURATIONS ...................................................... 23
5.1
DATA COMMUNICATION MODES ............................................................................................................... 23
5.2
MODULATION FORMATS............................................................................................................................ 24
5.3
FORWARD ERROR CORRECTION ................................................................................................................ 29
5.4
SYMBOL RATE PROGRAMMING ................................................................................................................. 29
6
RECEIVE CONFIGURATION ............................................................................................................ 30
6.1
RX FILTER BANDWIDTH ............................................................................................................................ 30
6.2
DC OFFSET REMOVAL ............................................................................................................................... 31
6.3
FEEDBACK TO PLL .................................................................................................................................... 32
6.4
AUTOMATIC GAIN CONTROL ..................................................................................................................... 33
6.5
IMAGE COMPENSATION ............................................................................................................................. 34
6.6
BIT SYNCHRONIZATION ............................................................................................................................. 35
6.7
BYTE SYNCHRONIZATION, SYNC WORD DETECTION................................................................................. 35
6.8
PREAMBLE DETECTION ............................................................................................................................. 36
6.9
RSSI .......................................................................................................................................................... 37
6.10 COLLISION DETECTOR ............................................................................................................................... 42
6.11 CLEAR CHANNEL ASSESSMENT (CCA) ..................................................................................................... 42
6.12 LISTEN BEFORE TALK (LBT) .................................................................................................................... 43
6.13 LINK QUALITY INDICATOR (LQI) .............................................................................................................. 43
7
TRANSMIT CONFIGURATION ......................................................................................................... 44
7.1
PA OUTPUT POWER PROGRAMMING ......................................................................................................... 44
7.2
OOK/ASK BIT SHAPING ........................................................................................................................... 45
8
PACKET HANDLING HARDWARE SUPPORT .............................................................................. 46
8.1
STANDARD PACKET FORMAT .................................................................................................................... 46
8.2
PACKET FILTERING IN RECEIVE MODE ...................................................................................................... 52
8.3
PACKET HANDLING IN TRANSMIT MODE ................................................................................................... 53
8.4
PACKET HANDLING IN RECEIVE MODE ..................................................................................................... 53
8.5
PACKET HANDLING IN FIRMWARE ............................................................................................................. 53
8.6
TX FIFO AND RX FIFO ............................................................................................................................ 54
8.7
IEEE 802.15.4G SUPPORT ......................................................................................................................... 55
8.8
802.15.4G FRAME CHECK SEQUENCE (FCS) ............................................................................................. 59
8.9
TRANSPARENT AND SYNCHRONOUS SERIAL OPERATION .......................................................................... 59
9
RADIO CONTROL ................................................................................................................................ 62
9.1
POWER-ON START-UP SEQUENCE ............................................................................................................. 62
9.2
CRYSTAL CONTROL ................................................................................................................................... 62
9.3
VOLTAGE REGULATOR CONTROL.............................................................................................................. 62
9.4
ACTIVE MODES ......................................................................................................................................... 63
9.5
RX TERMINATION ..................................................................................................................................... 64
9.6
ENHANCED WAKE ON RADIO (EWOR) ...................................................................................................... 67
9.7
RX SNIFF MODE ........................................................................................................................................ 70
9.8
RX DUTY CYCLE MODE ............................................................................................................................ 72
9.9
RC OSCILLATOR CALIBRATION ................................................................................................................. 73
9.10 ANTENNA DIVERSITY AND MULTIPLE PATH TRANSMISSION ..................................................................... 73
9.11 RANDOM NUMBER GENERATOR ................................................................................................................ 74
9.12 RF PROGRAMMING .................................................................................................................................... 74
9.13 FREQUENCY SYNTHESIZER CONFIGURATION............................................................................................. 75

SWRU346B

Page 3 of 114

CC120X
9.14
9.15
9.16
10
10.1
10.2
10.3
10.4
11
11.1
11.2
11.3
11.4
11.5
12
13
14
15
16
16.1

IF PROGRAMMING ..................................................................................................................................... 75
FS CALIBRATION ....................................................................................................................................... 76
FS OUT OF LOCK DETECTION .................................................................................................................... 76
AES .......................................................................................................................................................... 77
AES BLOCK OPERATION ........................................................................................................................... 77
AES COMMANDS....................................................................................................................................... 77
AES PARAMETERS .................................................................................................................................... 77
AES TX/RXFIFO OPERATION .................................................................................................................. 78
SYSTEM CONSIDERATIONS AND GUIDELINES ......................................................................... 79
VOLTAGE REGULATORS ............................................................................................................................ 79
SRD REGULATIONS ................................................................................................................................... 79
FREQUENCY HOPPING AND MULTI-CHANNEL SYSTEMS ............................................................................ 79
CONTINUOUS TRANSMISSIONS .................................................................................................................. 79
BATTERY OPERATED SYSTEMS ................................................................................................................. 79
REGISTER DESCRIPTION ................................................................................................................. 80
SOLDERING INFORMATION .......................................................................................................... 114
DEVELOPMENT KIT ORDERING INFORMATION ................................................................... 114
REFERENCES ..................................................................................................................................... 114
GENERAL INFORMATION .............................................................................................................. 114
DOCUMENT HISTORY .............................................................................................................................. 114

SWRU346B

Page 4 of 114

CC120X
1

Overview

CC120X is a family of high performance low power RF transceivers designed for operation with a
companion MCU. The purpose of this user’s guide is to describe configurations and functionality
available for implementing a wireless system. CC120X automates all common RF related tasks, greatly
offloading the MCU. Below is a block diagram showing the different parts of the transceiver divided in
an RF related part and a part for digital support functionality.
CC120x
4 kbyte
ROM

MARC
Main Radio Control unit

LNA_N

ADC

256 byte
FIFO RAM
buffer

Configuration and
status registers

FREQ
SYNTH

0
90

RF and DSP frontend

Output power ramping and OOK / ASK modulation

14 dBm high
efficiency PA

PA out

Fully integrated fractional-N
frequency synthesizer

XOSC

BIAS

LFC1

LFC0

IF amp

SCLK (serial clock)

SO (GPIO0)
SI

(optional GPIO3/2/0

CS_N
GPIO1
GPIO2
GPIO3
(optional auto detected
external XOSC / TCXO)

XOSC
XOSC_Q2

90 dB dynamic
range ADC

High linearity
LNA
LNA_N

SCLK

SO (serial output)

XOSC_Q1

Data interface with
signal chain access

(optional bit clock)

Channel
filter

IF amp

EXT_XOSC

XOSC_Q1

LNA_P

XOSC_Q2

RBIAS

Packet handler
and FIFO control

Cordic

Battery sensor /
temp sensor

Interrupt and
IO handler

DIGITAL INTERFACE TO MCU

LNA

TXFIFO

ADC

RXFIFO

SI (serial input)

DEMODULATOR

System bus

LNA_P

CSn (chip select)

MCU

AES-128
accelerator

eWOR
Enhanced ultra low power
Wake On Radio timer

SPI
Serial configuration

Ultra low power
16 bit
RADIO CONTROL & POWER
MANAGEMENT
and data interface

PACKET HANDLER

Power on reset

Modulator

Ultra low power 40 kHz
auto-calibrated RC oscillator

MODULATOR

(optional 40 kHz
clock intput)

Highly flexible FSK / OOK
demodulator

90 dB dynamic
range ADC

(optional low jitter serial
data output for legacy
protocols)

AGC
Automatic Gain Control, 60dB VGA range
RSSI measurements and carrier sense detection

(optional GPIO for
antenna diversity)

Figure 1: CC120X Block Diagram

CC120X can be configured to achieve optimum performance for many different applications using the
SPI interface (see Section 3.1.1 for more details). The following key parameters can be programmed:
Power-down/power-up mode (SLEEP/IDLE)
Crystal oscillator power-up/power-down (IDLE/XOFF)
Receive/transmit mode (RX/TX)
Carrier frequency
Symbol rate
Modulation format
RX channel filter bandwidth
RF output power
Data buffering with separate 128-byte receive and transmit FIFOs
Packet radio hardware support
Data whitening
Enhanced Wake-On-Radio (eWOR)
Figure 1 shows a simplified state diagram. For detailed information on controlling the CC120X state
machine see Section 9.

SWRU346B

Page 5 of 114

CC120X
SLEEP
SPWD or wake-on-radio (WOR)

SIDLE

Lowest power mode. Most
register values are retained
(see Table 5 for details ).

Default state when the radio is not
receiving or transmitting.

CSn = 0

IDLE
SXOFF
SCAL

Used for calibrating frequency
synthesizer upfront (entering
Manual freq.
receive or transmit mode can
synth. calibration
then be done quicker).
Transitional state.

CSn = 0
SRX or STX or SFSTXON or wake-on-radio (WOR)

SFSTXON

Frequency synthesizer is on,
ready to start transmitting.
Transmission starts very
quickly after receiving the STX
command strobe.

Frequency
synthesizer startup,
optional calibration,
settling

Crystal
oscillator off

All register values are
retained.

Frequency synthesizer is turned on, can optionally be
calibrated, and then settles to the correct frequency.
Transitional state.

Frequency
synthesizer on
STX
SRX or wake-on-radio (WOR)
STX

TXOFF_MODE = 01

SFSTXON or RXOFF_MODE = 01
SRX

STX or RXOFF_MODE=10

Transmit mode

Receive mode

SRX or TXOFF_MODE = 11

TXOFF_MODE = 00

RXOFF_MODE = 00

Optional transitional state.
In FIFO-based modes,
transmission is turned off and
this state entered if the TX
FIFO becomes empty in the
middle of a packet.

TX FIFO
ERROR

Optional freq.
synth. calibration

SFTX

RX FIFO
ERROR

In FIFO-based modes,
reception is turned off and this
state entered if the RX FIFO
overflows.

SFRX

IDLE

Figure 2: Simplified State Diagram

Configuration Software

CC112X can be configured using the SmartRF™ Studio software [1]. SmartRF Studio is highly
recommended for obtaining optimum register settings, and for evaluating performance and
functionality.
After chip reset, all registers have default values and these might differ from the optimum register
setting. It is therefore necessary to configure/reconfigure the radio through the SPI interface after the
chip has been reset. SmartRF Studio provides a code export function making it easy to implement this
in firmware.

SWRU346B

Page 6 of 114

CC120X
3

Microcontroller Interface

3.1

Configuration

In a typical system, CC120X will interface to an MCU. This MCU must be able to communicate with the
CC120X over a 4-wire SPI interface to be able to:
Configure the CC120X
Program CC120X into different modes (RX, TX, SLEEP, IDLE, etc)
Read and write buffered data (RX FIFO and TX FIFO)
Read status information
3.1.1

4-wire Serial Configuration and Data Interface

CC120X is configured via a simple 4-wire SPI-compatible interface (SI, SO, SCLK, and CSn) where
CC120X is the slave. This interface is also used to read and write buffered data. All transfers on the SPI
interface are done most significant bit first.
All transactions on the SPI interface start with a header byte containing a R/W̄ bit, a burst access bit
(B), and a 6-bit address (A5 - A0). A status byte is sent on the SO pin each time a header byte is
transmitted on the SI pin (see Section 3.1.2 for more details on the chip status byte).
The CSn pin must be kept low during transfers on the SPI bus. The timing for the address and data
transfers on the SPI interface is shown in Figure 3 with reference to Table 1.
tsp

tch

tcl

tsd

thd

tns

SCLK
CSn
Write to Register
SI
SO

X
Hi Z

S0 S0

DW7

DW6

DW5

DW4

DW3

DW2

DW1

DW0

DR3

DR2

DR1

DR0

X
Hi Z

Read from Register
SI
SO

X
Hi Z

S0 S0

X
DR7

DR6

DR5

DR4

Hi Z

Figure 3: Configuration Registers Write and Read Operations
Parameter

Description

Min

Max

Units

fSCLK

SCLK frequency read/write access

MHz

Note: A 100 ns delay between consecutive data bytes must be added during burst write access to the configuration
registers

tsp
tch
tcl
trise
tfall
tsd
thd
tns

SCLK frequency read access extended memory
CSn low to positive edge on SCLK
Clock high
Clock low
Clock rise time
Clock fall time
Setup data before a positive edge on SCLK
Hold data after positive edge on SCLK
Negative edge on SCLK to CSn high.
CSn high time, time from CSn has been pulled high until it can be pulled low again

50
47.5
47.5
10
10
200
50

7.7
40
40
-

ns
ns
ns
ns
ns
ns
ns
ns
ns

Table 1: SPI Timing Requirements

SWRU346B

Page 7 of 114

CC120X
When CSn is pulled low, the MCU must wait until CC120X SO pin goes low before starting to transfer
the header byte. This indicates that the crystal is stable. Unless the chip was just reset or was in
SLEEP or XOFF state, or the XOSC configuration has been altered, the SO pin will always go low
immediately after pulling CSn low.
Registers with consecutive addresses can be accessed in an efficient way by setting the burst bit (B)
in the header byte. The address bits (A5 - A0) set the start address in an internal address counter. This
counter is incremented by one each new byte (every 8 clock pulses). The burst access is either a
read or write, and must be terminated by setting CSn high.
If a single register shall be accessed multiple times (e.g. CFM_RX_DATA_OUT/ CFM_TX_DATA_IN for
custom frequency modulation, see Section 5.2.4), the EXT_CTRL.BURST_ADDR_INCR_EN bit can be
set to 0. In this mode the address counter will not increment in burst mode, and it is possible to
read/write the same register repeatedly without address overhead.
Table 3 gives an overview of the different SPI access types possible.
3.1.2

Chip Status Byte

When the header byte, data byte, or command strobe is sent on the SPI interface, the chip status byte
is sent by the CC120X on the SO pin. The status byte contains key status signals, useful for the MCU.
The first bit, S7, is the CHIP_RDYn signal and this signal must go low before the first positive edge of
SCLK. The CHIP_RDYn signal indicates that the crystal is stable.
S6, S5, and S4 comprise the STATE value which reflects the state of the chip. In IDLE state the XOSC
and power to the digital core are on and all other modules are in power down. Unless otherwise
stated, registers should not be changed unless the chip is in this state.
Table 2 gives a status byte summary.
Bits
7

Name
CHIP_RDYn

6:4

STATE[2:0]

3:0

Description
Stays high until power and crystal have stabilized. Should always be low when using the SPI
interface.
Indicates the current main state machine mode
Value
State
MARC State
Description
000
IDLE
IDLE
IDLE state
001

010

011
100

FSTXON
CALIBRATE

101

SETTLING

110

RX FIFO
ERROR

111

TX FIFO
ERROR

RX
RX_END
TX
TX_END
FSTXON
BIAS_SETTLE_MC
REG_SETTLE_MC
MANCAL
STARTCAL
ENDCAL
BIAS_SETTLE
REG_SETTLE
BWBOOST
FS_LOCK
IFADCON
RXTX_SWITCH
TXRX_SWITCH
IFADCON_TXRX
RX_FIFO_ERR

TX_FIFO_ERR

Receive mode
Transmit mode
Fast TX ready
Frequency synthesizer calibration is running

PLL is settling

RX FIFO has over/underflowed. Read out
any useful data, then flush the FIFO with an
SFRX strobe
TX FIFO has over/underflowed. Flush the
FIFO with an SFTX strobe

Reserved

Table 2: Status Byte Summary

SWRU346B

Page 8 of 114

CC120X
3.2

SPI Access Types

Figure 4 shows the SPI memory map and the following sections are going to explain how the different
SPI access types (see Table 3) should be used. Table 4 shows the SPI address space.
0x00

Extended Address Space
Register Space
Configuration Registers
0x00

0x2E
0x2F

Extended Register Space
Configuration Registers
Status Registers
FIFO Pointers
AES Workspace (key and buffer)

Extended Address

0x30

0xFF
Command Strobes
0x00

0x3D
0x3E

Direct Memory Access

0x3F

FIFO Access (push/pop)

FIFO Buffers
FEC Workspace
128 Bytes Free Area
(AES Command Workspace)
0xFF

Figure 4: SPI Memory Map
Access type
Single Register Access
(register space)

Command/Address byte
Address: R/W̄ 0 A5 A4 A3 A2 A1 A0
(A5 - 0 < 0x2F)

Burst Register Access
(register space)

Address: R/W̄ 1 A5 A4 A3 A2 A1 A0
(A5 - 0 < 0x2F)

Single Register Access
(extended register space)

Command: R/W̄ 0 1 0 1 1 1 1
Address: A7 A6 A5 A4 A3 A2 A1 A0
(A7 - 0: See Table 5)

Description
The R/W̄ bit determines whether the operation is a read (1)
or a write (0) operation
The register accessed is determined by the address in A5 - 0
Exactly one data byte is expected after the address byte
The chip status byte is returned on the SO line both when
the address is sent on the SI line as well as when data are
written
The R/W̄ bit determines whether the operation is a read (1)
or a write (0) operation
The address in A5 - 0 determines the first register accessed,
after which an internal address counter is incremented for
each new data byte following the address byte
Consecutive bytes are expected after the address byte and
the burst access is terminated by setting CSn high
The chip status byte is returned on the SO line both when
the address is sent on the SI line as well as when data are
written
If the internal address counter reaches address 0x2E (last
byte in register space) the counter will not increment
anymore and the same address will be read/written until the
burst access is being terminated
This access mode starts with a specific command (0x2F)
The first byte following this command is interpreted as the
extended address
Exactly one data byte is expected after the extended
address byte
When the extended address is sent on the SI line, SO will
return all zeros. The chip status byte is returned on the SO
line when the command is transmitted as well as when data
are written to the extended address

The FEC workspace is used by the chip when FEC is enabled (PKT_CFG1.FEC_EN = 1) but can
be used freely otherwise
Part of the 128 bytes “Free Area” is used by the AES accelerator. Please see Section 10 for more
details

SWRU346B

Page 9 of 114

CC120X
Access type
Burst Register Access
(extended register space)

Command/Address byte
Command: R/W̄ 1 1 0 1 1 1 1
Address: A7 A6 A5 A4 A3 A2 A1 A0
(A7 - 0: See Table 5)

Command Strobe Access

Address: R/W̄ 0 A5 A4 A3 A2 A1 A0
(0x30 ≤ A5 - 0 ≤ 0x3D)

Standard FIFO Access

Address: R/W̄ B 1 1 1 1 1 1

Direct Access to FIFO
Buffers

Command: R/W̄ B 1 1 1 1 1 0
Address: A7 A6 A5 A4 A3 A2 A1 A0
SPI_DIRECT_ACCESS_CFG in
SERIAL_STATUS must be 0
A7 - 0 < 0x80: TX FIFO
0x80 ≤ A7 - 0 ≤ 0xFF: RX FIFO

Direct Access to FEC
Workspace

Direct Access to 128 Bytes
Free Area (AES Command
Workspace)

Command: R/W̄ B 1 1 1 1 1 0
Address: A7 A6 A5 A4 A3 A2 A1 A0
SPI_DIRECT_ACCESS_CFG in
SERIAL_STATUS must be 1
(A7 - 0 < 0x80)
Command: R/W̄ B 1 1 1 1 1 0
Address: A7 A6 A5 A4 A3 A2 A1 A0
SPI_DIRECT_ACCESS_CFG in
SERIAL_STATUS must be 1
0x80 ≤ A7 - 0 ≤ 0xFF

Description
This access mode starts with a specific command (0x2F)
The first byte following this command is interpreted as the
extended address
Consecutive bytes are expected after the extended address
byte and the burst access is terminated by setting CSn high
When the extended address is sent on the SI line, SO will
return all zeros. The chip status byte is returned on the SO
line when the command is transmitted as well as when data
are written to the extended address.
If the internal address counter reaches address 0xFF (last
byte in extended register space) the counter will wrap
around to 0x00
Registers not listed in Table 5 can be part of a burst access
Accessing one of the command strobe registers triggers an
event determined by the address in A5 - 0, e.g. resetting the
device, enabling the crystal oscillator, entering TX, etc. No
data byte is expected.
The chip status byte is returned on the SO line when a
command strobe is sent on the SI line
The R/W̄ bit determines whether the operation is a read (1)
operation from the RX FIFO or a write (0) operation to the
TX FIFO. If the burst bit B is 1, all bytes following the
address byte are treated as data bytes until CSn goes high.
If the burst bit B is 0, the FIFOs are accessed byte-wise as
a normal register.
This access mode starts with a specific command (0x3E)
which makes it possible to access the FIFOs directly
through memory operations without affecting the FIFO
pointers.
The first byte following this command is interpreted as the
address. The next byte is read/written to this address. If
burst is enabled, consecutive bytes will be read/written by
incrementing the address.2
FIFO pointers are available in extended register space for
debug purposes.
This access mode starts with a specific command (0x3E)
which makes it possible to access the FEC workspace.
The first byte following this command is interpreted as the
address. The next byte is read/written to this address. If
burst is enabled, consecutive bytes will be read/written by
incrementing the address.
This access mode starts with a specific command (0x3E)
which makes it possible to access 128 bytes of free
memory.
The first byte following this command is interpreted as the
address. The next byte is read/written to this address. If
burst is enabled, consecutive bytes will be read/written by
incrementing the address.

Table 3: SPI Access Types

Note that the first byte received in an empty RX FIFO will not be possible to read using direct FIFO
access but can be read from extended register space ( A7 – 0 = 0xDA). Please see Section 3.2.3 for more
details.

SWRU346B

Page 10 of 114

CC120X

SRES
SFSTXON
SXOFF
SCAL
SRX
STX
SIDLE
SAFC
SWOR
SPWD
SFRX
SFTX
SWORRST
SNOP
TX FIFO

Command Strobes

0x00
0x01
0x02
0x03
0x04
0x05
0x06
0x07
0x08
0x09
0x0A
0x0B
0x0C
0x0D
0x0E
0x0F
0x10
0x11
0x12
0x13
0x14
0x15
0x16
0x17
0x18
0x19
0x1A
0x1B
0x1C
0x1D
0x1E
0x1F
0x20
0x21
0x22
0x23
0x24
0x25
0x26
0x27
0x28
0x29
0x2A
0x2B
0x2C
0x2D
0x2E
0x2F
0x30
0x31
0x32
0x33
0x34
0x35
0x36
0x37
0x38
0x39
0x3A
0x3B
0x3C
0x3D
0x3E
0x3F

Read
Single Byte
Burst
+0x80
+0xC0
IOCFG3
IOCFG2
IOCFG1
IOCFG0
SYNC3
SYNC2
SYNC1
SYNC0
SYNC_CFG1
SYNC_CFG0
DEVIATION_M
MODCFG_DEV_E
DCFILT_CFG
PREAMBLE_CFG1
PREAMBLE_CFG0
IQIC
CHAN_BW
MDMCFG1
MDMCFG0
SYMBOL_RATE2
SYMBOL_RATE1
SYMBOL_RATE0
AGC_REF
AGC_CS_THR
AGC_GAIN_ADJUST
AGC_CFG3
AGC_CFG2
AGC_CFG1
AGC_CFG0
FIFO_CFG
DEV_ADDR
SETTLING_CFG
FS_CFG
WOR_CFG1
WOR_CFG0
WOR_EVENT0_MSB
WOR_EVENT0_LSB
RXDCM_TIME
PKT_CFG2
PKT_CFG1
PKT_CFG0
RFEND_CFG1
RFEND_CFG0
PA_CFG1
PA_CFG0
ASK_CFG
PKT_LEN
EXTENDED ADDRESS
SRES
SFSTXON
SXOFF
SCAL
SRX
STX
SIDLE
SAFC
SWOR
SPWD
SFRX
SFTX
SWORRST
SNOP
DIRECT MEMORY ACCESS
TX FIFO
RX FIFO
RX FIFO

R/W configuration registers, burst access possible

Write
Single Byte
Burst
+0x00
+0x40

Table 4: SPI Address Space

SWRU346B

Page 11 of 114

CC120X
3.2.1

The configuration registers on the CC120X are located on SPI addresses from 0x00 to 0x2E (register
space) with address extension command at address 0x2F to access the extended register space (see
Figure 4). All configuration registers can be both written to and read and this is controlled by the R/W̄
bit in the header byte. All configuration registers can also be accessed with the burst bit (B) set to
either 1 or 0. Note that all registers in register space (address 0x00 - 0x2E) have retention. In
extended register space, the status registers, FIFO pointers, and the AES workspace do not have
retention. Please see Table 5 for details.
Extended Register Space (0x00 - 0x2F)
0x00
IF_MIX_CFG
0x01
FREQOFF_CFG
0x02
TOC_CFG
0x03
MARC_SPARE
0x04
ECG_CFG
0x05
MDMCFG2
0x06
EXT_CTRL
0x07
RCCAL_FINE
0x08
RCCAL_COARSE
0x09
RCCAL_OFFSET
0x0A
FREQOFF1
0x0B
FREQOFF0
0x0C
FREQ2
0x0D
FREQ1
0x0E
FREQ0
0x0F
IF_ADC2
0x10
IF_ADC1
0x11
IF_ADC0
0x12
FS_DIG1
0x13
FS_DIG0
0x14
FS_CAL3
0x15
FS_CAL2
0x16
FS_CAL1
0x17
FS_CAL0
0x18
FS_CHP
0x19
FS_DIVTWO
0x1A
FS_DSM1
0x1B
FS_DSM0
0x1C
FS_DVC1
0x1D
FS_DVC0
0x1E
FS_LBI
0x1F
FS_PFD
0x20
FS_PRE
0x21
FS_REG_DIV_CML
0x22
FS_SPARE
0x23
FS_VCO4
0x24
FS_VCO3
0x25
FS_VCO2
0x26
FS_VCO1
0x27
FS_VCO0
0x28
GBIAS6
0x29
GBIAS5
0x2A
GBIAS4
0x2B
GBIAS3
0x2C
GBIAS2
0x2D
GBIAS1
0x2E
GBIAS0
0x2F
IFAMP

Retention
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes

SWRU346B

Extended Register Space (0x30 - 0x86)
0x30
LNA
0x31
RXMIX
0x32
XOSC5
0x33
XOSC4
0x34
XOSC3
0x35
XOSC2
0x36
XOSC1
0x37
XOSC0
0x38
ANALOG_SPARE
0x39
PA_CFG3
0x3A - 0x3E
Not Used
0x3F - 0x40
Reserved
0x41 - 0x63
Not Used
0x64
WOR_TIME1
0x65
WOR_TIME0
0x66
WOR_CAPTURE1
0x67
WOR_CAPTURE0
0x68
BIST
0x69
DCFILTOFFSET_I1
0x6A
DCFILTOFFSET_I0
0x6B
DCFILTOFFSET_Q1
0x6C
DCFILTOFFSET_Q0
0x6D
IQIE_I1
0x6E
IQIE_I0
0x6F
IQIE_Q1
0x70
IQIE_Q0
0x71
RSSI1
0x72
RSSI0
0x73
MARCSTATE
0x74
LQI_VAL
0x75
PQT_SYNC_ERR
0x76
DEM_STATUS
0x77
FREQOFF_EST1
0x78
FREQOFF_EST0
0x79
AGC_GAIN3
0x7A
AGC_GAIN2
0x7B
AGC_GAIN1
0x7C
AGC_GAIN0
0x7D
CFM_RX_DATA_OUT
0x7E
CFM_TX_DATA_IN
0x7F
ASK_SOFT_RX_DATA
0x80
RNDGEN
0x81
MAGN2
0x82
MAGN1
0x83
MAGN0
0x84
ANG1
0x85
ANG0
0x86
CHFILT_I2

Retention
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes

No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No

Page 12 of 114

CC120X
Extended Register Space (0x87 - 0x9D)
0x87
CHFILT_I1
0x88
CHFILT_I0
0x89
CHFILT_Q2
0x8A
CHFILT_Q1
0x8B
CHFILT_Q0
0x8C
GPIO_STATUS
0x8D
FSCAL_CTRL
0x8E
PHASE_ADJUST
0x8F
PARTNUMBER
0x90
PARTVERSION
0x91
SERIAL_STATUS
0x92
MODEM_STATUS1
0x93
MODEM_STATUS0
0x94
MARC_STATUS1
0x95
MARC_STATUS0
0x96
PA_IFAMP_TEST
0x97
FSRF_TEST
0x98
PRE_TEST
0x99
PRE_OVR
0x9A
ADC_TEST
0x9B
DVC_TEST
0x9C
ATEST
0x9D
ATEST_LVDS

Retention
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No

Extended Register Space (0x9E - 0xFF)
0x9E
ATEST_MODE
0x9F
XOSC_TEST1
0xA0
XOSC_TEST0
0xA1
AES
0xA2
MDM_TEST
0xA3 - 0xD1
Not Used
0xD2
RXFIRST
0xD3
TXFIRST
0xD4
RXLAST
0xD5
TXLAST
0xD6
NUM_TXBYTES
0xD7
NUM_RXBYTES
0xD8
FIFO_NUM_TXBYTES
0xD9
FIFO_NUM_RXBYTES
0xDA
RXFIFO_PRE_BUF
0xDB - 0xDF
Not Used
0xE0 - 0xEF
AES_KEY

Retention
No
No
No
No
No

0xE0 - 0xFF

AES Workspace

0xF0 – 0xFF

AES_BUFFER

No
No
No
No
No
No
No
No
No
No

Table 5: Extended Register Space Mapping
3.2.2

Command Strobes

Command Strobes may be viewed as single byte instructions to CC120X. By addressing a command
strobe register, internal sequences will be started. These commands are used to enable receive and
transmit mode, enter SLEEP mode, disable the crystal oscillator, etc. The command strobes are listed
in Table 6.The command strobe registers are accessed by transferring a single header byte (no data
is being transferred). That is, only the R/W̄ bit, the burst access bit (set to 0), and the six address bits
(in the range 0x30 through 0x3D) are written. When sending a strobe, the R/W̄ bit can be either one
or zero. The status byte is available on the SO pin when a command strobe is being sent.
Address
0x30
0x31

Strobe Name
SRES
SFSTXON

Description
Reset chip
Enable and calibrate frequency synthesizer (if SETTLING_CFG.FS_AUTOCAL = 1).
If in RX and PKT_CFG2.CCA_MODE ≠ 0: Go to a wait state where only the synthesizer is
running (for quick RX/TX turnaround).
Enter XOFF state when CSn is de-asserted
Calibrate frequency synthesizer and turn it off. SCAL can be strobed from IDLE mode without
setting manual calibration mode (SETTLING_CFG.FS_AUTOCAL = 0)

0x32
0x33

SXOFF
SCAL

0x34

SRX

Enable RX. Perform calibration first if coming from IDLE and SETTLING_CFG.FS_AUTOCAL =
1

0x35

STX

In IDLE state: Enable TX. Perform calibration first if SETTLING_CFG.FS_AUTOCAL = 1.
If in RX state and PKT_CFG2.CCA_MODE ≠ 0: Only go to TX if channel is clear

0x36
0x37
0x38

SIDLE
SAFC
SWOR

Exit RX/TX, turn off frequency synthesizer and exit eWOR mode if applicable
Automatic Frequency Compensation
Start automatic RX polling sequence (eWOR) as described in Section 9.6 if
WOR_CFG0.RC_PD = 0

0x39
0x3A

SPWD
SFRX

Enter SLEEP mode when CSn is de-asserted

0x3B

SFTX

0x3C
0x3D

SWORRST
SNOP

Flush the TX FIFO. Only issue SFTX in IDLE or TX_FIFO_ERR states
Reset the eWOR timer to the Event1 value
No operation. May be used to get access to the chip status byte

Flush the RX FIFO. Only issue SFRX in IDLE or RX_FIFO_ERR states

Table 6: Command Strobes

SWRU346B

Page 13 of 114

CC120X
A command strobe may be followed by any other SPI access without pulling CSn high, and the
command strobes are executed immediately. This applies for all command strobes except SRES,
SPWD, SWOR, and the SXOFF strobe.
When a SRES strobe is issued the CSn pin must be kept low and wait for SO to go low again before
the next header byte can be issued, as shown in Figure 5.
CSn

HeaderSRES

HeaderAddr

Data

Figure 5: SRES Command Strobe
The SPWD, SWOR, and the SXOFF command strobes are not executed before the CSn goes high.
3.2.3

Direct FIFO Access

The complete RX and TX FIFOs, with associated pointers, are mapped in the register space for FIFO
manipulation and SW-debug purposes. The FIFOs are mapped as shown in Table 7 (the address
must be preceded by the command 0x3E) while the FIFO pointers are located in extended register
space (address 0xD2 - 0xD5, see Table 5).
Direct FIFO Access Mapping
0x00 - 0x7F
TXFIFO
0x80 - 0xFF
RXFIFO

Retention
No
No

Table 7: Direct FIFO Access Mapping
Both FIFO data and pointers are readable and writeable to enable e.g. re-transmissions, partial flush,
partial readouts, changing only the sequence number before re-transmission etc. Figure 6 shows how
the TX FIFO pointer changes as the FIFO is written and as data are sent on the air (assume variable
packet length mode PKT_CFG0.LENGTH_CONFIG = 1.

SWRU346B

Page 14 of 114

CC120X
NUM_TXBYTES = 0x09
1

TXFIRST
STX:

126 127

TXLAST
1

transmitted on the air
NUM_TXBYTES = 0x07

TXFIRST
STX:

126 127

TXLAST
D2

transmitted on the air
NUM_TXBYTES = 0x04

TXFIRST
STX:

126 127

TXLAST

transmitted on the air
NUM_TXBYTES = 0x00

126 127

TXLAST
TXFIRST

Figure 6: FIFO Pointers (TX FIFO)
To transmit packet number 3 over again one can simply write 0x05 to the TXFIRST register and then
strobe STX again.
In RX mode, when the RX FIFO is empty (i.e. RXFIRST = RXLAST) the first byte received will not be
3
available to be read from the RXFIFO using direct FIFO access . Please see Figure 7 (it is assumed
that the receiver uses variable packet length mode (PKT_CFG0.LENGTH_CFG = 01) and that
append status is disabled (PKT_CFG1.APPEND_STATUS = 0) for this example).

This byte can instead be read from extended register space (A7 – 0 = 0xDA).

SWRU346B

Page 15 of 114

CC120X
NUM_RXBYTES = 0x00
x

126 127

RXFIRST
RXLAST
3

transmitted on the air and received by
the radio
NUM_RXBYTES = 0x04

RXFIRST
3

126 127

RXLAST
D0

transmitted on the air and received by
the radio
NUM_RXBYTES = 0x08

RXFIRST

126 127

RXLAST

Figure 7: FIFO Pointers (RX FIFO) (1)
If 8 bytes (NUM_RXBYTES = 0x08) are read from the RXFIFO using standard FIFO access (see
Section 3.2.4) the following will be read: 3, D0, D1, D2, 3, D0, D1, D2.
If the RX FIFO had been read (using standard FIFO access) in between the two packets, the RX
FIFO pointers would end up with the values shown in Figure 8.

NUM_RXBYTES = 0x04
D0

RXFIRST

126 127

RXLAST

Figure 8: FIFO Pointers (RX FIFO) (2)
3.2.4

Standard FIFO Access

Using the standard FIFO push/pop interface the 128-byte TX FIFO and the 128-byte RX FIFO are
accessed through the 0x3F address. When the R/W̄ bit is zero the TX FIFO is accessed, and the RX
FIFO is accessed when the R/W̄ bit is one. Using this type of access, the TX FIFO is write-only, while
the RX FIFO is read-only. The burst bit is used to determine if the FIFO access is a single byte access
or a burst access. The single byte access method expects a header byte with the burst bit set to zero
and one data byte. After the data byte, a new header byte is expected; hence CSn can remain low.
The burst access method expects one header byte and then consecutive data bytes until terminating
the access by setting CSn high.

SWRU346B

Page 16 of 114

CC120X
If the radio tries to write to the RX FIFO after it is full or if the RX FIFO is tried read when it is empty,
the RXFIFO_OVERFLOW and RXFIFO_UNDERFLOW signals will be asserted and the radio will enter the
RX_FIFO_ERR state. Likewise, if the TX FIFO is tried written when it is full or if the TX FIFO runs
empty in the middle of a packet, the TXFIFO_OVERFLOW and TXFIFO_UNDERFLOW signals will be
asserted and the radio will enter the TX_FIFO_ERR state.
The TX FIFO may be flushed by issuing a SFTX command strobe. Similarly, a SFRX command strobe
will flush the RX FIFO. A SFTX or SFRX command strobe can only be issued in the IDLE,
TX_FIFO_ERR, or RX_FIFO_ERR states. Both FIFOs are flushed when going to the SLEEP state.
3.3

Optional PIN CTRL Radio Control Feature

The CC120X has an optional way of controlling the radio by reusing SI, SCLK, and CSn from the SPI
interface. This feature allows for a simple three-pin control of the major states of the radio: SLEEP,
IDLE, RX, and TX. This optional functionality is enabled with the EXT_CTRL.PIN_CTRL_EN
configuration bit.
State changes are commanded as follows:
When CSn is high, the SI and SCLK are set to the desired state according to Table 8.
When CSn goes low, the state of SI and SCLK is latched and a command strobe is generated
internally according to the pin configuration.
If the device is in the TX state and the TX command is issued, it will be ignored. For RX state, an RX
command will restart RX. When CSn is low the SI and SCLK have normal SPI functionality.
All pin control command strobes are executed immediately, except the SPWD strobe. The SPWD strobe
is delayed until CSn goes high.
Pin control is useful to get precise timing on RX/TX strobes.
CSn
1

SCLK
X
0

SI
X
0

Function
Chip unaffected by SCLK/SI

Generates STX strobe

Generates SIDLE strobe

SPI
mode

Generates SRX strobe
SPI mode (wakes up into
IDLE if in SLEEP/XOFF)

Generates SPWD strobe

Table 8: Optional Pin Control Coding
3.4

General Purpose Input/Output Control Pins

The four digital I/O pins GPIO0, GPIO1, GPIO2 and GPIO3 are general control pins configured with
IOCFGx.GPIOx_CFG (where x is 0, 1, 2, or 3). Table 10 shows the different signals that can be
monitored on the GPIO pins. The signal name field in the table should be interpreted as follows:
One signal name: The signal can be routed out to any of the four GPIO pins for full flexibility
Four signal names: The signal can only be routed out on the GPIO designated in the table.
GPIO1 is shared with the SO pin in the SPI interface. The default setting for GPIO1/SO is HIGHZ (tristate) output, which is useful when the SPI interface is shared with other devices. By selecting any
other of the programming options, the GPIO1/SO pin will become a generic pin when CSn is high
and function as SO when CSn is low.
When the IOCFGx.GPIOx_CFG setting is less than 0x30 and IOCFGx.GPIOx_INV is 0 (1) the
GPIO0 and GPIO2 pin will be hardwired to 0 (1), and GPIO1 and GPIO3 will be hardwired to 1 (0) in
the SLEEP state. These signals will be hardwired until the CHIP_RDYn signal goes low. If the
IOCFGx.GPIOx_CFG setting is 0x30 or higher, the GPIO pins will work as programmed also in
SLEEP state.
The GPIOs can also be used as inputs by setting IOCFGx.GPIOx_CFG = HIGHZ (48). Table 9
shows which signals can be input to the CC112X.

SWRU346B

Page 17 of 114

CC120X
GPIO Pin
0

Signal Name
SERIAL_TX

1
2

Reserved
SYNC_DETECT

EXT_40K_CLOCK

Signal Description
Serial data (TX mode). Used for both synchronous and transparent
mode.
Synchronous serial mode: Data is captured on the rising edge of the
serial clock
In blind mode (see Section 5.1.2.2) sync detection must be done by the
MCU. When sync is found, the MCU should assert an output connected
to this pin (GPIO2) to make the receiver switch modem parameters from
sync search settings to packet receive settings similar as what is done in
FIFO mode/normal mode (see for instance
AGC_CFG3.AGC_SYNC_BEHAVIOUR). SYNC_CFG0.EXT_SYNC_DETECT
must be 1
External 40 kHz clock signal

Table 9: GPIO Input Pin Mapping
When changing IOCFGx.GPIOx_CFG or IOCFGx.GPIOx_INV the output can be unstable and this
should be handled by the MCU by for instance disable interrupts on GPIO pins until re-configuration is
done.
3.4.1

MCU Input/Interrupt

There are two main methods that can be used to generate an input/interrupt to the MCU
1. GPIO Signals
2. MCU WAKEUP
3.4.1.1

GPIO Signals

See Table 10 for the different signals that can be output from the CC120X. Note that all signals
described as a pulse are two XOSC periods long.
GPIOx_CFG
0

Signal Name
RXFIFO_THR

Description
Associated to the RX FIFO. Asserted when the RX FIFO is filled above
FIFO_CFG.FIFO_THR. De-asserted when the RX FIFO is drained below
(or is equal) to the same threshold. This signal is also available in the
MODEM_STATUS1 register
Associated to the RX FIFO. Asserted when the RX FIFO is filled above
FIFO_CFG.FIFO_THR or the end of packet is reached. De-asserted
when the RX FIFO is empty
Associated to the TX FIFO. Asserted when the TX FIFO is filled above
(or is equal to) (127 −FIFO_CFG.FIFO_THR). De-asserted when the TX
FIFO is drained below the same threshold. This signal is also available in
the MODEM_STATUS0 register

RXFIFO_THR_PKT

TXFIFO_THR

TXFIFO_THR_PKT

Associated to the TX FIFO. Asserted when the TX FIFO is full. Deasserted when the TX FIFO is drained below
(127 − FIFO_CFG.FIFO_THR)

RXFIFO_OVERFLOW

TXFIFO_UNDERFLOW

PKT_SYNC_RXTX

CRC_OK

SERIAL_CLK

SERIAL_RX

Asserted when the RX FIFO has overflowed. De-asserted when the RX
FIFO is flushed (see Section 3.2.4). This signal is also available in the
MODEM_STATUS1 register
Asserted when the TX FIFO has underflowed. De-asserted when the TX
FIFO is flushed (see Section 3.2.4). This signal is also available in the
MODEM_STATUS0 register
RX: Asserted when sync word has been received and de-asserted at the
end of the packet. Will de-assert when the optional address and/or
length check fails or the RX FIFO overflows/underflows.
TX: Asserted when sync word has been sent, and de-asserted at the end
of the packet. Will de-assert if the TX FIFO underflows/overflows
Asserted simultaneously as PKT_CRC_OK. De-asserted when the first
byte is read from the RX FIFO
Serial clock (RX and TX mode). Synchronous to the data in synchronous
serial mode. Data is set up on the falling edge in RX and is captured on
the rising edge of the serial clock in TX
Serial data (RX mode). Used for both synchronous and transparent
mode.
Synchronous serial mode: Data is set up on the falling edge.
Transparent mode: No timing recovery (outputs just the hard limited
baseband signal)

SWRU346B

Page 18 of 114

CC120X
10
11

PQT_REACHED

PQT_VALID

13
14

RSSI_VALID
3
2
1

RSSI_UPDATE
RSSI_UPDATE
AGC_HOLD

AGC_UPDATE

3
2

CCA_STATUS
TXONCCA_DONE

1
0

CCA_STATUS
TXONCCA_FAILED

CARRIER_SENSE_VALID

CARRIER_SENSE

Reserved (used for test)
Preamble Quality Reached. Asserted when the quality of the preamble is
above the programmed PQT value (see Section 6.8). This signal is also
available in the MODEM_STATUS1 register
Preamble quality valid. Asserted when the PQT logic has received a
sufficient number of symbols (see Section 6.8). This signal is also
available in the MODEM_STATUS1 register
RSSI calculation is valid
RSSI Signals
A pulse occurring each time the RSSI value is updated (see Figure 16)
A pulse occurring each time the RSSI value is updated (see Figure 16)
AGC waits for gain settling (see Figure 16)
A pulse occurring each time the front end gain has been adjusted
(see Figure 16)
Clear channel assessment
Current CCA status
A pulse occurring when a decision has been made as to whether the
channel is busy or not. This signal must be used as an interrupt to the
MCU. When this signal is asserted/de-asserted, TXONCCA_FAILED can
be checked
Current CCA status
TX on CCA failed. This signal is also available in the MARC_STATUS0
register
CARRIER_SENSE is valid (see Figure 16)
Carrier sense. High if RSSI level is above threshold (see Section 6.9.1)
(see Figure 16)
DSSS signals for DSSS repeat mode (RX).
MODCFG_DEV_E.MODEM_MODE = 1

3 DSSS_CLK
2 DSSS_DATA0
1 DSSS_CLK
0 DSSS_DATA1
PKT_CRC_OK

DSSS clock (see Section 5.2.6 for more details)
DSSS data0 (see Section 5.2.6 for more details)
DSSS clock (see Section 5.2.6 for more details)
DSSS data1 (see Section 5.2.6 for more details)
Asserted in RX when PKT_CFG1.CRC_CFG = 1 or 10b and a good
packet is received. This signal is always on if the radio is in TX or if the
radio is in RX and PKT_CFG1.CRC_CFG = 0. The signal is de-asserted
when RX mode is entered and PKT_CFG1.CRC_CFG ≠ 0. This signal
is also available in the LQI_VAL register

MCU_WAKEUP

SYNC_LOW0_HIGH1

23
24
25

3
2
1
0 AES_COMMAND_ACTIVE
LNA_PA_REG_PD
LNA_PD
PA_PD

MCU wake up signal. Read MARC_STATUS1.MARC_STATUS_OUT to find
the cause of the wake up event (see Section 3.4.1.2 for more details).
This signal is also available in the MARC_STATUS0 register. The signal is
a pulse
DualSync detect. Only valid when SYNC_CFG1.SYNC_MODE = 111b.
When SYNC_EVENT is asserted this bit can be checked to see which
sync word is found. This signal is also available in the DEM_STATUS
register
Reserved (used for test)
Reserved (used for test)
Reserved (used for test)
Indicates that an AES command is being executed
Common regulator control for PA and LNA. Indicates RF operation
Control external LNA4

RX0TX1_CFG

27
28
29

IMAGE_FOUND
CLKEN_CFM

Control external PA4
Indicates whether RF operation is in RX or TX (this signal is 0 in IDLE
state)
Reserved (used for test)
Image detected by image rejection calibration algorithm
Data clock for demodulator soft data (see Section 5.2.4 for more details)

This signal is active low. To control an external LNA, PA, or RX/TX switch in applications where the
SLEEP state is used it is therefore recommended to map this signal to GDO3 as this signal will be
hardwired to 1(0) in the SLEEP state.

SWRU346B

Page 19 of 114

CC120X
30
31 - 32
33

CFM_TX_DATA_CLK

AES_RUN

2
1

AES_RUN
RSSI_STEP_EVENT

Same as 3
RSSI step detected. This signal is asserted if there is an RSSI step of 3
or 6 dB during sync search or if there is an RSSI step of 10 or 16 dB
during packet reception. The RSSI step is configured through
AGC_CFG1.RSSI_STEP_THR). The signal is a pulse

0
3
2
1

RSSI_STEP_EVENT

Same as 1
Reserved (used for test)
Reserved (used for test)
Out of lock status signal. Indicates out of lock when the signal goes low.
This signal is also available in the FSCAL_CTR register

RSSI_STEP_FOUND

LOCK

0
LOCK
ANTENNA_SELECT

MARC_2PIN_STATUS[1]

38
39

MARC_2PIN_STATUS[0]
3
2 TXFIFO_OVERFLOW

1
0

RXFIFO_UNDERFLOW

3
2
1
0
3

MAGN_VALID
CHFILT_VALID
RCC_CAL_VALID
CHFILT_STARTUP_VALID
COLLISION_FOUND

2 SYNC_EVENT
1 COLLISION_FOUND
0 COLLISION_EVENT
PA_RAMP_UP
3 CRC_FAILED
2 LENGTH_FAILED
1 ADDR_FAILED
0 UART_FRAMING_ERROR
AGC_STABLE_GAIN

AGC_UPDATE

42
43

Data clock for modulator soft data (see Section 5.2.4 for more details)
Reserved (used for test)
RSSI step found during packet reception (after the assertion of
SYNC_EVENT). The RSSI step is either 10 or 16 dB (configured through
AGC_CFG1.RSSI_STEP_THR). This signal is also available in the
DEM_STATUS register
AES enable. This signal is asserted as long as the AES module is
enabled given that AES.AES_ABORT = 0. This signal is also available
in the AES register

Same a 1
Antenna diversity control. Can be used to control external antenna
switch. If differential signal is needed, two GPIOs can be used with one
of them having IOCFGx.GPIOx_INV set to 1
Partial MARC state status. These signals are also available in the
MARCSTATE register
MARC_2PIN_STATUS[1]
MARC_2PIN_STATUS[0]
State
0
0
SETTLING
0
1
TX
1
0
IDLE
1
1
RX
See MARC_2PIN_STATUS[1]
Reserved (used for test)
Asserted when the TX FIFO has overflowed. De-asserted when the TX
FIFO is flushed (see Section 3.2.4). This signal is also available in the
MODEM_STATUS0 register
Reserved (used for test)
Asserted when the RX FIFO has underflowed. De-asserted when the RX
FIFO is flushed (see Section 3.2.4). This signal is also available in the
MODEM_STATUS1 register
New CORDIC magnitude sample
New channel filter sample
RCOSC calibration has been performed at least once
Channel filter has settled
Asserted if a new preamble is found and the RSSI has increased 10 or
16 dB during packet reception.
( MDMCFG1.COLLISION_DETECT_EN = 1)
This signal is also available in the DEM_STATUS register
Sync word found (pulse)
Same as 3
Preamble found during receive with an RSSI step of 10 or 16 dB (pulse)
Asserted when ramping is started (for compliance testing)
Packet CRC error
Packet length error
Packet address error
Packet UART framing error
AGC has settled to a gain. The AGC gain is reported stable whenever
the current gain setting is equal to the previous gain setting. This
condition is evaluated each time a new internal RSSI estimate is
computed (see Figure 16)
A pulse occurring each time the front end gain has been adjusted
(see Figure 16)

SWRU346B

Page 20 of 114

CC120X
46
3
2
1
0

ADC_CLOCK
ADC_Q_DATA_SAMPLE
ADC_CLOCK
ADC_I_DATA_SAMPLE

47
48
49

HIGHZ
EXT_CLOCK

50
51

CHIP_RDYn
HW0

52 - 53
54
55
56
57
58
59
60

CLOCK_40K
WOR_EVENT0
WOR_EVENT1
WOR_EVENT2
XOSC_STABLE
EXT_OSC_EN

61 - 63

ADC data (test purposes only)
ADC clock
ADC sample (Q data)
ADC clock
ADC sample (I data)
Reserved (used for test)
High impedance (tri-state)
External clock (divided crystal clock). The division factor is controlled
through the ECG_CFG.EXT_CLOCK_FREQ register field
Chip ready (XOSC is stable)
HW to 0 (HW to 1 achieved with IOCFGx.GPIOx_INV = 1)
(Reserved (used for test)
40 kHz clock output from internal RC oscillator
WOR EVENT0
WOR EVENT1
WOR EVENT2
Reserved (used for test)
XOSC is stable (has finished settling)
External oscillator enable (used to control e.g. a TCXO). Note that this
signal is only asserted is a TCXO is present
Reserved (used for test)

Table 10: GPIO Output Pin Mapping
3.4.1.2

MCU Wake-Up

The main purpose of the MCU wake-up feature is to wake up the MCU from power down mode at the
right time, i.e., when there is a need of intervention from the MCU side.
To use the MCU wake-up feature one of the GPIO pins should be configured to output the
MCU_WAKEUP signal (IOCFGx.GPIOx_CFG = MCU_WAKEUP (20)). Every time this signal is asserted,
the MCU should read MARC_STATUS1.MARC_STATUS_OUT to find the cause of the wake up event
and take appropriate action.
Table 11 shows all the different cases that can initiate a MCU wake-up (assertion of MCU_WAKEUP).
Please note that MCU_WAKEUP will only be asserted when the radio enters IDLE state.

SWRU346B

Page 21 of 114

CC120X
MARC_STATUS_OUT
00000000
00000001
00000010
00000011
00000100

00000101

00000110

00000111
00001000
00001001
00001010
00001011

01000000
10000000

Description
No failure
RX timeout occurred. Only valid in RX mode and when not using eWOR
RX termination based on CS or PQT. Only valid in RX mode and when not using eWOR
eWOR sync lost (16 slots with no successful reception). Only valid in Feedback eWOR mode
(WOR_CFG1.WOR_MODE = 0)
Packet discarded due to maximum length filtering. Only valid in RX mode and when
RFEND_CFG0.TERM_ON_BAD_PKT is enabled.
Note: In eWOR Normal & Feedback modes the wake up pulse will not be asserted and the CC120X
will go to SLEEP until the next time slot
Packet discarded due to address filtering. Only valid in RX mode and when
RFEND_CFG0.TERM_ON_BAD_PKT is enabled.
Note: In eWOR Normal & Feedback modes the wake up pulse will not be asserted and the CC120X
will go to SLEEP until the next time slot
Packet discarded due to CRC filtering. Only valid in RX mode and when
RFEND_CFG0.TERM_ON_BAD_PKT is enabled.
Note: In eWOR Normal & Feedback modes the wake up pulse will not be asserted and the CC120X
will go to SLEEP until the next time slot
TX FIFO overflow error occurred (the MCU should flush the TX FIFO)
TX FIFO underflow error occurred (the MCU should flush the TX FIFO)
RX FIFO overflow error occurred (the MCU should flush the RX FIFO)
RX FIFO underflow error occurred (the MCU should flush the RX FIFO)
TX ON CCA failed. A TX strobe was ignored due to a busy channel. In parallel the TXONCCA_DONE
signal is asserted together with the TXONCCA_FAILED signal. These signals can be output on GDO2
and GDO0 respectively by setting IOCFG2/0.GPIO2/0_CFG = 15. The TXONCCA_FAILED signal
is also available in the MARC_STATUS0 register together with TXONCCA_DONE
TX finished successfully (the CC120X is ready for the next operation)
RX finished successfully (a packet is in the RX FIFO ready to be read)

Table 11: MARC_STATUS_OUT
By setting RFEND_CFG0.CAL_END_WAKE_UP_EN = 1, the MCU will be given additional wake up
pulses at the end of calibration (MARC_STATUS_OUT will be 0).

On-Chip Temperature Sensor

The CC120X has a temperature sensor that can be activated by using the register settings shown in
Table 12. The temperature sensor is based on a PTAT current from a band-gap cell fed to a resistor
to generate a PTAT voltage.Please see DN403 [4] for more details.
Register
IOCFG1
ATEST
ATEST_MODE
GBIAS1

Value
0x80
0x2A
0x0C
0x07

Table 12: Register Settings for Activating the Temp Sensor

SWRU346B

Page 22 of 114

CC120X
5

Common Receive and Transmit Configurations

5.1

Data Communication Modes

The CC120X supports different ways of setting up data communication, each with a defined area of
use. The following sections contain a description of the high level functionality of these different
modes of operation.
5.1.1

FIFO Mode/Normal Mode

FIFO mode is the preferred mode of operation. In this mode data is read from the RX FIFO and
written to the TX FIFO, making the data transfer to/from the MCU less time critical compared to what
is the case in the other modes. Using the FIFOs to buffer data allows the MCU to be in sleep mode
during RX/TX, reducing system power consumption.
In FIFO mode, sync and preamble insertion/detection are done automatically, and several other
optional packet handling features are supported in this mode. FIFO mode/Normal mode is enabled by
setting PKT_CFG2.PKT_FORMAT = 0.
5.1.2

Synchronous Serial Mode

In synchronous serial mode, data is clocked in and out of the CC112X by a clock provided by the
device. More details on this mode are found in Section 8.9.1. Synchronous serial mode is enabled by
setting PKT_CFG2.PKT_FORMAT = 1.
5.1.2.1

Sync Insertion/Detection Enabled

After the sync word is received/transmitted (SYNC_CFG1.SYNC_MODE ≠ 0), data is clocked in/out on
a GPIO pin with the associated clock on another GPIO pin. The serial clock is not output from the
device before the sync word is sent/received, hence the MCU can be in sleep mode until sync is
detected in RX mode.
Synchronous serial mode makes use of the WaveMatch detector, which means the performance will
be similar to the performance in FIFO mode.
5.1.2.2

Sync Insertion/Detection Disabled (Blind Mode)

Blind mode is synchronous serial mode with SYNC_CFG1.SYNC_MODE = 0. In this mode, the CC120X
will demodulate data/noise and it is the MCU that needs to monitor the data stream to find the framing
information. The serial clock will run continuously when the radio is in active mode.
If framing information is present in the signal, it is strongly advised to use either FIFO mode or
synchronous serial mode with sync detection enabled to make use of the strong WaveMatch detector
in CC120X (see Section 6.6).
Blind mode can be used in applications with no framing information, e.g. streaming data applications.
5.1.3

Transparent Serial Mode

In transparent serial mode (PKT_CFG2.PKT_FORMAT = 11b) the CC120X is configured to resemble a
legacy analog RF front end device. In this mode data is only filtered through the channel filter and the
hard limited baseband signal is output directly on a GPIO pin. No symbol rate recovery or bit timing is
performed by the radio.
Transparent mode can be used for applications that have packet formats incompatible with the built-in
demodulator. Examples are pulse width modulation and pulse position modulation. When using
transparent mode, the demodulation must be performed by the MCU.
More details on this mode are found in Section 8.9.2.

SWRU346B

Page 23 of 114

CC120X
5.2

Modulation Formats

CC120X supports amplitude and frequency shift modulation formats. The desired modulation format is
set in the MODCFG_DEV_E.MOD_FORMAT register.
Optionally, the data stream can be Manchester encoded by the modulator and decoded by the
demodulator. This option is enabled by setting MDMCFG1.MANCHESTER_EN = 1. Note that
Manchester encoding/decoding is only performed on the payload (including optional length and
address field) and the CRC and that all packet handling features are still available. In applications
where preamble and sync word also need to be Manchester encoded, this can be achieved by
selecting PREAMBLE_CFG1.PREAMBLE_WORD = 10b or 11b and manually encoding a two byte long
sync word and write it to SYNC3/2/1/0.
5.2.1

Frequency Shift Keying

CC120X supports both 2-FSK and 4-FSK modulation. Both can optionally be shaped by a Gaussian
filter with BT = 0.5, producing a GFSK modulated signal. This spectrum-shaping feature improves
adjacent channel power (ACP) and occupied bandwidth. When selecting 4-(G)FSK, the preamble and
sync word is sent using 2-(G)FSK (see Figure 9).
1/Symbol Rate

1/Symbol Rate

+1
+1/3
-1/3
-1

Preamble
0xAA

00 01 01 11 10 00 11 01

Sync
0xD3

Data
0x17 0x8D

Figure 9: Data Sent Over the Air (MDMCFG2.SYMBOL_MAP_CFG = 0)
In ‘true’ 2-FSK systems with abrupt frequency shifting, the spectrum is inherently broad. By making
the frequency shift ‘softer’, the spectrum can be made significantly narrower. Thus, higher symbol
rates can be transmitted in the same bandwidth using GFSK.
When 2-(G)FSK/4-(G)FSK modulation is used, the DEVIATION_M and MODCFG_DEV_E.DEV_E
register specifies the expected frequency deviation of incoming signals in RX and should be the same
as the TX deviation for demodulation to be performed reliably and robustly.
The frequency deviation is programmed with the DEV_M and DEV_E values in the DEVIATION_M and
MODCFG_DEV_E.DEV_E register. The value has an exponent/mantissa form, and the resultant
deviation is given by Equation 1 and Equation 2.

f dev

f xosc
(256 DEV _ M ) 2 DEV _ E [Hz]
222
Equation 1: fdev (DEVIATION_E > 0)

f dev

f xosc
DEV _ M [Hz]
221

Equation 2: fdev (DEVIATION_E = 0)

SWRU346B

Page 24 of 114

CC120X
The symbol encoding can be configured through the MDMCFG2.SYMBOL_MAP_CFG register field as
5
shown in Table 13 (SYMBOL_MAP_CFG = 0 by default).
Format

2-(G)FSK
OOK/ASK
4-(G)FSK

Symbol

‘0’
‘1’
‘00’
‘01’
‘10’
‘11’

Coding
SYMBOL_MAP_CFG
= 00b

SYMBOL_MAP_CFG
= 01b

SYMBOL_MAP_CFG
= 10b

SYMBOL_MAP_CFG =
11b

−Deviation [AMin]
+Deviation [AMax]
−Deviation /3
−Deviation
+Deviation /3
+Deviation

+Deviation [AMax]
−Deviation [AMin]
−Deviation
−Deviation /3
+Deviation
+Deviation /3

+Deviation[AMax]
−Deviation [AMin]
+Deviation /3
+Deviation
−Deviation /3
−Deviation

+Deviation [AMax]
−Deviation [AMin]
+Deviation
+Deviation /3
−Deviation
−Deviation /3

Table 13: Symbol Encoding for 2-(G)FSK and 4-(G)FSK Modulation
5.2.2

Amplitude Modulation (ASK) and on-off keying (OOK)

CC120X supports two different forms of amplitude modulation: On-Off Keying (OOK) and Amplitude
Shift Keying (ASK).
OOK modulation simply turns the PA on or off to modulate ones and zeros respectively.
When using OOK/ASK bit shaping can be enabled and the CC120X allows programming of both the
shape length and of the modulation depth (the difference between 1 and 0). Pulse shaping produces
a more bandwidth constrained output spectrum (see Figure 10).
The shape length is configured through PA_CFG0.RAMP_SHAPE and the modulation depth is
configured through ASK_CFG.ASK_DEPTH.

Figure 10: OOK with Shaping

AMin = Minimum Amplitude and AMax = Maximum Amplitude when OOK/ASK is used

SWRU346B

Page 25 of 114

CC120X
5.2.3

Minimum Shift Keying
6

When using MSK , the complete transmission (preamble, sync word, and payload) will be MSK
modulated.
MSK modulation is configured by MODCFG_DEV_E.MOD_FORMAT set to 2-(G)FSK modulation and
frequency deviation set to ¼ of symbol rate. Then phase shifts are performed with a constant
transition time. Table 14 shows what the frequency deviation should be programmed to for different
symbol rates to achieve a modulation index ~0.5.
Symbol Rate [ksps]
1.0
1.2
2.4
4.8
9.6
19.6
38.4
50
76.8
100
125
250
500

Frequency Deviation [kHz]
0.25
0.3
0.6
1.2
2.4
4.8
9.6
12.5
19.2
25.0
31.25
62.5
125

Actual Modulation Index
0.4940
0.5083
0.5083
0.5004
0.5006
0.5001
0.5007
0.5005
0.4997
0.5005
0.5005
0.5005
0.5005

Table 14: MSK Parameters
5.2.4

Custom Frequency Modulation(CFM)/Analog FM

CC120X supports a simple scheme to do custom frequency modulation/analog FM (e.g. communication
with analog legacy voice devices, N-FSK systems). This feature utilizes the high resolution PLL and
lets the user in a simple way directly control/read the instantaneous frequency without SPI overhead.
Custom frequency modulation is enabled by setting MDMCFG2.CFM_DATA_EN = 1.
One register (CFM_TX_DATA_IN) is used to set the carrier frequency offset and another register
(CFM_RX_DATA_OUT) is used to read the instantaneous frequency offset. The two registers have the
same format (two’s complement) to simplify SW control in both TX and RX. Accessing these registers
should be done using burst mode combined with setting EXT_CTRL.BURST_ADDR_INCR_EN = 0 to
continuously access the same address without any SPI address overhead.
The signal CFM_TX_DATA_CLK can be output on a GPIO by setting IOCFGx.GPIOx_CFG = 30. This
signal will be asserted every time the CFM_TX_DATA_IN register should be written and should be
used as an interrupt to the MCU to synchronize the SPI data to the internal modulation rate. The
signal runs at 16x the programmed symbol rate.
The signal CLKEN_CFM should be output on a GPIO (IOCFGx.GPIOx_CFG = 29) and used as a
trigger to read the CFM_RX_DATA_OUT samples. This signal runs at the same rate as the
programmed symbol rate.
Note that in TX mode, 3 dummy symbols should be written to the CFM_TX_DATA_IN register before
strobing SIDLE in order for all symbols to be sent on the air before TX mode is ended.

Identical to offset QPSK with half-sine shaping (data coding may differ).

SWRU346B

Page 26 of 114

CC120X
When using custom frequency modulation there are 129 values (referred to as fOFFSET) between −fdev
and +fdev that can be used (see Equation 1 and Equation 2 in Section 5.2.1 for details on how to
program the frequency deviation). fOFFSET is given by Equation 3.

f dev CFM _ TX _ DATA _ IN
[Hz]
64

fOFFSET

Equation 3: fOFFSET

The modulator writes values to the PLL at 16x the programmed symbol rate. Between the modulator
and the PLL there is an optional linear upsampler configured through the MDMCFG2.UPSAMPLER_P
register field.
5.2.5

DSSS PN Mode

CC120X supports DSSS PN mode for applications requiring high sensitivity. Preamble and sync word is
unchanged, but the payload data bit is spread with a fixed PN gold sequence initialized at the
beginning of each packet. The spreading factor is set to 4 hence the effective data rate is reduced by
a factor 4. The PN gold sequence is generated from a combination of two 7-bits LFSR registers with
generator polynomial given by Equation 4 and Equation 5. h1(p) is initialized to 0x04 and h2(p) is
initialized to 0x0B.

h1( p)

p 1

Equation 4: h1(p)

h2( p)

p3 1

Equation 5: h2(p)
The resulting bit is then XOR’ed with the transmitted bits, where each of the input data bits is mapped
into 4 consecutive symbols, as shown in the following Figure 11. The figure shows what is sent on the
air when the input data is 101b.
+
Input Data
@ ¼ Symbol Rate
Gold
Sequence

TX Data @ Symbol Rate

+
TX Data @ Symbol Rate

Bit n

Bit n + 1

Bit n + 2

Input Data @ ¼ Symbol Rate

Gold Sequence

Figure 11: Gold Sequence Generation
The resulting sequence has good autocorrelation properties.

This equation is only valid when -64 ≤ CFM_TX_DATA_IN ≤ +64. CFM_TX_DATA_IN > 64
corresponds to +fdev while CFM_TX_DATA_IN < -64 gives a frequency of −fdev. CFM_TX_DATA_IN
= -128 is the same as setting CFM_TX_DATA_IN = 0.

SWRU346B

Page 27 of 114

CC120X
At the receiver, the PN gold sequence is known and is initialized at the beginning of each packet. For
every group of 4 incoming symbols, two accumulated distance computation are performed; one
assuming that a ‘0’ was sent and the other assuming that a ‘1’ was sent, and the most likely
transmitted bit is chosen.
DSSS PN mode is enabled by setting MODCFG_DEV_E.MODEM_MODE = 10b8.
When using this mode both FIFO mode and synchronous serial mode are supported
(PKT_CFG2.PKT_FORMAT = 0 or 1).
5.2.6

DSSS Repeat Mode

CC120X supports DSSS repeat mode for applications requiring high sensitivity. In DSSS repeat mode,
preamble is unchanged. The payload data bits are spread using the sync word meaning that the
complete sync word is sent for every 1 in the payload and the inverted sync word is sent for every 0 in
the payload. Only SYNC_CFG1.SYNC_MODE = 1 and 010b are supported (11 or 16 bits).
DSSS repeat mode is enabled by setting MODCFG_DEV_E.MODEM_MODE = 18.
In TX mode all packet handling features are supported, but the packet format must be set to FIFO
mode (PKT_CFG2.PKT_FORMAT = 0).
In RX mode, none of the packet handling features are supported and synchronous serial mode must
be
selected
(PKT_CFG2.PKT_FORMAT
=
1,
MDMCFG1.FIFO_EN
=
0
and
MDMCFG0.TRANSPARENT_MODE_EN = 0). It is the MCU’s responsibility to extract the demodulated
data, which are available on GPIO by configuring IOCFGx.GPIOx_CFG = 18 (GPIO3/1 =
DSSS_CLK, GPIO2 = DSSS_DATA0 and GPIO0 = DSSS_DATA1). The clock (DSSS_CLK) will run at a
frequency twice the programmed symbol rate and will start as soon as the radio enters RX state.
The receiver uses two correlation filters (see Section 6.7 for more details) to search for sync word and
inverted sync word. Each output is connected directly to DSSS_DATA1 and DSSS_DATA0. After
strobing RX the sync search starts, and when a sync word or inverted sync word is detected the
corresponding serial data line will be asserted high, otherwise the data line is low. The output from the
correlation filter is high as long as the sync word/inverted sync word is detected, so the MCU needs to
do edge detect on the data in order to not duplicate the demodulated data bit. Figure 12 shows how
the DSSS signal will look like on the GPIO pins when the following packet is sent on the air using
DSSS repeat mode: 0x03, 0x55, 0x55, 0x55. Symbol rate is 1.2 ksps.
Note. Assertion of DSSS_DATA1 and DSSS_DATA0 within the first 5 DSSS_CLK edges after
entering RX should be ignored.

Figure 12: DSSS Repeat Mode

DSSS PN mode and DSSS repeat mode are not supported for 4’ary modulation formats.

SWRU346B

Page 28 of 114

CC120X
5.3

Forward Error Correction

FEC is enabled by settings PKT_CFG1.FEC_EN = 1. The FEC implemented in CC120X is compatible
with the 802.15.4g FEC (NRNSC coding) when PKT_CFG2.FS_MODE_EN = 1 and the FEC
implemented in the CC1101 when PKT_CFG2.FS_MODE_EN = 0.
The RXFIFO must not be accessed during packet reception when FEC is enabled, hence the
complete packet, excluding preamble and sync, must not be larger than 128 bytes. When using FEC,
the symbol rate must not exceed 250 ksps for 4’ary modulation formats or 500 ksps for 2’ary
modulation formats.
5.4

Symbol Rate Programming

The symbol rate used in transmit and the symbol rate expected in receive is programmed by the
SYMBOL_RATE_M and the SYMBOL_RATE_E configuration settings. The symbol rate, RSYMBOL, is given
by Equation 6 and Equation 7 and is in ksps. Note that SYMBOL_RATE_M is 20 bits wide and consists
of the register fields SRATE_M_19_16, SRATE_M_15_8 and SRATE_M_7_0 found in SYMBOL_RATE2,
SYMBOL_RATE1, and SYMBOL_RATE0 respectively.

RSymbol

(220 SRATE _ M ) 2 SRATE _ E
f XOSC [ksps]
239
Equation 6: Symbol Rate (SRATE_E > 0)

SRATE _ M
f XOSC [ksps]
238

RSymbol

Equation 7: Symbol Rate (SRATE_E = 0)
Equation 8 and Equation 9 can be used to find suitable register values for a given symbol rate.

SRATE _ E

log 2

RSymbol 239
f XOSC

Equation 8: SRATE_E

SRATE _ M

RSymbol 2 39
f XOSC 2

SRATE _ E

2 20

Equation 9: SRATE_M
20

If SYMBOL_RATE_M is rounded to the nearest integer and becomes 2 , one should increment
SYMBOL_RATE_E and use SYMBOL_RATE_M = 0 instead.
The symbol rate can be set up to 500 ksps with the minimum step size according to
Table 15.

SWRU346B

Page 29 of 114

CC120X
Min Symbol Rate [ksps]
0
0.15
0.61
1.22
2.44
4.88
19.5
39.0
78.1
156
312

Typical Symbol Rate [ksps]
0.04
0.25
1.2
2.4
4.8
9.6
25
50
100
250
500

Max Symbol Rate [ksps]
0.15
0.3
1.22
2.44
4.88
9.76
39.0
78.1
125
312
500

Symbol Rate Step Size [ksps]
0.00000014
0.00000014
0.0000006
0.000001
0.000002
0.000005
0.000018
0.000037
0.000074
0.00015
0.00029

Table 15: Symbol Rate Step Size
Note that for 4-(G)FSK, DSSS mode, Manchester mode, and FEC, the data rate and symbol rate is
not equal. Table 16 shows the relationship between data rate and symbol rate.
Modulation Format / Data Encoding
2-(G)FSK/OOK/ASK

Data Rate/Symbol Rate Ratio
RBit
RSymbol

Manchester Mode

RBit
RSymbol

1
2

4-(G)FSK

RBit
RSymbol

DSSS Mode

RBit
RSymbol

FEC

RBit
RSymbol

1
Spreading Factor
1
2

Table 16: Data Rate vs. Symbol Rate

6
6.1

Receive Configuration
RX Filter Bandwidth

In order to meet different channel width requirements, the RX filter BW is programmable. The
CHAN_BW.ADC_CIC_DECFACT and CHAN_BW.BB_CIC_DECFACT register fields control the RX filter
BW together with the crystal oscillator frequency. It is recommended to use SmartRF Studio [1] to
generate settings for a given RX filter BW.
Equation 10 gives the relation between the register settings and the RX filter bandwidth.
BB_CIC_DECFACT is found in CHAN_BW.

RX Filter BW

f xosc
[Hz]
Decimation Factor BB _ CIC _ DECFACT 2
Equation 10: RX Filter BW

SWRU346B

Page 30 of 114

CC120X
The decimation factor is 12, 24, or 48 depending on the CHAN_BW.ADC_CIC_DECFACT setting.
Table 17 lists the RX filter bandwidth configurations supported by the CC120X. The RX filter BW should
never be set higher than 1666.7 kHz. Note that values marked ( ) are only available on CC1200.
As a rule of thumb, one should set the decimation factor as high as possible for a given RX filter BW,
meaning that the preferred setting for 208.3 kHz is ADC_CIC_DECFACT = 2 and
BB_CIC_DECFACT = 2.
BB_CIC_DECFACT
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22

Decimation Factor
12
24
48
1666.7 833.3 416.7
833.3
416.7 208.3
555.6
277.8 138.9
416.7
208.3 104.2
333.3
166.7 83.3
277.8
138.9 69.4
238.1
119.0 59.5
208.3
104.2 52.1
185.2
92.6
46.3
166.7
83.3
41.7
151.5
75.8
37.9
138.9
69.4
34.7
128.2
64.1
32.1
119.0
59.5
29.8
111.1
55.6
27.8
104.2
52.1
26.0
98.0
49.0
24.5
92.6
46.3
23.1
87.7
43.9
21.9
83.3
41.7
20.8
79.4
39.7
19.8
75.8
37.9
18.9

BB_CIC_DECFACT
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44

Decimation Factor
12
24
48
72.5
36.2
18.1
69.4
34.7
17.4
66.7
33.3
16.7
64.1
32.1
16.0
61.7
30.9
15.4
59.5
29.8
14.9
57.5
28.7
14.4
55.6
27.8
13.9
53.8
26.9
13.4
52.1
26.0
13.0
50.5
25.3
12.6
49.0
24.5
12.3
47.6
23.8
11.9
46.3
23.1
11.6
45.0
22.5
11.3
43.9
21.9
11.0
42.7
21.4
10.7
41.7
20.8
10.4
40.7
20.3
10.2
39.7
19.8
9.9
38.8
19.4
9.7
37.9
18.9
9.5

Table 17: RX Filter BW in kHz
By compensating for a frequency offset between the transmitter and the receiver, the filter bandwidth
can be reduced and the sensitivity can be improved.
The following rule should be used when programming the RX filter BW:
SYNC_CFG0.RX_CONFIG_LIMITATION = 0:
o The RX filter BW must be larger or equal to twice the symbol rate
SYNC_CFG0.RX_CONFIG_LIMITATION = 1:
o The RX filter BW must be larger or equal to the symbol rate
A narrow bandwidth gives better sensitivity and selectivity at the cost of more accurate RF crystals.
The CHAN_BW.ADC_CIC_DECFACT sets the bandwidth into the digital low-IF mixer.
If the selected RX filter bandwidth is large compared to the symbol rate (10 times of more), sensitivity
can be improved by setting MDMCFG0.DATA_FILTER_EN = 1.
6.2

DC Offset Removal

CC120X

supports Low-IF and Zero-IF receiver architecture, which is set by the
IF_MIX_CFG.CMIX_CFG register field. For more information see section 9.12. For Zero-IF the DC
offset removal must be enabled by setting DCFILT_CFG.DCFILT_FREEZE_COEFF = 0. The
DCFILT_CFG configures the DC filter bandwidth, both during settling period and during tracking.
There is a tradeoff between bandwidth and settle time. Narrower DC filter bandwidth requires longer
settling time, but improves performance.
For best performance, use Low-IF receiver architecture when possible.

SWRU346B

Page 31 of 114

CC120X
6.3

Feedback to PLL

Register FREQOFF_CFG enables feedback to the PLL to "increase the RX filter BW". The noise
bandwidth, and hence sensitivity, will not increase when enabling this feature. Setting FREQOFF_CFG
to 0x30 and 0x34 enables feedback to the PLL and increases bandwidth from "programmed RX filter
BW" to "programmed RX filter BW ± RX filter BW/4" and "programmed RX filter BW ± RX filter BW/8"
respectively. As an example, RX filter BW is programmed to 33.3 kHz and FREQOFF_CFG = 0x30,
the feedback to PLL increases this filter to 50 kHz (although 33.3 kHz is still the noise bandwidth).
Figure 13 shows two plots of PER vs. input power level vs. frequency offset. In the first plot the RX
filter BW is programmed to 50 kHz and FREQOFF_CFG = 0x22 (i.e. feedback to PLL disabled). In
the second plot the RX filter BW is programmed to 33.3 kHz and FREQOFF_CFG = 0x30 (i.e.
feedback to PLL enabled). It is evident from the plots that the noise bandwidth is lower in the second
plot without the need to use a tighter tolerance crystal.

50 kHz
No feedback
to PLL

33.3 kHz
and feedback
to PLL

Figure 13: Feedback to PLL

SWRU346B

Page 32 of 114

CC120X
6.4

Automatic Gain Control

CC120X contains an Automatic Gain Control (AGC) for adjusting the input signal level to the
demodulator.
The AGC behavior depends on the following register fields:
AGC_CFG2.FE_PERFORMANCE_MODE
o Sets the correct gain tables to be applied for a given operation mode (See Table 18). See
the complete register description for what the different modes are.
~39
~36
~32
~29
~27
~24
~21
~18
~15
~12
~9
~6
~3
~0
~-6
~-12
~-18
~-21

dB
dB
dB
dB
dB
dB
dB
dB
dB
dB
dB
dB
dB
dB
dB
dB
dB
dB

Index 0
Index 1
Index 2

~27
~24
~21
~18
~15
~12
~9
~6
~3
~0
~-6
~-12
~-18
~-21

dB
dB
dB
dB
dB
dB
dB
dB
dB
dB
dB
dB
dB
dB

Index 0
Index 1
Index 2

~39
~32
~27
~21
~15
~9
~3
~0

dB
dB
dB
dB
dB
dB
dB
dB

Index 0
Index 1
Index 2

Index 7

Index 13

Index 17

FE_PERFORMANCE_MODE
= 0 or 1

FE_PERFORMANCE_MODE
= 10b

FE_PERFORMANCE_MODE
= 11b

Table 18: AGC Gain Tables
o The AGC_CFG2.AGC_MAX_GAIN and AGC_CFG3.AGC_MIN_GAIN register fields are used
to set the table indexes for maximum and minimum gain respectively. For example, setting
AGC_MAX_GAIN = 2 and AGC_MIN_GAIN = 15 limits the gain table to 14 entries, where
max gain is ~32 dB and min gain is ~-12 dB. A lower maximum gain will reduce power
consumption in the receiver front end, since the highest gain settings are avoided. Limiting
max gain also improves worst case linearity in the front-end, something that is very useful
when using external LNA.
AGC_REF.AGC_REFERENCE
o Sets the reference value for the AGC. The reference value is a compromise between
blocker tolerance/selectivity and sensitivity. The AGC reference level must be higher than
the minimum SNR to the demodulator. The AGC reduces the analog front end gain when
the magnitude output from the channel filter is greater than the AGC reference level. An
optimum AGC reference level is given by several conditions, but a rule of thumb is given by
Equation 11.

AGC_REFERENCE 10 log10 (RX FILTER BW) 92 RSSI_OFFSE T
9

Equation 11: AGC Reference

For Zero-IF configuration, AGC hysteresis > 3 dB, or modem format which needs SNR > 15 dB a
higher AGC reference value is needed

SWRU346B

Page 33 of 114

CC120X
AGC_CFG3.AGC_SYNC_BEHAVIOR
o Sets the AGC behavior and RSSI update behavior after a sync word is found
AGC_CFG1.AGC_WIN_SIZE
o Sets the AGC integration window size for each value. Samples refer to the RX filter
sampling frequency, which is 4 times the programmed RX filter BW
AGC_CFG1.AGC_SETTLE_WAIT
o Sets the wait time between AGC gain adjustments
AGC_CFG2.AGC_MAX_GAIN
o Sets the maximum gain
AGC_CFG3.AGC_MIN_GAIN
o Sets the minimum gain
See Figure 16 for detailed timing information on different AGC signals.
6.5

Image Compensation

CC120X has support for the ImageExtinct image compensation algorithm that digitally compensates for
I/Q mismatch. ImageExtinct removes the image component, removing any issues at the system image
frequency. ImageExtinct removes the need for time consuming image calibration steps in system
production test, reducing both test time and test cost. This feature is enabled by setting
IQIC.IQIC_EN = 1. When this feature is enabled, fIF > RX filter BW. Figure 14 shows selectivity
versus frequency with IQ image compensation enabled and disabled.

60
50
40
30
IQ Enabled

IQ Disabled

10
868.3

868.288

868.275

868.25

868.225

868.2

868.197

868.15

868.1

868.094

868.05

868,0000

867.9

0
867.8

Selectivity Relative [dM]

Frequency [MHz]
Figure 14: IQIC Enabled/Disabled (image at −206 kHz offset)

SWRU346B

Page 34 of 114

CC120X
6.6

Bit Synchronization

The bit synchronization algorithm extracts the clock from the incoming symbols. The algorithm
requires that the expected symbol rate is programmed as described in Section 5.3. Resynchronization is performed continuously to adjust for any offset between the incoming and
programmed symbol rate.
It is possible to select between two different bit synchronization algorithms.
TOC_CFG.TOC_LIMIT sets the bit synchronization algorithm and Table 19 below shows the
properties of the bit synchronization algorithms.
TOC_LIMIT
0
1
2
3

Symbol Rate Offset Tolerance
< 0.2 %
<2%
Reserved
< 12 %

Required Preamble Length
0.5 byte (only for gain adjustment)
2 - 4 bytes
2 - 4 bytes

Table 19: Bit Synchronization Property
Using the low tolerance setting (TOC_LIMIT = 0) greatly reduces system settling times and system
power consumption as no preamble bits are needed for bit synchronization or frequency offset
compensation (4 bits preamble needed for AGC settling).
6.7

Byte Synchronization, Sync Word Detection

Byte synchronization is achieved by a continuous sync word search using the novel WaveMatch
capture logic (correlation filter). The sync word is configured through the SYNC3/2/1/0 registers and
can be programmed to be 11, 16, 18, 24 or 32 bits. This is done through the
SYNC_CFG1.SYNC_MODE register field. In TX mode, these bits are automatically inserted at the start
of the packet by the modulator. The MSB in the sync word is sent first. In RX mode, the demodulator
uses the sync word to find the start of the incoming packet.
The CC120X will continuously calculate a sync word qualifier value to distinguish the sync word from
background noise. This value is available in the PQT_SYNC_ERR.SYNC_ERROR register field. If the
sync word qualifier value is less than the programmed sync threshold (SYNC_CFG1.SYNC_THR)
divided by 2 the demodulator starts to demodulate the packet.
The CC120X supports DualSync search which makes it possible to concurrently search for 2 different
16 bit sync words. DualSync search is enabled by settings SYNC_CFG1.SYNC_MODE = 111b. As
soon as one of the sync words is found, the RX FIFO starts to fill up.
In addition to continuously calculating a sync word qualifier value the CC120X has several other
features that can be used to decrease the likelihood of detecting “false” packets.
Strict Sync Word Bit Check
This feature is enabled through SYNC_CFG0.STRICT_SYNC_CHECK and allows for additional
bit check on sync word. This feature is especially useful if the sync word used has weak
correlation properties. There are three levels of the strict sync check, where level 3 is the
setting that allows for the least amount of error in the sync word (the strictest setting). Setting
STRICT_SYNC_CHECK = 11b disables this feature and is the settings that will give the best
sensitivity.
Carrier Sense Gating
When MDMCFG1.CARRIER_SENSE_GATE = 1, the demodulator will not start to look for a sync
word before CARRIER_SENSE is asserted. See Section 6.9.1 for more details on CS.
PQT Gating
When SYNC_CFG0.PQT_GATING_EN = 1, the demodulator will not start to look for a sync
word before a preamble is detected. The preamble detector must be enabled for this feature to
work (PREAMBLE_CFG0.PQT_EN = 1). See Section 6.8 for more details on PQT.

SWRU346B

Page 35 of 114

CC120X
6.8

Preamble Detection

CC120X has a high performance preamble detector which can be turned on by setting
PREAMBLE_CFG0.PQT_EN = 1.
The preamble quality estimator uses an 8 bits wide correlation filter to find a valid preamble. A
preamble qualifier value is available through the PQT_SYNC_ERR.PQT_ERROR register field while the
threshold is configured with the register field PREAMBLE_CFG0.PQT.
A preamble is detected if the preamble qualifier value is less than the programmed PQT threshold. A
“Preamble Quality Reached” signal can be observed on one of the GPIO pins by setting
IOCFGx.GPIOx_CFG = PQT_REACHED (11). It is also possible to determine if preamble quality is
reached by checking the PQT_REACHED bit in the MODEM_STATUS1 register. The PQT_REACHED
signal will stay asserted as long as a preamble is present but will de-assert on sync found. If the
preamble disappears, the signal will de-assert after a timeout defined by the sync word length + 10
symbols after preamble was lost. When SYNC_CFG0.PQT_GATING_EN = 1, sync word search is
only gated if a preamble is detected.
The PQT can also be used as a qualifier for the optional RX termination timer (see Section 9.5.1 for
more details).
A
PQT
startup
timer
is
available
and
programmable
through
the
PREAMBLE_CFG0.PQT_VALID_TIMEOUT register. The PQT response time is the time it takes from
entering RX mode until PQT_VALID is asserted. The PQT response time is given by Equation 12,
where T0 is given by Equation 18 and T1 is given by Equation 13 or Equation 14 depending on the
SYMBOL_RATE2.SRATE_E setting. BB_CIC_DECFACT is found in register CHAN_BW and the
decimation factor is 12, 24, or 48, given by the CHAN_BW.ADC_CIC_DECFACT register field. SRATE_E
and SRATE_M are found in the SYMBOL_RATEn registers (where n = 0, 1, 2) and
RX_CONFIG_LIMITATION is found in SYNC_CFG0. In Equation 13 or Equation 14, x = Decimation
Factor·BB_CIC_DECFACT.

PQT Response Time

T 0 T1

Equation 12: PQT Response Time

FLOOR

238 PQT Startup Timer (2 RX _ CONFIG _ LIMITATION
SRATE _ M x
2 .RX _ CONFIG _ LIMITATION

1
56

1
f XOSC

Equation 13: T1 when SRATE_E = 0

x
T1

FLOOR

239 PQT Startup Timer (2 RX _ CONFIG _ LIMITATION
( SRATE _ M 2 20 ) SRATE _ E x
2 .RX _ CONFIG _ LIMITATION

2)
56

1
f XOSC

Equation 14: T1 when SRATE_E ≠ 0

The different PQT startup timer values enables a tradeoff between speed and accuracy as preamble
search will not be gated before PQT_VALID is asserted. PQT_VALID can be monitored on a GPIO pin
by setting IOCFGx.GPIOx_CFG = PQT_VALID (12).

SWRU346B

Page 36 of 114

CC120X
6.9

RSSI

The AGC module returns an estimate on the signal strength received at the antenna called RSSI
(Received Signal Strength Indicator). The RSSI is a 12 bits two's complement number with 0.0625 dB
resolution hence ranging from –128 to 127 dBm. A value of –128 dBm indicates that the RSSI is
invalid. The RSSI can be found by reading RSSI1.RSSI_11_4 and RSSI0.RSSI_3_0. It should be
noted that for most applications using the 8 MSB bits of the RSSI, with 1 dB resolution, is good
enough.
To get a correct RSSI value a calibrated RSSI offset value should be added to the value given by
RSSI[11:0] (the RSSI offset will be a negative number). The RSSI offset value can be found by
input a signal of known strength to the radio when AGC_GAIN_ADJUST.GAIN_ADJUSTMENT is
10
0x00 .
Example:
Assume a -65 dBm signal into the antenna and RSSI[11:0]
AGC_GAIN_ADJUST.GAIN_ADJUSTMENT = 0x00.

0x220 (34) when

This means that the offset is −99 dB as 34 dBm + (–99) dB = –65 dBm.
When the offset is known it can be written to the AGC_GAIN_ADJUST.GAIN_ADJUSTMENT
register field (GAIN_ADJUSTMENT = 0x9D (−99)). When the same signal is input to the antenna,
the RSSI[11:0] register will be 0xBF0 (–65).
The RSSI value is output from a configurable moving average filter in order to reduce uncertainty in
the RSSI estimates. It is as such possible to trade RSSI computation speed/update rate against RSSI
accuracy. This trade-off is determined by configuring the AGC_CFG0.RSSI_VALID_CNT register. This
register field gives the number of new input samples to the moving average filter (internal RSSI
11
estimates) that are required before the next update of the RSSI value . The RSSI_VALID signal will
be asserted from the first RSSI update. RSSI_VALID is available on a GPIO by setting
IOCFGx.GPIOx_CFG = RSSI_VALID (13) or can be read from the RSSI0 register.
Carrier Sense (CS) indication will also be affected by the setting of AGC_CFG0.RSSI_VALID_CNT.
After the RSSI is valid it will be continuously compared to the CS threshold set in the AGC_CS_THR
register, but since the RSSI update rate is given by the RSSI_VALID_CNT register field, this will in
practice limit the CS update rate as well. The exception is when the CS threshold is changed while in
RX mode. The CARRIER_SENSE signal will then be updated immediately (if needed). For more info
on CS, see Section 6.9.1. Figure 15 shows when CS is updated with respect to the RSSI.
Signal Strength
CS Threshold
RSSI
CARRIER_SENSE
Time
RSSI Update

Figure 15: CS vs. RSSI_UPDATE
Figure 16 shows an example of the behavior of RSSI specific signals given two different values for the
AGC_CFG0.RSSI_VALID_CNT register value (1 and 10b).

The RSSI offset changes if MDMCFG1.DVGA_GAIN is changed

By setting the IOCFG3.GPIO3_CFG or IOCFG2.GPIO2_CFG = RSSI_UPDATE (14), a pulse
will occur on GPIO3 or GPIO2 each time the RSSI value is updated

SWRU346B

Page 37 of 114

CC120X
MARCSTATE

IDLE

AGC State

IDLE

Frontend Gain

G_MAX

#10

#11

#12

#13

#14

#15

G_1 < G_MAX

AGC_UPDATE

Internal RSSI Estimate

AGC_STABLE_GAIN

AGC_HOLD

RSSI_VALID_CNT

01b

RSSI[11:0]

-128

RSSI_UPDATE

CARRIER_SENSE

CARRIER_SENSE_VALID

RSSI_VALID_CNT

10b

RSSI[11:0]

-128

RSSI_UPDATE

CARRIER_SENSE

CARRIER_SENSE_VALID

Time Intervals

T0-T3

T2+T3

Carrier Sense Response Time

T2+T3

Time

Figure 16: RSSI/CS Timing Diagram

SWRU346B

Page 38 of 114

CC120X
T0: Start-up delay before RSSI measurements can begin. This delay is dependent on demodulator
settings and can be found using Table 21, Table 22, and Equation 18.
T1: The time the AGC waits after adjusting the front end gain to allow signal transients to decay
before the next signal strength measurement can take place. T1 can be calculated using Equation 15.
T2: The time the AGC uses to measure the signal strength and potentially adjust the gain. T2 can be
calculated using Equation 16.
T3: Pipeline delay. T3 can be calculated using Equation 17.
The CS response time is the time it takes before CARRIER_SENSE_VALID is asserted. This is the
maximum time the radio will be in RX state when RX termination based on CS is enabled (see
Section 9.5.2 for more details). The CS response time is given by Equation 19.
Figure 16 shows an example of how RSSI computation speed/update rate can be traded against
RSSI accuracy. In the case where AGC_CFG0.RSSI_VALID_CNT = 1 the number of new input
samples to the moving average filter is 2, making the CS response time short but might lead to a less
robust CS indication on the second RSSI update. In the case where AGC_CFG0.RSSI_VALID_CNT
= 10b (5 samples) there are no failing CS, but the response time is longer.
12

BB_CIC_DECFACT is found in register CHAN_BW while AGC_SETTLE_WAIT and AGC_WIN_SIZE
register fields are found in the AGC_CFG1 register. DCFILT_FREEZE_COEFF and
DCFILT_BW_SETTLE are found in DCFILT_CFG. The decimation factor is 12, 24, or 48, given by the
CHAN_BW.ADC_CIC_DECFACT register field and CMIX_CFG is found in the IF_MIX_CFG register.
RSSI_VALID_COUNT is found in AGC_CFG0 and IQIC_EN is found in IQIC.
The notation m(register field name) means the value in the description field that match the bit pattern.
For example, m(RSSI_VALID_COUNT) = 9 if RSSI_VALID_COUNT = 11b.

m( AGC _ SETTLE _ WAIT ) BB _ CIC _ DECFACT Decimation Factor
[s]
RSSI Update Rate Scale Factor f xosc
Equation 15: T1

2( 3

AGC _ WIN _ SIZE )

BB _ CIC _ DECFACT Decimation Factor
[s]
RSSI Update Rate Scale Factor f xosc
Equation 16: T2

T 3 CEILING

t Sample Period

tSample Period

f xosc

[s]

, where

BB _ CIC _ DECFACT Decimation Factor
RSSI Update Rate Scale Factor f xosc
Equation 17: T3

If BB_CIC_DECFACT = 0, use a value of 1

SWRU346B

Page 39 of 114

CC120X
In Equation 15, Equation 16, and Equation 17, the RSSI update rate scale factor is given by
SYNC_CFG0.RX_CONFIG_LIMITATION as shown in Table 20.
RX_CONFIG_LIMITATION

RSSI Update Rate Scale Factor

0
1

2
4

Table 20: RSSI Update Rate Scale Factor
Configuration Register Fields/Conditions
CHAN_BW.BB_CIC_DECFACT > 0x01

0
1

D0 + D1 + D2 + D3
D0 + D1 + D2 + D3 + D4

Table 21: T0 Matrix
Delay
D0

Equation (all delays are given in seconds)

D113

(1 DCFILT _ FREEZE _ COEFF ) (2 ( x
f XOSC

12 BB _ CIC _ DECFACT Decimation Factor
f XOSC

D314

2 IQIC _ EN
f XOSC

(15 BB _ CIC _ DECFACT 2) Decimation Factor
f XOSC

8 Decimation Factor 20
f XOSC
3)

1) Decimation Factor
6

y 4
6

Table 22: D0 – D4

Applicable Delays |Current Configurat ion
Equation 18: T0

The maximum carrier sense response time is given by Equation 19.

CS Response Time

T0 (T1 T2 T3 ) m( RSSI _ VALID _ COUNT ) T 3

10
f xosx

Equation 19: Max CS Response Time [s]
If number of AGC_UPDATE pulses before the first RSSI update is known, the CS response time is
given by Equation 20.

CS Response Time

T0 T1 x (T2 T3 ) m( RSSI _ VALID _ COUNT ) T 3

10
f xosx

Equation 20: CS Response Time [s] (# of gain reductions is known)
In cases where AGC_CFG1.AGC_SYNC_BEHAVIOR is set to freeze the RSSI value after a sync word
is detected, it is important that preamble and sync word is long enough so that the RSSI represent the
RSSI of the packet and not of noise received prior to the preamble.

x = DCFILT_CFG.DCFILT_BW_SETTLE when DCFILT_CFG.DCFILT_BW_SETTLE < 5,

else it is 4
14

y = 0 when IF_MIX_CFG.CMIX_CFG = 0 or 100b, else it is 1

SWRU346B

Page 40 of 114

CC120X
Assume a symbol rate of 2.4 ksps and the following register configurations:
CHAN_BW.ADC_CIC_DECFACT = 2
CHAN_BW.BB_CIC_DECFACT = 38
AGC_CFG1.AGC_WIN_SIZE = 2
AGC_CFG0.RSSI_VALID_CNT = 1
AGC_CFG1.SETTLE_WAIT = 1
SYNC_CFG0.RX_CONFIG_LIMITATION = 0
Equation 19 can be used to find the max RSSI update rate. For this example it is assumed that the
radio has been in RX for some time before a packet is received so T0 can be ignored.

RSSI Update Rate (T1 T2 T3 ) m( RSSI _ VALID _ COUNT ) T 3

10
f xosx

m( AGC _ SETTLE _ WAIT ) BB _ CIC _ DECFACT Decimation Factor
RSSI Update Rate Scale Factor f xosc

2( 3

AGC _ WIN _ SIZE )

BB _ CIC _ DECFACT Decimation Factor
RSSI Update Rate Scale Factor f xosc

t Sample Period

BB _ CIC _ DECFACT Decimation Factor
RSSI Update Rate Scale Factor f xosc

T 3 CEILING

48
22.8 10

RSSI Update Rate
(729 10

729 10

(T1 T2
6

22.8 10
f xosc

38 48
2 40 106

32 38 48
2 40 106

2(3 2) 38 48
2 40 106
22.8 10

729.6 μs

1.2 μs

T3 ) m( RSSI _ VALID _ COUNT ) T 3

1.2 10 6 ) 2 1.2 10

10
40 106

10
f xosx

2.92 ms

To guarantee that the RSSI measurement is done during the packet and not on noise, preamble +
sync word should be greater than twice the RSSI update rate.
With a symbol rate of 2.4 ksps this means that a minimum of 14 bits preamble/sync must be received
for the RSSI readout to be correct (assume that RBit/RSymbol = 1). For this example it is assumed that
the radio has been in RX for a time longer than the max CS response time (see Equation 19) when
the preamble and sync word is received.

SWRU346B

Page 41 of 114

CC120X
6.9.1

Carrier Sense (CS)

Carrier Sense (CS) is asserted when the RSSI is above a programmable CS threshold, AGC_CS_THR,
and de-asserted when RSSI is below the same threshold. The CS threshold should be set high
enough so that CS is de-asserted when only background noise is present and low enough so that CS
is asserted when a wanted signal is present. Different usage of CS includes:
Sync word qualifier: When MDMCFG1.CARRIER_SENSE_GATE = 1, the demodulator will not
start to look for a sync word before CS is asserted
Clear Channel Assessment (CCA) and TX on CCA
Avoid interference from other RF sources in the ISM band
RX termination
The latter is described in Section 9.5. By setting the IOCFGX.GPIOX_CFG = CARRIER_SENSE (17),
GPIOx will indicate if a carrier is present. The CS signal is evaluated each time a new internal RSSI
estimate is computed. The CARRIER_SENSE signal must only be interpreted when it is valid, as
indicated by CARRIER_SENSE_VALID. This signal can be routed to GPIOX by setting
IOCFGX.GPIOX_CFG = CARRIER_SENSE_VALID (16) to help evaluate this in real-time. The two
signals can also be read from the RSSI0 register.
6.10 Collision Detector
If a packet is currently being received by the radio (data is put in the RX FIFO) when a preamble is
found with a RSSI 10 or 16 dB higher than the RSSI at the time when SYNC_EVENT was asserted, a
collision has found place (COLLISION_FOUND is asserted). A collision can be handled in several
different ways.
Not handled. The current packet received will have errors and can be discarded. This method
will work well in most systems as RF protocols have capabilities for re-transmissions to solve
these issues.
RX can be terminated and resumed later.
RX can be restarted to receive the new packet (this scenario is mainly for high throughput
protocols where nodes communicate with several nodes at various distances). The SRX strobe
can be used to immediately restart the demodulator to catch the incoming packet. Since an
SFRX strobe cannot be issued from RX state one should read the NUM_RXBYTES register to
find out how many bytes belong to the first packet. CC120X has several signals that can be used
to
indicate
a
collision.
These
are
RSSI_STEP_FOUND,
RSSI_STEP_EVENT,
COLLISION_FOUND, and COLLISION_EVENT described in Table 10.
6.11 Clear Channel Assessment (CCA)
The Clear Channel Assessment (CCA) is used to indicate if the current channel is free or busy. The
current CCA state is viewable on GPIO1 or GPIO3 by setting IOCFG1/3.GPIO1/3_CFG =
CCA_STATUS (15). There are also two other flags related to the CCA feature available. These are
TXONCCA_DONE and TXONCCA_FAILED and are available on GPIO2 and GPIO0 respectively by
using the same IOCFG configuration as for CCA_STATUS. TXONCCA_DONE is a pulse occurring when
a decision has been made as to whether the channel is busy or not and TXONCCA_FAILED indicates
if the radio went to TX or not after TXONCCA_DONE was asserted.
PKT_CFG2.CCA_MODE selects the mode to use when determining CCA.
When an STX or SFSTXON command strobe is given while CC120X is in the RX state, the TX or
FSTXON state is only entered if the clear channel requirements are fulfilled (CCA_STATUS is
asserted). Otherwise, the chip will remain in RX. If the channel then becomes available, the radio will
15
not enter TX or FSTXON state before a new strobe command is sent on the SPI interface . This
feature is called TX on CCA/LBT. Five CCA requirements can be programmed:

If PKT_CFG2.CCA_MODE = 100b (LBT) the radio will try to enter TX mode again automatically
until the channel is clear and TX mode is being entered

SWRU346B

Page 42 of 114

CC120X
Always (CCA disabled, always goes to TX)
If RSSI is below threshold
Unless currently receiving a packet
Both the above (RSSI below threshold and not currently receiving a packet)
If RSSI is below threshold and ETSI LBT [2] requirements are met
6.12 Listen Before Talk (LBT)
ETSI EN 300 220-1 V2.3.1 [2] has specific requirements for LBT. To simplify compliance CC120X has
built in HW support to automate the LBT algorithm, including random back-offs. The requirements are
taken from the ETSI specifications, and a summary is shown below.
6.12.1 LBT Minimum Listening Time
“The minimum listening time is defined as the minimum time that the equipment listens for a received
signal at or above the LBT threshold level (…..) immediately prior to transmission to determine
whether the intended channel is available for use.
The listening time shall consist of the "minimum fixed listening time" and an additional pseudo random
part. If during the listening mode another user is detected on the intended channel, the listening time
shall commence from the instant that the intended channel is free again. Alternatively, the equipment
may select another channel and again start the listen time before transmission.”
Changing channel is not supported in HW and must be performed by the MCU.
6.12.2 Limit for Minimum Listening Time
“The total listen time, tL, consists of a fixed part, tF, and a pseudo random part, tPS, as the following:
tL = tF + tPS
a) The fixed part of the minimum listening time, tF, shall be 5 ms.
b) The pseudo random listening time tPS shall be randomly varied between 0 ms and a value of 5
ms or more in equal steps of approximately 0,5 ms as the following:
If the channel is free from traffic at the beginning of the listen time, t L, and remains free
throughout the fixed part of the listen time, tF, then the pseudo random part, tPS, is
automatically set to zero by the equipment itself.
If the channel is occupied by traffic when the equipment either starts to listen or during the
listen period, then the listen time commences from the instant that the intended channel is
free. In this situation the total listen time tL shall comprise tF and the pseudo random part,
tPS.
The limit for total listen time for the receiver consists of the sum of a) and b) together.”
If LBT is enabled (PKT_CFG2.CCA_MODE = 100b) the CC120X will run the algorithm until successful
transmission.
6.13 Link Quality Indicator (LQI)
The Link Quality Indicator is a metric of the current quality of the received signal. If
PKT_CFG1.APPEND_STATUS is enabled, the value is automatically added to the last byte appended
after the payload. The value can also be read from the LQI_VAL register. The LQI gives an estimate
of how easily a received signal can be demodulated. LQI is best used as a relative measurement of
the link quality (a low value indicates a better link than what a high value does), since the value is
dependent on the modulation format.

SWRU346B

Page 43 of 114

CC120X
7
7.1

Transmit Configuration
PA Output Power Programming

PA power ramping is used to improve spectral efficiency of the system by reducing the out of band
signal energy created by abrupt changes in the output power. PA output power ramping is used when
starting/ending a transmission and is enabled by setting PA_CFG1.PA_RAMP_SHAPE_EN = 1. The
power ramping is very flexible and can be controlled by a configurable, piecewise linear function.
The RF output power level from the device is programmed with the PA_CFG1.PA_POWER_RAMP
register field. The power level resolution is 0.5 dB.

Output Power

PA _ POWER _ RAMP 1
18 [dBm]
2
16

Equation 21: Output Power
Where 3 ≤ PA_POWER_RAMP ≤ 64

The shaped power ramping is controlled by the PA_CFG0 register. The shaped power ramp up curve
passes through two intermediate power levels from off-state to programmed output power level
(PA_CFG1.PA_POWER_RAMP). The intermediate power levels and total ramp time can be
configured. For the shaped ramp up the output power level is split into 16 sections (see Figure 17
where 1 equals the output power level). The two intermediate power levels are defined using these 16
sections. The first intermediate power level can be programmed within the power level range 0 - 7/16
through PA_CFG0.FIRST_IPL. The second intermediate power level can be programmed within
power range of 0.5 - 15/16 through PA_CFG0.SECOND_IPL. In Figure 17, FIRST_IPL = 011b and
SECOND_IPL = 110b.

Configurable ramping levels

●
●

●

8/16

●
●
0

●

1/3

2/3

Configurable: 3/8, 3/2, 3, 6 Ts
Figure 17: PA Power Ramping Control (configurable in the grey area)
3

The PA ramp up time (and ramp down time) is /8, /2, 3, or 6 symbols and is configured through
PA_CFG0.PA_RAMP_SHAPE.

This equation is an approximation. SmartRF Studio provides recommended values for different
output powers based on characterization.

SWRU346B

Page 44 of 114

CC120X
7.2

OOK/ASK Bit Shaping

When using OOK/ASK bit shaping is enabled by setting PA_CFG1.PA_RAMP_SHAPE_EN = 1 and
1
1
1
1
the the OOK/ASK shape length is /32, /16, /8, or /4 symbols (configured through
PA_CFG0.PA_RAMP_SHAPE). The resolution of an ASK bit transition is given by
1
MDMCFG2.ASK_SHAPE. Figure 18 shown the shaping of an ASK bit when the shape length is /8 and
the resolution is 8.

Amplitude
AMax

PA_RAMP_SHAPE_EN = 0

AMin
Time
AMax

1/8
PA_RAMP_SHAPE_EN = 1
RAMP_SHAPE = 10b
ASK_SHAPE = 0

AMin
Time
Figure 18: OOK/ASK Bit Shaping Configuration

SWRU346B

Page 45 of 114

CC120X
8

Packet Handling Hardware Support

The CC120X has built-in hardware support for packet oriented radio protocols.
In transmit mode, the packet handler can be configured to add the following elements to the packet
stored in the TX FIFO:
A programmable number of preamble bytes
An 11, 16, 18, 24 or 32 bit synchronization word
A 2 byte CRC checksum computed over the data field.
Whitening of the data with a PN9 sequence
In receive mode, the packet handling support will de-construct the data packet by implementing the
following (if enabled):
Preamble detection
Sync word detection
CRC computation and CRC check
One byte address check
Packet length check (length byte checked against a programmable maximum length)
De-whitening
Optionally, two status bytes (see Table 23 and Table 24) with RSSI value, Link Quality Indication, and
CRC status can be appended in the RX FIFO by setting PKT_CFG1.APPEND_STATUS = 1.
Bit
7:0

Field Name
RSSI

Description
RSSI value

Table 23: Received Packet Status Byte 1
(first byte appended after the data)
Bit
7

Field Name
CRC_OK

6:0

LQI

Description
1: CRC for received data OK
(or CRC disabled or TX mode)
0: CRC error in received data
Indicating the link quality

Table 24: Received Packet Status Byte 2
(second byte appended after the data)
8.1

Standard Packet Format

The format of the data packet can be configured and consists of the following items (see Figure 19):
Preamble
Synchronization word
Optional length byte
Optional address byte
Payload
Optional 2 byte CRC
Optional data whitening

Legend:
Inserted automatically in TX,
processed and removed in RX.

Data field

max 32
bits

8
bits

8 x n bits

CRC-16

Address field

8 x n bits

Length field

Preamble bits

Sync word

Optional CRC-16 calculation

Optional user-provided fields processed in TX,
processed but not removed in RX.
Unprocessed user data (apart from
whitening)

16 bits

Figure 19: Packet Format

SWRU346B

Page 46 of 114

CC120X
The preamble pattern is an alternating sequence of ones and zeros (1010∙∙/0101∙∙/
00110011∙∙/11001100∙∙) programmable through the PREAMBLE_CFG1.PREAMBLE_WORD register
field.
The
minimum
length
of
the
preamble
is
programmable
through
the
PREAMBLE_CFG1.NUM_PREAMBLE register field. When strobing TX, the modulator will start
transmitting a preamble. When the programmed number of preamble bytes has been transmitted, the
modulator will send the sync word and then data from the TX FIFO. If the TX FIFO is empty, the
modulator will continue to send preamble bytes until the first byte is written to the TX FIFO. The
modulator will then send the sync word and then the data bytes.
The sync word is set in the SYNC3/2/1/0 registers. The sync word provides byte synchronization of
the incoming packet. Non-supported sync word lengths can be emulated by using parts of the
preamble pattern in the SYNC registers.

CC120X supports both fixed packet length protocols and variable packet length protocols. Variable or
fixed packet length mode can be used for packets up to 255 bytes. For longer packets, infinite packet
length mode must be used. The packet length is defined as the payload data and the optional address
byte, excluding the optional length byte, the optional CRC, and the optional append status.
8.1.1

Fixed Packet Length

Fixed packet length mode is selected by setting PKT_CFG0.LENGTH_CONFIG = 00. The desired
packet length is set by the PKT_LEN register.
To support non-byte oriented protocols, fixed packet length mode supports packet lengths of n bytes
+ m bits, where n is programmed through the PKT_LEN register and m is programmed through
PKT_CFG0.PKT_BIT_LEN. If m ≠ 0, only m bits of the last byte written to the TX FIFO is transmitted
and RX mode is terminated when the last m bits of the packet is received. This is very useful in low
power systems where it is important not to stay in TX/RX longer than necessary. CRC is not
supported when PKT_CFG0.PKT_BIT_LEN ≠ 0. In RX, you will read zero’s from the (8 − m) LSBs in
the last byte in the RX FIFO.
Note: If PKT_LEN = 0x00 and PKT_CFG0.PKT_BIT_LEN ≠ 000 the packet length is between 1
and 7 bits long (given by the PKT_BIT_LEN register field). If PKT_LEN = 0x00 and
PKT_CFG0.PKT_BIT_LEN = 000 the packet length is 256 bytes.
8.1.2

Variable Packet Length

In variable packet length mode, PKT_CFG0.LENGTH_CONFIG = 01, the packet length is configured
by the first byte after the sync word. The packet length is defined as the payload data and optional
address field, excluding the length byte and the optional CRC. The PKT_LEN register is used to set
the maximum packet length allowed in RX. Any packet received with a length byte with a value
greater than PKT_LEN will be discarded.
By setting PKT_CFG0.LENGTH_CONFIG = 11b only the 5 LSB of the length byte is used for length
configuration while the 3 MSB are treated as normal data. Maximum packet length is hence 32 bytes.
The only difference from standard variable length mode is the masking of 3 MSB bits of the received
packet length byte, configured through LENGTH_CONFIG.
8.1.3

Infinite Packet Length

With PKT_CFG0.LENGTH_CONFIG = 10b, the packet length is set to infinite and transmission and
reception will continue until turned off manually. As described in the next section, this can be used to
support packet formats with different length configuration than natively supported by CC120X.
Note: The minimum packet length supported (excluding the optional length byte and CRC) is
one byte of payload data.

SWRU346B

Page 47 of 114

CC120X
8.1.4

Arbitrary Length Field Configuration

The packet length register, PKT_LEN, can be reprogrammed during receive and transmit (this is also
the case for the PKT_BIT_LEN register field in the PKT_CFG0 register). In combination with fixed
packet length mode (PKT_CFG0.LENGTH_CONFIG = 0) this opens the possibility to have a different
length field configuration than supported for variable length packets (in variable packet length mode
the length byte is the first byte after the sync word). At the start of reception, the packet length is set
to a large value. The MCU reads out enough bytes to interpret the length field in the packet. Then the
PKT_LEN value is set according to this value. The end of packet will occur when the byte counter in
the packet handler is equal to the PKT_LEN register. Thus, the MCU must be able to program the
correct length before the internal counter reaches the packet length.
8.1.5

Packet Length > 255

PKT_CFG0.LENGTH_CONFIG can also be reprogrammed during TX and RX. This opens the
possibility to transmit and receive packets that are longer than 256 bytes and still be able to use the
packet handling hardware support. At the start of the packet, the infinite packet length mode
(PKT_CFG0.LENGTH_CONFIG = 10b) must be active. On the TX side, the PKT_LEN register is set
to mod(length, 256). On the RX side the MCU reads out enough bytes to interpret the length field in
17
the packet and sets the PKT_LEN register to mod(length, 256) . When less than 256 bytes remains
of the packet, the MCU disables infinite packet length mode and activates fixed packet length mode
(PKT_CFG0.LENGTH_CONFIG = 0). When the internal byte counter reaches the PKT_LEN value,
the transmission or reception ends (the radio enters the state determined by
RFEND_CFG0.TXOFF_MODE or RFEND_CFG1.RXOFF_MODE). Automatic CRC appending/checking
can also be used (by setting PKT_CFG1.CRC_CFG ≠ 0).
When for example a 600-byte packet is to be transmitted, the MCU should do the following.
Set PKT_CFG0.LENGTH_CONFIG = 2
Pre-program the PKT_LEN register to mod(600, 256) = 88
Transmit at least 345 bytes (600 − 255), for example by filling the 128-byte TX FIFO three times
(384 bytes transmitted)
Set PKT_CFG0.LENGTH_CONFIG = 0
The transmission ends when the packet counter reaches 88. A total of 600 bytes are
transmitted.

Internal byte counter in packet handler counts from 0 to 255 and then starts from 0 again
0 , 1 ,.......... ,88 , .................... 255 , 0 , ........ , 88 , .................. , 255 ,0 , ........ , 88 ,.................. , 255 , 0 , .......................

Infinite packet length enabled

Fixed packet length
enabled when less than 256
bytes remains of the packet

600 bytes transmitted or received

Length field transmitted and received. RX and TX PKT_LEN value set to mod(600, 256) = 88)

Figure 20: Packet Length > 255

Given two positive numbers, a dividend x and a divisor y, mod(x, y) can be thought of as the
remainder when dividing x by y. For instance, the expression mod(5, 4) would evaluate to 1 because
5 divided by 4 leaves a remainder of 1

SWRU346B

Page 48 of 114

CC120X
8.1.6

Data Whitening

From a radio perspective, the ideal over the air data are random and DC free. This results in the
smoothest power distribution over the occupied bandwidth. This also gives the regulation loops in the
receiver uniform operation conditions (no data dependencies).
Real data often contain long sequences of zeros and ones making it difficult to track the data bits. In
these cases, performance can be improved by whitening the data before transmitting, and dewhitening the data in the receiver.
With CC120X, this can be done automatically. By setting PKT_CFG1.WHITE_DATA = 1, all data,
except the preamble and the sync word will be XORed with a 9-bit pseudo-random (PN9) sequence
before being transmitted. This is shown in Figure 21. At the receiver end, the data are XORed with the
same pseudo-random sequence. In this way, the whitening is reversed, and the original data appear
in the receiver. The PN9 sequence is initialized to all 1’s. By setting PKT_CFG1.PN9_SWAP_EN = 1,
the PN9 sequence can be swapped before whitening/de-whitening. This can only be done when the
radio is using standard packet mode (PKT_CFG2.FG_MODE_EN = 0).
If CC120X is set up to transmit random data, the PN9 whitening sequence will be transmitted
(see Table 25).

TX_DATA

The first TX_DATA byte is shifted in before doing the XOR-operation providing the first TX_OUT[7:0] byte. The
second TX_DATA byte is then shifted in before doing the XOR-operation providing the second TX_OUT[7:0] byte.
TX_OUT[7:0]

Figure 21: Data Whitening in TX Mode
Assume the following bytes should be transmitted: 0xAB, 0x80, 0xFF, 0x00
The first byte is XORed with 0xFF (initial value)
0xAB ⊕ 0xFF = 0x54
Table 25 shows how the bit shifting and XORing of bit 5 and bit 0 gives the bytes that the remaining
bytes in the packet should be XORed with.

SWRU346B

Page 49 of 114

CC120X
8 (5 ⊕ 0)
1
0
0
0
0
1
1
1
1
0
1
1
1
0
0
0
0
1
0
1
1
0
0
1
1

7
1
1
0
0
0
0
1
1
1
1
0
1
1
1
0
0
0
0
1
0
1
1
0
0
1

6
1
1
1
0
0
0
0
1
1
1
1
0
1
1
1
0
0
0
0
1
0
1
1
0
0

5
1
1
1
1
0
0
0
0
1
1
1
1
0
1
1
1
0
0
0
0
1
0
1
1
0

4
1
1
1
1
1
0
0
0
0
1
1
1
1
0
1
1
1
0
0
0
0
1
0
1
1

3
1
1
1
1
1
1
0
0
0
0
1
1
1
1
0
1
1
1
0
0
0
0
1
0
1

2
1
1
1
1
1
1
1
0
0
0
0
1
1
1
1
0
1
1
1
0
0
0
0
1
0

1
1
1
1
1
1
1
1
1
0
0
0
0
1
1
1
1
0
1
1
1
0
0
0
0
1

0
1
1
1
1
1
1
1
1
1
0
0
0
0
1
1
1
1
0
1
1
1
0
0
0
0

Table 25: PN9 Whitening Sequence
0x80 ⊕ 0xE1 = 0x61
0xFF ⊕ 0x1D = 0xE2
0x00 ⊕ 0x9A = 0x9A
.
.
.
The complete packet will look like this (assume default preamble, sync word, and CRC configuration):
0xAA, 0xAA, 0xAA, 0xAA, 0x93, 0x0B, 0x51, 0xDE, 0x54, 0x61, 0xE2, 0x9A, 0xF9, 0x9D
8.1.7

Data Byte Swap

If the PKT_CFG2.BYTE_SWAP_EN register field is set than the bits in each byte are swapped,
meaning that bit 0 becomes bit 7, bit 1 becomes bit 6 etc. until bit 7 becomes bit 0.
In TX mode all bytes in the TX FIFO are swapped before optional CRC calculation and whitening are
performed.
In RX mode the data byte is swapped after all the processing is done, meaning that de-whitening and
CRC calculation are done on the original received data, and the swapping is done right before the
actual writing to the RX FIFO. This means that if using address filtering (see Section 8.2.1) is used
when PKT_CFG2.BYTE_SWAP_EN, the user should swap the address manually in the DEV_ADDR
register in order to match the received address due to the fact that the packet engine compares the
address register to the received address before the swapping is done.
Figure 22 shows the data sent over the air vs. the data written to the TX FIFO when byte swap is
enabled (assume that whitening and CRC calculation are disabled). If the receiver uses address
filtering, the address should be programmed to be 0xEA.

SWRU346B

Page 50 of 114

CC120X
Data written to TX FIFO
0x03
0x57
0x26
0xB2
0 0 0 0 0 0 1 1 0 1 0 1 0 1 1 1 0 0 1 0 0 1 1 0 1 0 1 1 0 0 1 0
Data sent on the air
0xC0
0xEA
0x64
0x4D
1 1 0 0 0 0 0 0 1 1 1 0 1 0 1 0 0 1 1 0 0 1 0 0 0 1 0 0 1 1 0 1

Figure 22: Data Byte Swap
8.1.8

UART Mode

If UART mode is enabled (PKT_CFG0.UART_MODE_EN = 1), the packet engine inserts and removes
start/stop bits automatically. In this mode the packet engine will emulate UART back-to-back
transmissions typically done over an asynchronous RF interface, to enable communication with
simple RF devices without packet support.
The start and stop bits are not handled as data, only inserted/removed in the data stream to/from the
modem, hence all packet features are available in this mode. The value of the start/stop bits is
configurable through the PKT_CFG0.UART_SWAP_EN register field.
If whitening is enabled, only the data bits are affected, not the start/stop bits.
A "framing error" occurs in RX mode when the designated "start" and "stop" bits are not received as
expected. As the "start" bit is used to identify the beginning of an incoming byte it acts as a reference
for the remaining bits. If the "start" and "stop" bits are not in their expected value, it means that the
data is not in line and a framing error will occur (the UART_FRAMING_ERROR signal will be asserted).
Framing errors will not stop the on-going reception.

SWRU346B

Page 51 of 114

CC120X
8.2

Packet Filtering in Receive Mode

CC120X supports three different types of packet-filtering; address filtering, maximum length filtering,
and CRC filtering.
8.2.1

Address Filtering

Setting PKT_CFG1.ADDR_CHECK_CFG to any other value than zero enables the address filtering
where the packet handler engine will compare the address field in the packet (see Figure 19) with the
programmed node address in the DEV_ADDR register. If PKT_CFG1.ADDR_CHECK_CFG = 10b it will
in addition check against the 0x00 broadcast address, or both the 0x00 and 0xFF broadcast
addresses when PKT_CFG1.ADDR_CHECK_CFG = 11b. If the received address matches a valid
address, the packet is received and written into the RX FIFO. If the address match fails, the packet is
discarded and the radio controller will either restart RX or go to IDLE dependent on the
RFEND_CFG0.TERM_ON_BAD_PACKET_EN setting (the RFEND_CFG1.RXOFF_MODE setting is
18
ignored ).
8.2.2

Maximum Length Filtering

In variable packet length mode, PKT_CFG0.LENGTH_CONFIG = 01, the PKT_LEN register value is
used to set the maximum allowed packet length. If the received length byte has a larger value than
this, the packet is discarded and the radio controller will either restart RX or go to IDLE dependent on
the RFEND_CFG0.TERM_ON_BAD_PACKET_EN setting (the RFEND_CFG1.RXOFF_MODE setting is
ignored).
8.2.3

CRC Filtering

The
filtering
of
a
packet
when
CRC
check
fails
is
enabled
by
setting
FIFO_CFG.CRC_AUTOFLUSH = 1. The CRC auto flush function will only flush the packet received
with bad CRC, other packets will remain unchanged in the RX FIFO. After auto flushing the faulty
packet, the radio controller will either restart RX or go to IDLE dependent on the
RFEND_CFG0.TERM_ON_BAD_PACKET_EN setting (the RFEND_CFG1.RXOFF_MODE setting is
ignored).
When using the auto flush function, the maximum packet length is 127 bytes in variable packet length
mode and 128 bytes in fixed packet length mode. Note that when PKT_CFG1.APPEND_STATUS is
enabled, the maximum allowed packet length is reduced by two bytes in order to make room in the
RX FIFO for the two status bytes appended at the end of the packet. The MCU must not read from
the current packet until the CRC has been checked as OK.
RX FIFO is
empty
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17

RXLAST

1st packet
CRC OK

2nd packet
CRC OK

3rd packet
CRC Error

4th packet
CRC OK

0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17

RXLAST

RXLAST
CRC Error
RXLAST

.
.
.

124
125
126
127

RXLAST

Figure 23: CRC Autoflush of Faulty Packet
18

RFEND_CFG1.RXOFF_MODE can be changed while in active mode

SWRU346B

Page 52 of 114

CC120X
8.2.4

Auto Acknowledge

By configuring the radio to enter TX after a packet has been received (RFEND_CFG1.RXOFF_MODE =
TX) and enabling termination on bad packets (RFEND_CFG0.TERM_ON_BAD_PACKET_EN = 1)
automatic acknowledgement of packets can be achieved. The Ack. packet should be written to the TX
FIFO before RX mode is being entered. With the settings described above, receiving a bad packet
(error in address, length, or CRC) will have the radio enter IDLE state while receiving a good packet
will cause the radio to enter TX state and transmit the packet residing in the TX FIFO.
8.3

Packet Handling in Transmit Mode

The payload that is to be transmitted must be written into the TX FIFO. The first byte written must be
the length byte when variable packet length is enabled (PKT_CFG0.LENGTH_CONFIG = 1). The
length byte has a value equal to the payload of the packet (including the optional address byte). If
address recognition is enabled in the receiver (PKT_CFG1.ADDR_CHECK_CFG ≠ 0) the second byte
written to the TX FIFO must be the address byte (as the address in not automatically inserted).
If fixed packet length is enabled (PKT_CFG0.LENGTH_CONFIG = 0), the first byte written to the TX
FIFO should be the address (assuming the receiver uses address recognition).
The modulator will first send the programmed number of preamble bytes configured through the
PREAMBLE_CFG1.NUM_PREAMBLE
register
field.
If
data
is
available
in
the
TX FIFO, the modulator will send the sync word (programmed through SYNC_CFG1.SYNC_MODE and
SYNC3/2/1/0) followed by the payload in the TX FIFO. If CRC is enabled
(PKT_CFG1.CRC_CFG ≠ 0), the checksum is calculated over all the data pulled from the TX FIFO,
and the result is sent as two extra bytes following the payload data. If the TX FIFO runs empty before
the complete packet has been transmitted, the radio will enter TX_FIFO_ERR state. The only way to
exit this state is by issuing an SFTX strobe. Writing to the TX FIFO after it has underflowed will not
restart TX mode.
If whitening is enabled, everything following the sync words will be whitened. Whitening is enabled by
setting PKT_CFG1.WHITE_DATA = 1. For more details on whitening, please see Section 8.1.6.
8.4

Packet Handling in Receive Mode

In receive mode, the radio will search for a valid sync word (if SYNC_CFG1.SYNC_MODE ≠ 0) and
when found, the demodulator has obtained both bit and byte synchronization and will receive the first
payload byte. For more details on byte synchronization/sync word detection, please see Section 6.7
If whitening is enabled (PKT_CFG1.WHITE_DATA = 1), the data will be de-whitened at this stage.
When variable packet length mode is enabled (PKT_CFG0.LENGTH_CONFIG = 1), the first byte is
the length byte. The packet handler stores this value as the packet length and receives the number of
bytes indicated by the length byte. If fixed packet length mode is used
(PKT_CFG0.LENGTH_CONFIG = 0), the packet handler will accept the number of bytes programmed
through the PKT_LEN.PACKET_LENGHT register field.
Next, the packet handler optionally checks the address (if PKT_CFG1.ADDR_CHECK_CFG ≠ 0) and
only continues the reception if the address matches. If automatic CRC check is enabled
(PKT_CFG1.CRC_CFG ≠ 0), the packet handler computes CRC and matches it with the appended
CRC checksum.
At the end of the payload, the packet handler will optionally write two extra packet status bytes (see
Table 23 and Table 24) that contain CRC status, LQI, and RSSI value if
PKT_CFG1.APPEND_STATUS = 1.
8.5

Packet Handling in Firmware

When implementing a packet oriented radio protocol in firmware, the MCU needs to know when a
packet has been received/transmitted. Additionally, for packets longer than 128 bytes, the RX FIFO
needs to be read while in RX and the TX FIFO needs to be refilled while in TX. This means that the
MCU needs to know the number of bytes that can be read from or written to the RX FIFO and TX
FIFO respectively. There are two possible solutions to get the necessary status information:

SWRU346B

Page 53 of 114

CC120X
a) Interrupt Driven Solution
The GPIO pins can be used in both RX and TX to give an interrupt when a sync word has been
received/transmitted or when a complete packet has been received/transmitted by setting
IOCFGx.GPIOx_CFG = PKT_SYNC_RXTX (6). In addition, there are four configurations for the
IOCFGx.GPIOx_CFG register that can be used as an interrupt source to provide information on how
many bytes are in the RX FIFO and TX FIFO respectively (see 8.6 for more details).
b) SPI Polling
The GPIO_STATUS register can be polled at a given rate to get information about the current GPIO
values. The NUM_RXBYTES and NUM_TXBYTES registers can be polled at a given rate to get
information about the number of bytes in the RX FIFO and TX FIFO respectively. It is also possible to
use FIFO_NUM_RXBYTES.FIFO_RXBYTES and FIFO_NUM_TXBYTES.FIFO_TXBYTES. These
register fields give the number of bytes available in the RX FIFO and free bytes in the TX FIFO, and
both register values saturates at 15.
8.6

TX FIFO and RX FIFO

The CC120X contains two 128 byte FIFOs, one for received data and one for transmit data. The SPI
interface is used to read from the RX FIFO and write to the TX FIFO. Section 3.2.4 contains details on
the SPI FIFO access. The FIFO controller will detect under/overflow in both the RX FIFO
and the TX FIFO.
A signal will assert when the number of bytes in the FIFO is equal to or higher than a programmable
threshold. This signal can be viewed on the GPIO pins and can be used for interrupt driven FIFO
routines to avoid polling the NUM_RXBYTES and NUM_TXBYTES registers. The IOCFGx.GPIOx_CFG
= RXFIFO_THR (0) and the IOCFGx.GPIOx_CFG = RXFIFO_THR_PKT (1) configurations are
associated with the RX FIFO while the IOCFGx.GPIOx_CFG = TXFIFO_THR (2) and the
IOCFGx.GPIOx_CFG = TXFIFO_THR_PKT (3) configurations are associated with the TX FIFO.
The 7-bit FIFO_CFG.FIFO_THR setting is used to program threshold points. Table 26 lists the
FIFO_THR settings and the corresponding thresholds for the RX and TX FIFO. The threshold value is
coded in opposite directions for the two FIFOs to give equal margin to the overflow and underflow
conditions when the threshold is reached.
FIFO_THR
0
1
2
...
126
127

Bytes in TX FIFO
127
126
125
...
1
0

Bytes in RX FIFO
1
2
3
...
127
128

Table 26: FIFO_THR Settings and the Corresponding FIFO Thresholds
To simplify debug and advanced FIFO features, the full FIFO buffer is memory mapped and can be
accessed directly(see Section 3.2.3). Both FIFO content and FIFO data pointers are accessible. This
can be used to significantly reduce the SPI traffic, see examples below
1. In a hostile RF environment packets are lost and re-transmissions are often required. Normally
the packet data must then be written again over the SPI interface. By using the direct FIFO
access feature and changing the TXFIRST register to point to the head of the previous
message, a re-transmission can be done without writing the packet over the SPI.
2. In many protocols only parts of the message is changed between each transmission (e.g.
changing a read value from a sensor, incrementing a transmission counter). Direct FIFO
access can then be used to change only the new data (the FIFOs are reached through the
0x3E command, see Table 4), leaving the rest of the data unchanged. FIFO data pointers
(TXFIRST and TXLAST) can then be manipulated to re-transmit the packet with changed data.

SWRU346B

Page 54 of 114

CC120X
8.7

IEEE 802.15.4g Support

802.15.4g hardware support is enabled by setting PKT_CFG2.FG_MODE_EN = 1. This will override
all other packet configurations. The only register fields that will be recognized are
PKT_CFG1.CRC_CFG, PKT_CFG1.APPEND_STATUS and PKT_CFG2.BYTE_SWAP_EN. To be
compliant to the 802.15.4g standard PKT_CFG2.BYTE_SWAP_EN must be set to 0.
8.7.1

802.15.4g Packet Format

The format of the 802.15.4g packet format supported by the radio can be seen in Figure 24.
Optional data whitening
Legend:
Inserted automatically in TX,
processed and removed in RX.

PHRA field

PHRB field

Data field

2 x 16 bits

8
bits

8 x n bits

Preamble bits
(Programmable)

8 x 4 bits

CRC-32
or
CRC16

Start Frame
Delimiter

CRC calculation

Unprocessed user data (Except for
whitening)
32 or 16
bits

Figure 24: 802.15.4g Packet Format
PHRA and PHRB in Figure 24 corresponds to PHR[15:8] and PHR[7:0] in the 802.15.4g standard [3]
(see Figure 25 and Figure 26). The radio supports normal 802.15.4g packets (i.e. packets without MS
(Mode Switch)). MS packets must be handled by software.

Bit String Index
Bit Mapping
Field Name

PHRA[7]
PHR[15]
0
MS
Mode switch

PHRA[6:5]
PHR[14:13]
1-2
R1 - R0
Reserved

PHRA[4]
PHR[12]
3
FCS
FCS type

PHRA[3]
PHR[11]
4
DW
Data whitening

PHRA[2:0]: PHRB[7:0]
PHR[10:0]
5 - 15
L10 - L0
Frame length

Figure 25: Format of PHR without Mode Switch

Bit String Index
Bit Mapping
Field Name

PHRA[7]
PHR[15]
0
MS
Mode
switch

PHRA[6:5]
PHR[14:13]
1-2
M1 - M0
Mode switch
parameter
entry

PHRA[4]
PHR[12]
3
FEC
New mode
FEC

PHRA[3:0]: PHRB[7:5]
PHR[11:5]
4 - 10
New mode

PHRB[4:1]
PHR[4:1]
11 - 14
B3 - B0
Checksum

PHRB[0]
PHR[0]
15
PC
Parity
check

Figure 26: Format of PHR with Mode Switch

SWRU346B

Page 55 of 114

CC120X
8.7.2

802.15.4g Packet Control

The radio will support TX and RX with normal 802.15.4g packets (i.e. non Mode Switch packets). All
handling of Mode Switch packets must be entirely done in SW.
8.7.2.1

802.15.4g TX Packets

When transmitting an 802.15.4g packet the format must comply with the format shown in Figure 24. It
is up to the application to write a correct PHR bytes and payload to the TXFIFO. The radio will check
for Mode Switch (MS) and that the frame length is within the specifications before transmitting the
packet. If MS is not set and the frame length complies with the standard the radio will check the Data
Whitening (DW) bit field and the Frame Check Sequence (FCS) bit field and apply whitening and FCS
according to the bit fields. The transmission flow is outlined in Figure 27.

802.15.4g mode and STX

ModeSwitch(MS)?
No

Yes

Framelength
valid ?

Send packet
without
CRC16/CRC32

Yes

Send packet with
CRC16/CRC32

Abort transmission
No error code

Assert done

Figure 27: Transmission Flow in 802.15.4g Mode

SWRU346B

Page 56 of 114

CC120X
8.7.2.2

802.15.4g RX Packets

The radio supports reception of normal (non Mode Switch) 802.15.4g packets. If the MS bit is not set
and the frame length is valid, the radio will receive the rest of the payload according to the PHR
configuration. If a Mode Switch packet is received or the frame length field is not valid, the radio will
abort RX and the Mode Switch frame (PHR bytes) will be available in the RXFIFO. RSSI for Mode
Switch packets is not available. Figure 28 outlines the reception flow for an 802.15.4g packet.

802.15.4g mode and SRX

Receive PHR

ModeSwitch(MS)
or
Illegal framelength?

Yes

Abort reception
assert pkt_length_failed

Continue PHR-configured
reception

Assert done with appropiate status

Successful
reception
Yes

SW(abstraction routine)
Marc_status=0x80

Yes
Successful 15.4g
packet

Successful
15.4g MS
packet

(MS should be performed in parallell)

MS part of
system?

SW: Run BCH(15,11)
and parity check on
PHR to check for
MS-packet

Yes

MS packet

15.4g packet has
failed

Return to MAC layer

Figure 28: 802.15.4g Packet Reception

SWRU346B

Page 57 of 114

CC120X
8.7.3

802.15.4g Append Status

If the PKT_CFG1.APPEND_STATUS bit is set, two status bytes containing information on CRC, LQI
and RSSI will be written to the RXFIFO.

Bit
7:0

Field Name
RSSI

Description
RSSI value

Table 27. Received Packet Status Byte 1
(first byte appended after the data)

Bit
7

Field Name
CRC_OK

6:0

LQI

Description
1: CRC32 OK if FCS type = 0 and CRC32 is OK
1: CRC16 OK if FCS type = 1 and CRC16 is OK
0: CRC error in received data
Indicating the link quality

Table 28: Received Packet Status Byte 2
(second byte appended after the data)
8.7.4

802.15.4g Data Byte - Bit Swapping

If the PKT_CFG1.BYTE_SWAP_EN register field is set than the bits in each byte are swapped,
meaning that bit 0 become 7, bit 1 become bit 6 etc. until bit 7 becomes bit 0.
In TX mode all bytes in the TX FIFO are swapped before optional CRC calculation and whitening are
performed.
In RX mode the data byte is swapped after all the processing is done, meaning that de-whitening and
CRC calculation are done on the original received data, and the swapping is done right before the
actual writing to the RX FIFO.
Bit swapping should be turned off to be compliant with the 802.15.4g standard.
8.7.5

802.15.4g Data Whitening

Data whitening of the payload is defined by the Data Whitening field (DW) in the PHR. If this bit is set
all data except the preamble, SFD and PHR field will be XOR-ed with a 9-bit pseudo-random (PN9)
sequence before being transmitted. At the receiver the DV bit of the PHR is read and the data is
XOR-ed with the same pseudo-random sequence to de-white the data back to its original form.
The PN9 generator is defined as seen in Figure 29. The seed in the PN9 generator is set to all 1’s
and is reinitialized after each packet.

PN9

Figure 29: PN9 Generator

SWRU346B

Page 58 of 114

CC120X
8.8

802.15.4g Frame Check Sequence (FCS)

The radio supports both a 16-bit CRC and a 32-bit CRC for the Frame Check Sequence (FCS). The
type to be used is defined by the FCS field in the PHR bytes. The length of the FCS must be added to
Frame Length of the PHR in order to have a valid 802.15.4g packet. It is the applications
responsibility that PHR fields are correct. Table 29 shows the relationship between the FCS Type field
and the transmitted CRC bytes.
FCS Type Field Value
0
1

Transmitted FCS Length
4 byte
2 byte

Table 29: Transmitted FCS Length
8.8.1

802.15.4g Forward Error Correction (FEC)

A Non Recursive and Non Systematic Code (NRNSC) encoder is implemented to support FEC for
802.15.4g. FEC is optional for 802.15.4g and is indicated by the synchronization word used for the
packet.
In addition to set PKT_CFG2.FG_MODE_EN = 1, the following register fields must be set to enable
802.15.4g FEC support:
PKT_CFG1.FEC_EN = 1
SYNC_CFG1.SYNC_MODE = 7 (DualSync Search)
When receiving an 802.15.4g packet the receiver will check the sync word received and if it matches
the sync word contained in the two high bytes fields in the sync word registers (SYNC3 and SYNC2) it
will assume that the packet is FEC encoded.
When transmitting a FEC encoded 802.15.4g packet it is important to have the FEC defined sync
word written to the SYNC1 and SYNC0 register field as the CC120X will always send the sync word
contained in the lower end of the sync word registers when SYNC_CFG1.SYNC_MODE = 7.
8.9

Transparent and Synchronous Serial Operation

Several features and modes of operation have been included in the CC120X to provide backward
compatibility with legacy systems that cannot be supported by the built in packet handling
functionality. For new systems, it is recommended to use the built-in packet handling features, as they
give more robust communication, significantly offload the microcontroller, and simplify software
development. There are two serial modes and they are described in the two following sections.
Serial mode is only supported for 2’ary modulations. The exception in synchronous serial mode (RX)
which also supports 4’ary modulation formats. Figure 30 shows SERIAL_CLK and SERIAL_RX for the
data 0xAA for both 2-FSK and 4-FSK. The symbol rate is the same in both cases.

2-FSK
SERIAL_RX
SERIAL_CLK

1 0

1 0
t

1 0

4-FSK

1
2t

SERIAL_RX
SERIAL_CLK

1 0

Time

Figure 30: 2’ary vs. 4’ary Modulation Format in Serial Mode

SWRU346B

Page 59 of 114

CC120X
8.9.1

Synchronous Serial Mode

In the synchronous serial mode, data is transferred on a two-wire serial interface. The CC120X
provides a clock (IOCFGx.GPIOx_CFG = SERIAL_CLK (8)) that is used to set up new data on the
data input line or sample data on the data output line. Data timing recovery is done automatically. The
data pin is updated on the falling edge of the clock pin at the programmed symbol rate. Sync word
insertion/detection may or may not be active, depending on the sync mode. If sync word detection is
enabled (SYNC_CFG1.SYNC_MODE ≠ 0) the serial clock (SERIAL_CLK) will not be output on the
GPIO before a sync word is transmitted/received. When SYNC_MODE = 0 (blind mode) it is
recommended to transmit a minimum of 4 bytes preamble.
Define a GPIO pin to be serial data clock for both TX and RX operation. For RX operation, another
GPIO pin has to be defined as serial data output (IOCFGx.GPIOx_CFG = SERIAL_RX (9)).
For TX operation, the GPIO0 pin is explicitly used as serial data input. This is automatically done
when in TX. In order to avoid internal I/O conflict, GPIO0 should be defined as tri-state. GPIO0 will be
automatically tri-stated in TX if the GPIO0 is defined as serial clock or serial data output
(IOCFG0.GPIO0_CFG = 8 or 9). If this is not the case, GPIO0 must be manually tri-stated by
setting IOCFG0.GPIO0_CFG = HIGHZ (48).
In synchronous serial mode the TX data must be set up on the falling edge of the data clock output
from CC120X.
In addition to set PKT_CFG2.PKT_FORMAT = 1, the following register fields must be set:
MDMCFG1.FIFO_EN = 0
MDMCFG0.TRANSPARENT_MODE_EN = 0
IOCFGx.GPIOx_CFG = 001001b (SERIAL_RX. Only necessary for RX mode)
IOCFGx.GPIOx_CFG = 001000b (SERIAL_CLK)
19

SERIAL_STATUS.IOC_SYNC_PINS_EN = 1 (Only necessary for TX mode )
PREAMBLE_CFG1.NUM_PREAMBLE = 0
Synchronous serial mode is often used in applications needing to be backward compatible, and sync
detection is disabled (SYNC_CFG1.SYNC_MODE = 0) since the format of the sync word often do not
match the supported sync word format. Best radio performance is however achieved when
SYNC_MODE ≠ 0. In cases where the packet has a preamble but not a sync word that matches the
sync format supported by the CC120X, the radio can simply use the preamble as a sync word.
Consider the case where a receiver wants to receive packets with 3 different addresses but no
common sync word:
Packet 1: 0xAA, 0xAA, 0xAA, 0xAA, Address1, Data0, Data 1, Data 2, …
Packet 1: 0xAA, 0xAA, 0xAA, 0xAA, Address2, Data0, Data 1, Data 2, …
Packet 1: 0xAA, 0xAA, 0xAA, 0xAA, Address3, Data0, Data 1, Data 2, …
By setting SYNC_CFG1.SYNC_MODE = 010b and SYNC1 = SYNC0 = 0xAA a sync word is detected
somewhere within the preamble and the serial clock will be output on a GPIO when SYNC_EVENT is
asserted. Now the MCU can manually start searching for the 3 different addresses. When this method
is used TOC_CFG.TOC_LIMIT should be 0. In blind mode, TOC_LIMIT must be 1 or 11b.

If this bit is set in RX mode, GPIO2 must be hardwired to 0 (IOCFG2.GPIO2_CFG = HW0 (51))

SWRU346B

Page 60 of 114

CC120X
8.9.2

Transparent Serial Mode

CC120X does not do any timing recovery and just outputs the hard limited baseband signal. In
transparent serial mode the symbol rate programming does not affect operation. When transparent
mode is enabled, the device is set up to resemble a legacy purely analog front end device with
baseband output to support legacy pulse position modulation, PWM modulated signals etc. In
transparent mode the signal is digitally demodulated and output on GPIO pins through a
programmable interpolation filter (MDMCFG0.TRANSPARENT_INTFACT). The interpolation filter is used
to eliminate jitter on the baseband signal. This is useful when using external DSP demodulators as
jitter introduce noise in the demodulation process. The rate on the GPIO is ((4 x receiver bandwidth) x
interpolation factor).
When using transparent serial mode make sure the interfacing MCU/DSP does proper oversampling.
In transparent serial mode, several of the support mechanisms for the MCU that are included in
CC120X will be disabled, such as packet handling hardware, buffering in the FIFO, and so on.
Preamble and sync word insertion/detection is not supported in transparent serial mode.
For TX operation, the GPIO0 pin is explicitly used as serial data input. This is automatically done
when in TX. In order to avoid internal I/O conflict, GPIO0 should be defined as tri-state. GPIO0 will be
automatically tri-stated in TX if the GPIO0 is defined as serial clock or serial data output
(IOCFG0.GPIO0_CFG = 8 or 9). If this is not the case, GPIO0 must be manually tri-stated by
setting IOCFG0.GPIO0_CFG = HIGHZ (48).
Data output can be observed on GPIO0/1/2/3. This is set by the IOCFGx.GPIOx_CFG fields.
In addition to set PKT_CFG2.PKT_FORMAT = 11b, the following register fields must be set:
MDMCFG1.FIFO_EN = 0
MDMCFG0.TRANSPARENT_MODE_EN = 1
IOCFGx.GPIOx_CFG = 001001b (SERIAL_RX. Only necessary for RX mode)
SERIAL_STATUS.IOC_SYNC_PINS_EN = 1 (Only necessary for TX mode)
In transparent mode, the frequency offset correction is calculated based on the incoming samples
clocked with a rate equal to 2·RX filter BW. If the data stream contains a row of equal symbols the
correction factor will move too far to one side with reduced sensitivity as a result. For systems where it
is not possible to have a white data stream the following may be done to improve sensitivity:
Set FREQOFF_CFG.FOC_KI_FACTOR = 3 to select the slowest loop
For a system where the frequency error is less than the deviation the frequency offset
correction may be turned off by setting FREQOFF_CFG.FOC_EN = 0

SWRU346B

Page 61 of 114

CC120X
9

Radio Control

CC120X has a built-in state machine that is used to switch between different operational states
(modes). The change of state is done either by using command strobes or by internal events such as
TX FIFO underflow. A simplified state diagram is shown in Figure 2. The numbers refer to the state
numbers readable from the MARCSTATE.MARC_STATE register field.
9.1

Power-On Start-Up Sequence

When the power supply is turned on, the system must be reset. This is achieved by one of the two
sequences described below, i.e. automatic power-on reset (POR) or manual reset.
9.1.1

Automatic POR

A power-on reset circuit is included in the CC120X. The internal power-up sequence is completed when
CHIP_RDYn goes low. CHIP_RDYn is observed on the SO pin after CSn is pulled low (See Section
3.1.2 for more details).
When the CC120X reset is completed, the chip will be in the IDLE state and the crystal oscillator will be
running. If the chip has had sufficient time for the crystal oscillator to stabilize after the power-onreset, the SO pin will go low immediately after taking CSn low. If CSn is taken low before reset is
completed, the SO pin will first go high, indicating that the crystal oscillator is not stabilized, before
going low as shown in Figure 31.
CSn

SO
XOSC Stable

Figure 31: Power-On Reset
9.1.2

Manual Reset

The other reset possibilities on the CC120X are issuing using the SRES command strobe or using the
RESET_N pin. By issuing a manual reset, all internal registers are set to their default values and the
radio will enter IDLE state.
9.2

Crystal Control

The crystal oscillator (XOSC) is either automatically controlled or always on, if
XOSC2.XOSC_CORE_PD_OVERRIDE = 1. If the XOSC is forced on, the crystal will always stay on
even if an SXOFF, SPWD, or SWOR command strobe has been issued. This can be used to enable fast
start-up from SLEEP/XOFF at the expense of a higher current consumption. If
XOSC2.XOSC_CORE_PD_OVERRIDE = 0, the XOSC will be turned off if the SXOFF, SPWD, or SWOR
command strobes are issued; the state machine then goes to XOFF or SLEEP state. This can only be
done from the IDLE state. The XOSC will be automatically turned on again when CSn goes low, and
the radio will enter IDLE state. The SO pin on the SPI interface must be pulled low before the SPI
interface is ready to be used, as described in Section 3.1.2.
Crystal oscillator start-up time depends on crystal ESR and load capacitances.
9.3

Voltage Regulator Control

The voltage regulator to the digital core is controlled by the radio controller. When the chip enters the
SLEEP state which is the state with the lowest current consumption, the voltage regulator is disabled.
This occurs after CSn is released when a SPWD or SWOR command strobe has been sent on the SPI
interface. The chip is then in the SLEEP state. Setting CSn low again will turn on the regulator and
crystal oscillator and make the chip enter the IDLE state.

SWRU346B

Page 62 of 114

CC120X
9.4

Active Modes

CC120X has two active modes: receive (RX) and transmit (TX). These modes are activated directly by
the MCU by using the SRX and STX command strobes, or automatically by eWOR (RX mode).
The MCU can manually change the state from RX to TX and vice versa by using the command
strobes. If the radio controller is currently in transmit and the SRX strobe is used, the current
transmission will be ended and the transition to RX will be done. If the radio controller is in RX when
the STX or SFSTXON command strobes are used, the TX-on-CCA function will be used. If the channel
is clear, TX (or FSTXON state) is entered. The PKT_CFG2.CCA_MODE setting controls the conditions
for clear channel assessment (see Section 6.11 for more details).
The SIDLE command strobe can always be used to force the radio controller to go to the IDLE state.
9.4.1

When RX is activated, the chip will remain in receive mode until:
A packet is received
20

An SIDLE, SRX , STX, or SFSTXON command strobe is being issued
The RX FIFO overflows/underflows
The RX termination timer expires
A CS or PQT based termination takes place
When a packet is successfully received, the radio controller goes to the state indicated by the
RFEND_CFG1.RXOFF_MODE setting, i.e. IDLE, FSTXON, TX or RX. When a bad packet is received
(packet length/address/CRC error) the radio controller will either restart RX or go to IDLE depending
on the RFEND_CFG0.TERM_ON_BAD_PACKET_EN setting.
When an RX FIFO overflow or underflow occurs, the radio will enter RX_FIFO_ERR state. When RX
terminates due to the RX termination timer or lack of CS/PQT, the radio will enter IDLE mode (via
CALIBRATE depending on the SETTLING_CFG.FS_AUTOCAL setting).
Please see Section 9.6 for details on which states the radio enters after RX when eWOR is used.
9.4.2

Similarly, when TX is active the chip will remain in the TX state until:
The current packet has been transmitted
An SIDLE or SRX command strobe is being issued
The TX FIFO overflows/underflows
When a packet is successfully transmitted, the radio controller goes to the state indicated by the
RFEND_CFG0.TXOFF_MODE setting. The possible destinations are the same as for RX.

When an SRX strobe is issued in RX state, RX is restarted (the modulator starts searching for a
sync word). If the radio was in the middle of a packet reception, part of the “old” packet will remain in
the RX FIFO so NUM_RXBYTES or RX_LAST should be read before strobing SRX to keep track of
where the old and new packets are located in the RX FIFO.

SWRU346B

Page 63 of 114

CC120X
9.5

RX Termination

RX can be terminated by the use of an RX termination timer or based on the assertion of
CARRIER_SENSE and/or PQT_REACHED. When RX terminates, the chip will always go back to IDLE if
eWOR is disabled and back to SLEEP (via IDLE) if eWOR is enabled.
9.5.1

RX Termination Timer

CC120X has functionality to allow for automatic termination of RX after a programmable timeout. The
main use for this functionality is in eWOR mode, but it is also useful for other applications as it
reduces the need for a dedicated MCU timer. The termination timer starts when the chip has entered
RX state, and the timeout is programmable with the RFEND_CFG1.RX_TIME setting. When the timer
expires, the radio controller will check the condition for staying in RX.
The programmable conditions are:
RFEND_CFG1.RX_TIME_QUAL = 0: Continue receive if sync word has been found
RFEND_CFG1.RX_TIME_QUAL = 1: Continue receive if sync word has been found, or if PQT
is reached or CS is asserted
Equation 22 can be used to calculate the RX timeout.

RX Timeout

EVENT 0
2 RX _ TIME 3

MAX 1, FLOOR

24 WOR _ RES

1250
[s]
f XOSC

Equation 22: RX Timeout
EVENT0 is programmed through WOR_EVENT0_MSB and WOR_EVENT0_LSB, RX_TIME is found in
RFEND_CFG1 and WOR_RES in WOR_CFG1.
Figure 32 shows how the radio stays in RX until a packet has been received since a sync word was
found before the RX termination timer expired (after 10 ms).
RX_TIME_QUAL = 0
No sync found after 10 ms

IDLE

IDLE
Time [ms]

RX_TIME_QUAL = 0
Sync found within 10 ms
Preamble
IDLE

Sync

Payload

CRC
IDLE

Time [ms]
1

Figure 32: RX Termination when RX_TIME_QUAL = 0 (RX Timeout = 10 ms)

SWRU346B

Page 64 of 114

CC120X
Figure 33 shows how the radio behaves when RX_TIME_QUAL = 1 (assume that
RFEND_CFG0.ANT_DIV_RX_TERM_CFG = 0). When the RX termination timer expires, the radio will
check if a sync word is found or if CARRIER_SENSE or PQT_REACHED has been asserted (to check on
PQT_REACHED, PREAMBLE_CFG0.PQT_EN should be set). If this is the case the radio will remain in
RX until a packet has been received. This is the case even if the condition for staying in RX is no
longer true. As shown in the figure, the radio remains in RX after the 10 ms timeout even if a
preamble is no longer present (PQT_REACHED will be de-asserted) as it only checks the condition for
staying in RX once when the termination timer expires. The radio will not exit RX mode until a packet
has been received.
RX_TIME_QUAL = 1

No sync found after 10 ms
IDLE

IDLE
Time [ms]

RX_TIME_QUAL = 1

Preamble

Sync

Payload

CRC
Preamble found within 10 ms

IDLE

Time [ms]
1

RX_TIME_QUAL = 1
Preamble found within 10 ms

Preamble
IDLE

Preamble

Sync

Payload

CRC
IDLE

Time [ms]
1

Figure 33: RX Termination when RX_TIME_QUAL = 1 (RX Timeout = 10 ms)

SWRU346B

Page 65 of 114

CC120X
9.5.2

RX Termination Based on CS

If RFEND_CFG0.ANT_DIV_RX_TERM_CFG = 1 the device will use the first RSSI sample to
determine if a carrier is present in the channel. If no carrier is present (CARRIER_SENSE not
asserted), RX will terminate. The RSSI samples are continually evaluated, and if the RSSI level falls
below the threshold (programmed through the AGC_CS_THR register) RX will terminate if not sync is
found. This can be used to achieve very low power by reducing the time in RX mode to a minimum.
Figure 34 shows how RX mode will be terminated based on CS for different scenarios. Note that sync
detection will keep the radio in RX until the packet is received regardless of the state of the
CARRIER_SENSE signal.
RX_TIME_QUAL = 0
RFEND_CFG0.ANT_DIV_RX_TERM_CFG = 001b
RX terminated due to lack of carrier

RX
IDLE

IDLE

AGC_CARRIER_SENSE
Time [ms]
1

RX_TIME_QUAL = 0
RFEND_CFG0.ANT_DIV_RX_TERM_CFG = 001b

IDLE

RX terminated when carrier is no
longer present

IDLE

AGC_CARRIER_SENSE
Time [ms]
1

RX_TIME_QUAL = 0
RFEND_CFG0.ANT_DIV_RX_TERM_CFG = 001b
RX terminated at RX timeout due to
no sync word found
(RX_TIME_QUAL = 0)
IDLE

IDLE

CARRIER_SENSE
Time [ms]
1

RX_TIME_QUAL = 1

RX terminated when carrier is no
longer present (not terminated at RX
timeout since carrier is present at
that time and RX_TIME_QUAL = 1)

RFEND_CFG0.ANT_DIV_RX_TERM_CFG = 001b

IDLE

CARRIER_SENSE
Time [ms]
1

Figure 34: RX Termination Based on CS (RX Timeout = 10 ms)
RX termination based on CS can be used even if the RX termination timer is not used
(RFEND_CFG1.RX_TIME = 111b).
9.5.3

RX Termination Based on PQT

If RFEND_CFG0.ANT_DIV_RX_TERM_CFG = 100b the device will use the PQT indication to
determine if RX mode should be terminated or not. If no preamble is detected, RX will be terminated.
The PQT indication is continually evaluated, and if the PQT level falls below the threshold RX will
terminate if no sync is found. This can be used to achieve very low power by reducing the time in RX
mode to a minimum.
RX termination based on PQT can be used even if the RX termination timer is not used
(RFEND_CFG1.RX_TIME = 111b).

SWRU346B

Page 66 of 114

CC120X
9.6

Enhanced Wake on Radio (eWOR)

The optional enhanced Wake on Radio (eWOR) functionality enables CC120X to periodically wake up
from SLEEP and listen for incoming packets without MCU interaction.
When the SWOR strobe command is sent on the SPI interface, the CC120X will go to the SLEEP state
when CSn is released. Unless an external crystal is used (EXT_CTRL.EXT_40K_CLOCK_EN = 1)
the RC oscillator must be enabled by setting WOR_CFG0.RC_PD = 0 before the SWOR strobe is
issued, as it is the clock source for the eWOR timer (see Section 9.9 for more info on the RC
oscillator). The on-chip eWOR timer will set CC120X into IDLE state and then RX state. After a
programmable time in RX (see Section 9.5.1), the chip will go back to the SLEEP state, unless a
packet is received.
To exit eWOR mode, CSn must be pulled low.
The on-chip eWOR timer will be clocked, independently of eWOR mode, whenever the RC oscillator
is running. This preserves the timing when exiting eWOR mode. The on-chip eWOR timer can be
reset to the Event 1 value by issuing the SWORRST strobe command. The value of the eWOR timer is
available through WOR_TIME1 and WOR_TIME0.
Every time a sync word is found, the current value of the eWOR timer will be captured and it can be
read through the WOR_CAPTURE1 and WOR_CAPTURE0 registers. This feature is useful in applications
where re-synchronization of the eWOR timer is required.

CC120X can be configured to signal the MCU that a packet has been received by using a GPIO pin.
When the MCU has read the packet, it can put the chip back into SLEEP with the SWOR strobe from
the IDLE state.
9.6.1

WOR EVENT 0, 1, and 2

The eWOR timer has three events, Event 0, Event 1, and Event 2. In the SLEEP state with eWOR
activated, reaching Event 0 will turn on the digital regulator and start the crystal oscillator (unless
WOR_CFG1.WOR_MODE = 100b). Event 1 follows Event 0 after a programmed timeout (tEvent1).
Figure 35 shows the timing relationship between Event 0 timeout and Event 1 timeout.
Rx Timeout
State:

SLEEP

IDLE

Event0

Event1

SLEEP

IDLE

Event0

Event1
t

tEvent0
tEvent0
tEvent1

tEvent1
tSLEEP

Figure 35: Event 0 and Event 1 Relationship
The time between two consecutive Event 0’s is programmed with a mantissa value given by
WOR_EVENT0_MSB and WOR_EVENT0_LSB and an exponent value set by WOR_CFG1.WOR_RES. tEvent0
is given by Equation 23.

t Event 0

1
f RCOSC

EVENT 0 25 WOR _ RES [s]

Equation 23: tEvent0
The Event 1 timeout is programmed with a mantissa value decoded by the WOR_CFG1.EVENT1
setting.

SWRU346B

Page 67 of 114

CC120X
WOR_CFG1.EVENT1

WOR_EVENT1
4
6
8
12
16
24
32
48

000
001
010
011
100
101
110
111

tEvent1 [µs] (fRCOSC = 40 kHz)
100
150
200
300
400
600
800
1200

Table 30: Event 1
Equation 24 gives the Event 1 timeout.

t Event 1

1
f RCOSC

WOR _ EVENT1[s]

Equation 24: tEvent1
An SRX strobe is issued on Event 1 if tEvent1 is larger than the crystal start-up time. If tEvent1 is shorter
than the crystal start-up time (CHIP_RDYn not asserted when Event 1 occurs), the SRX strobe will be
issued as soon as CHIP_RDYn is asserted.
Event 2 can used to autonomously take the system out of SLEEP at regular intervals to perform RC
oscillator calibration. This will improve the accuracy of the timer.
The Event 2 timing is programmed with an exponent value decoded by the WOR_CFG0.EVENT2_CFG
setting.
WOR_CFG0.EVENT2_CFG
00
01
10
11

WOR_EVENT2
Disabled
15
18
21

tEvent2 [s] (fRCOSC = 40 kHz)
~0.82
~6.55
~52.4

Table 31: WOR_EVENT2
tEvent2 is given by Equation 25.

t Event 2

2WOR _ EVENT 2
[s]
f RCOSC

Equation 25: tEvent2
When setting EVENT2_CFG ≠ 0, tEvent0 must be greater than tEvent2 and RC oscillator calibration must
be enabled (WOR_CFG0.RC_MODE = 10b).
21

All three events can be monitored on the GPIO pins by setting IOCFGx.GPIOx_CFG
WOR_EVENT0/1/2 (54/55/56).

If IOCFGx.GPIOx_CFG = WOR_EVENT2 (56), WOR_CFG0.EVENT2_CFG must be ≠ 0
SWRU346B

Page 68 of 114

CC120X
9.6.2

eWOR Modes

The different eWOR modes are programmed through the WOR_CFG1.WOR_MODE register field. The
three most common eWOR modes are Feedback Mode, Normal Mode, and Legacy Mode.
Feedback Mode
The radio wakes up on Event 0 and strobes SRX on Event 1. If a good packet is being received
the radio enters the state indicated by the RFEND_CFG1.RXOFF_MODE setting. When a bad
packet is received (packet length/address/CRC error) the radio will either restart RX or enter
SLEEP
mode,
depending
on
RFEND_CFG0.TERM_ON_BAD_PACKET_EN.
If
TERM_ON_BAD_PACKET_EN = 1, the radio will go to IDLE instead of SLEEP after receiving 16
22
bad packets in a row . When this occurs, a GPIO pin can be used to wake up the MCU by
setting IOCFGx.GPIOx_CFG = MCU_WAKEUP (20). Please see Section 3.4.1.2 for more
details on MCU Wake-Up.
Normal Mode
This mode is equivalent to Feedback Mode without the bad packet counter feature. This means
that the radio can go back to SLEEP when a bad packet is received as long as
TERM_ON_BAD_PACKET_EN = 1, but it does not give any feedback to the MCU regarding this.
Legacy Mode
As long as a sync word has been received, the radio will not go back to SLEEP automatically. If
a good packet is being received the radio enters the state indicated by the
RFEND_CFG1.RXOFF_MODE setting and when a bad packet is received it will either restart RX
or enter IDLE mode, depending on RFEND_CFG0.TERM_ON_BAD_PACKET_EN.
There are also two other modes using the eWOR timer as a general sleep timer or to generate timing
signals for the MCU.
Event 1 Mask Mode enables the radio to wake up from SLEEP on Event 0 without going to RX mode
while Event 0 Mask Mode keeps the radio in SLEEP mode ignoring all the events. In both cases the
WOR_EVENT0/1 signals can still be made available on the GPIO pins to be used by the MCU or other
peripherals in the system by setting IOCFGx.GPIOx_CFG = WOR_EVENT0/1 (55/56).
9.6.3

eWOR Usage

eWOR can be used in systems where a transmitter sends a packet at a given interval (see Figure 36).
Preamble + sync
Payload

1s
XOSC Start-Up
RX Timeout
Extra time in RX
to receive the packet

1s
RX

Time

1s
RX

Time

Figure 36: eWOR Mode (RX and TX in sync.)
Under ideal circumstances, the receiver and transmitter is in sync as shown in Figure 36, but in most
cases this is not the case. Assume the transmitter is sending packets at a slower rate than the
receiver wakes up to look for packet as shown in Figure 37.

To not receive a packet at all is in this content equivalent to receiving a bad packet
SWRU346B

Page 69 of 114

CC120X
Preamble + sync
Payload

1.x s
XOSC Start-Up
RX Timeout
Extra time in RX
to receive the packet

1.x s
RX

Time

1.x s
RX

Time

Figure 37: eWOR Mode (RX and TX out of sync.)
In this case, the WOR_CAPTURE1 and WOR_CAPTURE0 registers on the receivers would show a higher
and higher value for every packet received, indicating that the transmitter is sending at a slower rate
than tEVENT0. The receiver should therefore increase t EVENT0 to stay in sync with the transmitter (see
Figure 38).
Preamble + sync
Payload

1.x s
XOSC Start-Up
RX Timeout
Extra time in RX
to receive the packet

1.x s
RX

1.x s

Time

1.x s
RX

1.x s

Figure 38: eWOR Mode (RX and TX re-synchronized)
9.7

RX Sniff Mode

For battery operated systems the RX current is an important parameter and to increase battery
lifetime a novel RX Sniff Mode feature has been designed for the CC120X family to autonomously sniff
for RF activity using an ultra-low-power algorithm. RX Sniff Mode can either be enabled by using
eWOR together with RX termination based on CS (see 9.5.2) or PQT (see 9.5.3) or by using the RX
duty cycle timer (see Section 9.8 for more details).
The CC120X platform is designed for extremely fast settling time hence the receiver can be turned on
and off quickly. Together with the ability to quickly and reliably detect if there is RF activity or not this
is a key parameter to reduce the power consumption.
The CC120X family use strong DSP logic to detect a sync word and the preamble is only needed for
AGC settling, i.e. settling the gain of the front end. A 4 bits preamble is enough for settling including
frequency offset compensation (AFC).

SWRU346B

Page 70 of 114

CC120X
9.7.1

RX Sniff Mode Usage

RX Sniff Mode is extremely useful in cases where you do not know when the transmitter is going to
send a packet. Figure 39 shows ordinary RX mode, where the radio must stay continuously in RX to
make sure that it will receive the transmitted packet.
TX
4 bits
preamble

Sync

Payload

Time

Figure 39: Ordinary RX Mode
By increasing the preamble of the transmitted packet, the receiver can implement RX Sniff Mode and
wake up at an interval that ensures that at least 4 bits of preamble is received. RX termination based
on CS greatly reduces the time in RX and forces the radio back in SLEEP if there is no signal on the
air.
TX
Preamble
(4 bytes)

R
X

Sync

Payload

R
X

Time

Figure 40: RX Sniff Mode
The wake-up interval (tEvent0) can be increased further by letting the receiver look for an 11 bits sync
word (16 bits are sent on the air). This way, the 5 MSBs can be used for AGC settling and no
preamble is needed (see Figure 41).
TX
Preamble
(4 bytes)

R
X

Sync

Payload

Time

Figure 41: RX Sniff Mode (no preamble)

SWRU346B

Page 71 of 114

CC120X
9.8

RX Duty Cycle Mode

In systems with high symbol rate and/or very short preamble one should use the RX duty cycle timer
instead of the eWOR timer to implement RX Sniff Mode, as the RX duty cycle timer provides smaller
timeouts/gives finer resolution on the time not spent in RX. The radio should still be configured to use
RX termination based on CS or PQT.
When the RX duty cycle timer is used (WOR_CFG0.RX_DUTY_CYCLE_MODE ≠ 0), the radio will enter
RXDCM state instead of SLEEP state when the radio is not in RX. Table 32 lists the different RX duty
cycle modes and the RX modules enabled when the radio is in RXDCM state. Figure 42 shows the
different states the radio will enter when RX duty cycle mode is used.
RX_DUTY_CYCLE_MODE
0
1

Mode
RXDCM Off
RXDCM0

RXDCM1

RXDCM2

RX Modules Enabled while in RXDCM State
RXDCM state not reachable
Digital RX modules turned off. Analog RX modules enabled. Next state is RX.
This is the mode that provides lowest current reduction
All modules in the FS_LOCK state. Next state is IFADCON. This is the mode that
provides medium current reduction
All modules in IDLE state. Next state is BIAS_SETTLE. This is the state the
provides the highest current reduction

Table 32: RX Duty Cycle Mode
The time spent in RXDCM (tRXDCM) state is controlled via the RXDCM_TIME.RX_DUTY_CYCLE_TIME
23
and WOR_CFG1.WOR_RES register fields and can be calculated using Equation 26 .

RX _ DUTY _ CYCLE _ TIME 2WOR _ RES [ s]

t RXDCM

Equation 26: tRXDCM
RX duty cycle mode must not be used together with eWOR mode or antenna diversity. To enter
RXDCM, an SRX strobe should be issued when WOR_CFG0.RX_DUTY_CYCLE_MODE ≠ 0.

IDLE

SFRX

BIAS_SETTLE
REG_SETTLE

RX_DUTY_CYCLE_MODE = 11b
& duty_cycle done

RXOFF_MODE = 0
| RX timeout

RX_FIFO_ERROR

FS_AUTOCAL = 01b
& SRX

SRX
STARTCAL

RXDCM
CAL_COMPLETE
RXFIFO_
UNDER/OVERFLOW

BWBOOST
FS_LOCK
IFADCON

RX_DUTY_CYCLE_MODE = 10b
& duty_cycle done

rx_duty_cycle &
(CS/PQT termination
| RX timeout)

SRX
RX_DUTY_CYCLE_MODE = 01b
& duty_cycle done

RXOFF_MODE = 11b
| packet failed

Done | RXFIFO_
OVERFLOW |
packet failed |
RX timeout

RX_END

Figure 42: RXDCM State Diagram
23

For RX_DUTY_CYCLE_MODE = 0, t RXDCM

2WOR _ RES [µs]

SWRU346B

Page 72 of 114

CC120X
9.9

RC Oscillator Calibration

The frequency of the low-power RC oscillator used for the eWOR functionality varies with temperature
and supply voltage. In order to keep the frequency as accurate as possible, the RC oscillator should
be calibrated whenever possible. Two automatic RC calibration options are available that are
controlled by the WOR_CFG0.RC_MODE setting:
RC calibration is enabled when the XOSC is running
RC calibration is enabled on every 4th time the device is powered up and goes from IDLE to
RX (should only be used together with eWOR).
During calibration the eWOR timer will be clocked on a down-divided version of the XOSC clock.
When the chip goes to the SLEEP state, the RC oscillator will use the last valid calibration result. The
frequency of the RC oscillator is calibrated to the main crystal frequency divided by 1000 (40 kHz).
In applications where the radio wakes up very often, typically several times every second, it is
possible to do the RC oscillator calibration once and then turn off calibration to reduce the current
consumption. If the RC oscillator calibration is turned off, it will have to be manually turned on again to
resume calibration. This will be necessary if temperature and supply voltage changes to maintain
accuracy.
When the WOR_CFG0.RC_MODE setting is altered from 0 or 1 to 10b or 11b (enabled), an SIDLE
command strobe must be issued before the new configuration is taken into account. If it is altered
from 10b or 11b to 0 or 1 (disabled), an SPWD, SWOR, or SXOFF strobe must be issued.
When not using eWOR and RC calibration is enabled, staying in TX or RX mode over a long period of
time will cause internal heating of the chip, which again might cause the RC OSC period to increase.
It is therefore recommended to turn off RCOSC calibration during active mode.
9.10 Antenna Diversity and Multiple Path Transmission

CC120X has two different antenna diversity modes: Single-switch mode and continuous-switch mode.
Single switch mode is useful for very low power schemes where the device only checks each antenna
once for a signal and directly returns to power down if a signal is not detected (automated using the
eWOR feature). If a signal is found on the first antenna checked, it does not check the second
antenna.
Continuous mode is useful when staying in RX for longer intervals.
The antenna diversity algorithm can operate based on PQT or CS. The user can configure how the
device will act in regards to antenna diversity and RX termination as described in Table 33.
RFEND_CFG0.
ANT_DIV_RX_TERM_CFG

Description

000
001
010

Antenna diversity and termination based on CS/PQT are disabled
RX termination base on CS is enabled (Antenna diversity OFF). See 9.5.2 for details.
Single-switch antenna diversity on CS enabled.
One or both antenna is CS evaluated once and RX will terminate
if CS failed on both antennas.
Continuous-switch antenna diversity on CS enabled.
Antennas are switched until CS is asserted or RX timeout occurs
(if RX timeout is enabled)
RX termination base on PQT is enabled (Antenna diversity OFF).
See 9.5.3 for details.
Single-switch antenna diversity on PQT enabled.
One or both antenna is PQT evaluated once and RX will terminate if PQT is not
reached on any of the antennas.
Continuous-switch antenna diversity on PQT enabled.
Antennas are switched until PQT is reached or RX timeout occurs
(if RX timeout is enabled)
Reserved

011

100
101

110

111

Table 33: RFEND_CFG0.ANT_DIV_RX_TERM_CFG Setting

SWRU346B

Page 73 of 114

CC120X
9.10.1 Antenna Diversity Features
The device supports antenna diversity by controlling an external RF switch using the
ANTENNA_SELECT control signal available on GPIO (IOCFGx.GPIOx_CFG = ANTENNA_SELECT
(36)).
24

The device will remember the last antenna used (when not entering SLEEP mode ) and use the last
antenna for the next RX or TX transition. Staying with the same antenna will make sure:
In RX, that the last antenna used for good reception will be the first one to be checked
(minimize time for the next reception)
In TX, the device will transmit acknowledge with the same antenna that received the packet.
9.11 Random Number Generator
A random number generator is available and can be enabled by setting RNDGEN.RNDGEN_EN = 1. A
random number can be read from RNDGEN.RNDGEN_VALUE in any state, but the number will be
further randomized when in RX by XORing the feedback with receiver noise.
9.12 RF Programming
RF programming in CC120X is given by two factors; the VCO frequency programming and the LO
divider programming (RF band selection). The relation is given in Equation 27 below.

f RF

fVCO
[Hz]
LO Divider

Equation 27: Radio Frequency
The VCO frequency is given by the 24 bit (unsigned) frequency word FREQ located in the FREQ2,
FREQ1, and FREQ0 registers. There is also a possibility to perform VCO frequency offset
programming, given by the 16 bit (signed) frequency offset word FREQOFF located in the FREQOFF1
and FREQOFF0 registers. This is intended to adjust for crystal intolerance or fine adjustments of the
RF programming.

fVCO

FREQ
f XOSC
216

FREQOFF
f XOSC [Hz]
218

Equation 28: VCO Frequency
Note that the FREQOFF programming and FREQOFF_EST (found in FREQOFF_EST1 and
FREQOFF_EST0) have identical formats hence the frequency estimate can be accumulated directly to
the FREQOFF programming. This can be done either manually or automatically through the SAFC
command strobe. A SAFC command strobe can be issued in any state but does not take effect until
the next time the radio enters active mode (TX or RX).

In SLEEP mode the GDIOx pin will be hardwired to 0 or 1 depending on which GDIO pin is used
and what the value of IOCFGx_GPIOx_INV is. Please see Section 3.4 for more details.
SWRU346B

Page 74 of 114

CC120X
The LO divider/band select decoding is shown in Table 34.
FS_CFG.FSD_BANDSELECT
0000 - 0001
0010
0011
0100
0101
0110
0111
1000
1001
1010
1011
1100 - 1111

LO Divider
4
8
12
16
20
24
-

RF Band [MHz]
Not in use
820 - 960
Not in use
410 - 480
Not in use
273.3 - 320
Not in use
205 - 240
Not in use
164 - 192
136.7 - 160
Not in use

Table 34: RF Band Selection Decoding
Since the RF band is determined by the LO divider setting, the different RF bands will also have
different frequency resolution. Note that the frequency offset word is related to the VCO frequency
programming, and hence any crystal inaccuracy compensation is therefore independent of the
selected RF band.
See Table 35 for an overview of the RF resolution.
RF Band [MHz]
820 - 960
410 - 480
273.3 - 320
205 - 240
164 - 192
136.7 - 160

RF Programming Resolution [Hz]
38.1
19.1
12.7
9.5
7.6
6.4

Table 35: RF Programming Resolution
9.13 Frequency Synthesizer Configuration
If any frequency programming registers are altered when the frequency synthesizer is running, the
synthesizer may give an undesired response. Hence, the frequency programming should only be
updated when the radio is in the IDLE state.
9.14 IF Programming
The IF frequency is programmed through the IF_MIX_CFG.CMIX_CFG register field. The supported
IF frequencies (fIF) are listed in Table 36. The decimation factor is given by
CHAN_BW.ADC_CIC_DECFACT.
CMIX_CFG
0
1

Decimation Factor
12
24
0
0
-833.33
-416.67

48
0
-208.33

Comment

-555.56

-277.78

-138.89

-416.67

-208.33

-104.17

4
5

0
833.33

0
416.67

0
208.33

555.56

277.78

138.89

416.67

208.33

104.17

Zero-IF

f xosc
Decimation Factor
f xosc
f IF
Decimation Factor
f xosc
f IF
Decimation Factor
Zero-IF
f xosc
f IF
Decimation Factor
f xosc
f IF
Decimation Factor
f xosc
f IF
Decimation Factor
f IF

4
6
8

Table 36: IF Frequency [kHz]
SWRU346B

Page 75 of 114

CC120X
9.15 FS Calibration
The internal on-chip FS characteristics will vary with temperature and supply voltage changes as well
as the desired operating frequency. In order to ensure reliable operation, CC120X includes frequency
synthesizer self-calibration circuitry. This calibration should be done regularly, and must be performed
after turning on power and before using a new radio frequency.

CC120X has one manual calibration option (using the SCAL strobe), and three automatic calibration
options that are controlled by the SETTLING_CFG.FS_AUTOCAL setting:
Calibrate when going from IDLE to either RX or TX (or FSTXON)
Calibrate when going from either RX or TX to IDLE automatically
Calibrate every fourth time when going from either RX or TX to IDLE automatically
If the radio goes from TX or RX to IDLE by issuing an SIDLE strobe, calibration will not be performed.
Note: The calibration values are maintained in SLEEP mode, so the calibration is still valid
after waking up from SLEEP mode unless supply voltage or temperature has changed
significantly.
9.16 FS Out of Lock Detection
To check whether the PLL is out of lock, the user can enable the lock detector through the
FS_LOCK_EN bit in the FS_CFG register. The lock indication can either be read through
FSCAL_CTRL.LOCK or set available on GDO0 or GDO1 (IOCFG0/1.GPIO0/1_CFG = LOCK (35))
as an interrupt to the MCU. A negative transition on the lock indication indicates that the FS is out of
lock. The state of the LOCK signal is only valid in RX, TX, and FSTXON state.
Note that the lock detector average time is configurable and can be set through the
FS_CAL0.LOCK_CFG register field.

SWRU346B

Page 76 of 114

CC120X
10 AES
The CC120X contains an AES accelerator that can be used as a stand-alone AES module for AES
block operations. In this mode the MCU write and read back data over SPI to perform security
operations for maximum flexibility.
In addition there are built in commands to do automatic in-line security operations on the FIFO
content for minimum impact on MCU / SPI traffic.
10.1 AES Block Operation
To encrypt a 128 bit data block with the AES module using cipher block chaining (CBC), the following
procedure must be followed:
Write the 128 bit long AES key to the key location in the AES workspace (AES_KEY15 is the 7
MSB and starts at address 0x2FE0)
Write the 128 bit data block to the buffer location in the AES workspace (AES_BUFFER15 is the
7 MSB and starts at address 0x2FF0)
Execute encryption by setting AES.AES_RUN = 1. The bit will be set low by HW when
operation is finished.
Read encrypted data block from the buffer location in the AES workspace (address 0x2FF0)
10.2 AES Commands
The CC120x has built-in high level AES commands that can be called when the radio is in IDLE state
(these commands must not be called from any other states). These high level commands can
accelerate AES operations on the FIFO content and are triggered by issuing an SIDLE strobe while
the radio is in IDLE state. The AES commands are controlled by the MARC_SPARE.AES_COMMANDS
register field.
Table 37 shows the different AES commands.
MARC_SPARE.AES_COMMANDS
0x09
0x0A

Command
AES_TXFIFO
AES_RXFIFO

Description
AES CTR on the TX FIFO content
AES CTR on the RX FIFO content

Table 37: AES Commands
GPIO0 will be asserted when an AES command is activated, and de-asserted when the AES
command is completed if IOCFG0.GPIO0_CFG = AES_COMMAND_ACTIVE (22).
10.3 AES Parameters
Several parameters are needed for each AES command. These parameters must be written to given
25
locations in the AES command workspace (part of the free area) using direct memory access . The
following sections show where to write which parameters for each of the two AES commands
available.
10.3.1 AES TXFIFO
The AES_TXFIFO command is used to perform CTR on the TX FIFO content. Parameters needed to
be initialized are shown in Table 38. The nonce is located at memory location 0x80 in the AES
command workspace (free area, SERIAL_STATUS.SPI_DIRECT_ACCESS_CFG = 1) and are
reached using direct memory access (0x3E is the command preceding the address).
Address
0xF0

0xF2

Parameter
Pointer to first entry in the TXFIFO to encrypt (the packet
must always be written to a flushed TXFIFO meaning that
the first byte in the packet is at location 0x00)
Number of bytes in the TXFIFO that shall be encrypted

Table 38: AES TXFIFO Parameters

Direct memory access starts with the command 0x3E (see Table 3 for more details)
SWRU346B

Page 77 of 114

CC120X
10.3.2 AES RXFIFO
The AES_TXFIFO command is used to perform CTR on the RX FIFO content. Parameters needed to
be initialized are shown in Table 39. The nonce is located at memory location 0x80 in the AES
command workspace (free area, SERIAL_STATUS.SPI_DIRECT_ACCESS_CFG = 1) and are
reached using direct memory access (0x3E is the command preceding the address).
Address
0xF0

0xF2

Parameter
Pointer to first entry in the RXFIFO to decrypt (the RXFIFO
must be flushed before the packet is received meaning that
the first byte in the packet is at location 0x00)
Number of bytes in the RXFIFO that shall be decrypted

Table 39: RXFIFO Parameters
10.4 AES TX/RXFIFO Operation
The following section will show the steps necessary to encrypt the TXFIFO content and decrypt the
RXFIFO content using counter mode (CTR).
10.4.1 TXFIFO Encryption
Make sure the radio is in IDLE state
Flush the TXFIFO using the SFTX command strobe
Write the packet to the TXFIFO
Set MARC_SPARE.AES_COMMAND = 0x09 (AES_TXFIFO)
Write the 128 bit long AES key to the key location in the AES workspace (AES_KEY15 is the 7
MSB and starts at address 0x2FE0)
Set SERIAL_STATUS.SPI_DIRECT_ACCESS_CFG = 1
Write the AES TXFIFO parameters (see Table 38) to the AES command workspace using
direct memory access
Write the nonce to address 0x80 in the AES command workspace using direct memory access
Strobe SIDLE to execute the AES_TXFIFO command
A falling edge on GPIO0 indicates that the operation is done (if IOCFG0.GPIO0_CFG
AES_COMMAND_ACTIVE (22)) and an STX strobe can be issued.

10.4.2 RXFIFO Decryption
Make sure the radio is in IDLE state
Flush the RXFIFO using the SFRX command strobe
Issue an SRX strobe and wait for a packet to be received
Set MARC_SPARE.AES_COMMAND = 0x0A (AES_RXFIFO)
Write the 128 bit long AES key to the key location in the AES workspace (AES_KEY15 is the 7
MSB and starts at address 0x2FE0)
Set SERIAL_STATUS.SPI_DIRECT_ACCESS_CFG = 1
Write the AES RXFIFO parameters (see Table 39) to the AES command workspace using
direct memory access
Write the nonce to address 0x80 in the AES command workspace using direct memory access
Strobe SIDLE to execute the AES_RXFIFO command
A falling edge on GPIO0 indicates that the operation is done (if IOCFG0.GPIO0_CFG
AES_COMMAND_ACTIVE (22)) and the RXFIFO can be read.

SWRU346B

Page 78 of 114

CC120X
11 System Considerations and Guidelines
11.1 Voltage Regulators

CC120X contains several on-chip linear voltage regulators that generate the supply voltages needed by
the low-voltage modules. These voltage regulators are invisible to the user, and can be viewed as
integral parts of the various modules. The user must however make sure that the absolute maximum
ratings and required pin voltages are not exceeded.
By setting the CSn pin low, the voltage regulator to the digital core turns on and the crystal oscillator
starts. The SO pin on the SPI interface must go low before the first positive edge of SCLK (setup time
is given in Table 1.If the chip is programmed to enter power-down mode (SPWD or SWOR strobe
issued), the power will be turned off after CSn goes high. The power and crystal oscillator will be
turned on again when CSn goes low.
The voltage regulator for the digital core requires one external decoupling capacitor.
The voltage regulator output should only be used for driving the CC120X.
11.2 SRD Regulations
International regulations and national laws regulate the use of radio receivers and transmitters. Short
Range Devices (SRDs) for license free operation below 1 GHz are usually operated in the 169 MHz,
433 MHz, 868 MHz, 915 MHz, or 950 MHz frequency bands. The CC120X is specifically designed for
operation in these bands.
Please note that compliance with regulations is dependent on the complete system performance. It is
the customer’s responsibility to ensure that the system complies with regulations.
11.3 Frequency Hopping and Multi-Channel Systems
The 433 MHz, 868 MHz, or 915 MHz bands are shared by many systems both in industrial, office, and
home environments. It is therefore recommended to use frequency hopping spread spectrum (FHSS)
or a multi-channel protocol because frequency diversity makes the system more robust with respect
to interference from other systems operating in the same frequency band. FHSS also combats
multipath fading.

CC120X is highly suited for FHSS or multi-channel systems due to its agile frequency synthesizer and
effective communication interface. Using the packet handling support and data buffering is also
beneficial in such systems as these features will significantly offload the host controller.
Charge pump current, VCO current, and VCO capacitance array calibration data is required for each
frequency when implementing frequency hopping for CC120X. There are 2 ways of obtaining the
calibration data from the chip:
1) Frequency hopping with calibration for each hop.
2) Fast frequency hopping without calibration for each hop can be done by performing the necessary
calibration at start-up and saving the resulting FS_CHP, FS_VCO4, and FS_VCO2 register values in
MCU memory. Between each frequency hop, the calibration process can then be replaced by writing
the calibration values that corresponds to the next RF frequency.
The recommended settings change with frequency. This means that one should always use
SmartRF Studio to get the correct settings for a specific frequency before doing a calibration,
regardless of which calibration method is being used.
11.4 Continuous Transmissions
In data streaming applications, the CC120X opens up for continuous transmissions at an effective data
rate of up to 1 Mbps. As the modulation is done with a closed loop PLL, there is no limitation in the
length of a transmission (open loop modulation used in some transceivers often prevents this kind of
continuous data streaming and reduces the effective data rate).
11.5 Battery Operated Systems
In low power applications, the SLEEP state with the crystal oscillator core switched off should be used
when the CC120X is not active. It is possible to leave the crystal oscillator core running in the SLEEP
state if start-up time is critical. The eWOR functionality should be used in low power applications.
SWRU346B

Page 79 of 114

CC120X
12 Register Description
For a detailed description of the register fields, please see SmartRF Studio [1]
IOCFG3 - GPIO3 Pin Configuration
Bit #

Name

Reset

R/W

Description

GPIO3_ATRAN

0x00

R/W

Analog transfer enable
0
Standard digital pad

GPIO3_INV

0x00

R/W

5:0

GPIO3_CFG

0x06

R/W

Pad in analog mode (digital GPIO input and output disabled)

Invert output enable
0

Invert output disabled

Invert output enable

Output selection
Default: PKT_SYNC_RXTX

IOCFG2 - GPIO2 Pin Configuration
Bit #

Name

Reset

R/W

Description

GPIO2_ATRAN

0x00

R/W

Analog transfer enable. Refer to IOCFG3

GPIO2_INV

0x00

R/W

Invert output enable. Refer to IOCFG3

5:0

GPIO2_CFG

0x07

R/W

Output selection
Default: PKT_CRC_OK

IOCFG1 - GPIO1 Pin Configuration
Bit #

Name

Reset

R/W

Description

GPIO1_ATRAN

0x00

R/W

Analog transfer enable. Refer to IOCFG3

GPIO1_INV

0x00

R/W

Invert output enable. Refer to IOCFG3

5:0

GPIO1_CFG

0x30

R/W

Output selection
Default: HIGHZ
Note that GPIO1 is shared with the SPI and act as SO when CSn is asserted (active low).
The system must ensure pull up/down on this pin

IOCFG0 - GPIO0 Pin Configuration
Bit #

Name

Reset

R/W

Description

GPIO0_ATRAN

0x00

R/W

Analog transfer enable. Refer to IOCFG3

GPIO0_INV

0x00

R/W

Invert output enable. Refer to IOCFG3

5:0

GPIO0_CFG

0x3C

R/W

Output selection
Default: EXT_OSC_EN

SYNC3 - Sync Word Configuration [31:24]
Bit #

Name

Reset

R/W

Description

7:0

SYNC31_24

0x93

R/W

Sync word [31:24]

SYNC2 - Sync Word Configuration [23:16]
Bit #

Name

Reset

R/W

Description

7:0

SYNC23_16

0x0B

R/W

Sync word [23:16]

SYNC1 - Sync Word Configuration [15:8]
Bit #

Name

Reset

R/W

Description

7:0

SYNC15_8

0x51

R/W

Sync word [15:8]

SYNC0 - Sync Word Configuration [7:0]
Bit #

Name

Reset

R/W

Description

7:0

SYNC7_0

0xDE

R/W

Sync word [7:0]

SWRU346B

Page 80 of 114

CC120X
SYNC_CFG1 - Sync Word Configuration Reg. 1
Bit #

Name

Reset

R/W

Description

7:5

SYNC_MODE

0x05

R/W

Sync word configuration. When SYNC_MODE = 0, all samples (noise or data)
received after RX mode is entered will either be put in the RX FIFO or output on a
GPIO configured as SERIAL_RX. Note that when 4'ary modulation is used the
sync word uses 2'ary modulation (the symbol rate is kept the same)
000
No sync word

4:0

SYNC_THR

0x0A

R/W

001

11 bits [SYNC15_8[2:0]:SYNC7_0]

010

16 bits [SYNC15_8: SYNC7_0]

011

18 bits [SYNC23_16[1:0]: SYNC15_8: SYNC7_0]

100

24 bits [SYNC23_16: SYNC15_8: SYNC7_0]

101

32 bits [SYNC31_24: SYNC23_16: SYNC15_8: SYNC7_0]

110

16H bits [SYNC31_24: SYNC23_16]

111

16D bits (DualSync search). When this setting is used in TX mode
[SYNC15_8:SYNC7_0] is transmitted

Soft decision sync word threshold. A sync word is accepted when the calculated
sync word qualifier value (PQT_SYNC_ERR.SYNC_ERROR) is less than
SYNC_THR/2). A low threshold value means a strict sync word qualifier (sync word
must be of high quality to be accepted) while a high threshold value will accept
sync word of a poorer quality (increased probability of detecting ‘false’ sync
words)

SYNC_CFG0 - Sync Word Configuration Reg. 0
Bit #

Name

Reset

R/W

7:6

SYNC_CFG0_NOT_USED

0x00

AUTO_CLEAR

0x00

R/W

Description
Auto clear enable
Auto clear of symbol rate offset estimate when TOC_CFG.TOC_LIMIT ≠ 0 and
MDMCFG1.CARRIER_SENSE_GATE = 1. The symbol rate offset estimate will be
cleared when CARRIER_SENSE is de-asserted.
Auto clear of IQIC coefficient when IQIC.IQIC_EN = 1. The receiver image
compensation coefficient is cleared when the image signal dissappears
0

RX_CONFIG_LIMITATION

0x00

R/W

0
1
3

PQT_GATING_EN

0x00

R/W

EXT_SYNC_DETECT

0x00

R/W

1:0

STRICT_SYNC_CHECK

0x03

R/W

Symbol Rate

RX Filter BW
2

Symbol Rate RX Filter BW

f xosc
[Hz]
Decimation Factor CHAN_BW.BB _CIC_DECFACT 4

f xosc
[Hz]
Decimation Factor CHAN_BW.BB _CIC_DECFACT 2

PQT gating enable
0
PQT gating disabled
1

Auto clear disabled

1
Auto clear enabled
Receiver configuration limitation. The decimation factor is given by
CHAN_BW.ADC_CIC_DECFACT.
When this bit is set, RX filter BW must be less than 1500 kHz.
When RX_CONFIG_LIMITATION = 1 the AGC_CFG1.AGC_WIN_SIZE should
be incremented by 1 and the wait time between AGC gain adjustment
programmed through AGC_CFG1.AGC_SETTLE_WAIT should be doubled

PQT gating enabled. The demodulator will not start to look for a sync
word before a preamble is detected (i.e. PQT_REACHED is asserted). The
preamble detector must be enabled for this feature to work
(PREAMBLE_CFG0.PQT_EN = 1)

External sync detect can be used in blind mode to make the receiver change
modem parameters after a sync word has been detected by the MCU. GPIO2
needs to be configured as SYNC_DETECT (IOCFG2.GPIO2_CFG = HIGHZ (48))
and the MCU should set this input when a sync word is detected. This will make
the receiver switch modem parameters from sync search settings to packet
receive settings similar to what is done in FIFO mode/normal mode
0
External sync detect disabled
1

External sync detect enabled

Strict sync word bit check. This feature is useful in cases where the sync word has
weak correlation properties (level 3 is the strictest sync check)
00
Strict sync word check level 1
01

Strict sync word check level 2

Strict sync word check level 3

Strict sync word check disabled

DEVIATION_M - Frequency Deviation Configuration
Bit #

Name

Reset

R/W

Description

7:0

DEV_M

0x06

R/W

Frequency deviation (mantissa part)
Maximum fdev = ~1.2 MHz
f xosc
DEV_E > 0:
f dev
(256 DEV _ M ) 2 DEV _ E [Hz]
2 22
f xosc
DEV_E = 0:
f dev
DEV _ M [Hz]
2 21

SWRU346B

Page 81 of 114

CC120X
MODCFG_DEV_E - Modulation Format and Frequency Deviation Configuration
Bit #

Name

Reset

R/W

Description

7:6

MODEM_MODE

0x00

R/W

Modem mode configuration
00

Normal mode

DSSS repeat mode. Requires that SYNC_CFG1.SYNC_MODE = 1 or
010b.
TX mode: PKT_CFG2.PKT_FORMAT = 0
RX mode: PKT_CFG2.PKT_FORMAT = 1
MDMCFG1.FIFO_EN = 0
MDMCFG0.TRANSPARENT_MODE_EN = 0
In RX mode, data is only available on GPIO by configuring
IOCFGx.GPIOx_CFG = 18

5:3

2:0

MOD_FORMAT

DEV_E

0x00

0x03

R/W

DSSS PN mode. Both FIFO mode and synchronous serial mode are
supported (PKT_CFG2.PKT_FORMAT = 0 or 1)

Carrier sense mode. This mode can be used to measure the channel
power (sync search is disabled in this mode)

Modulation format
000

2-FSK

001

2-GFSK

010

Reserved

011
100

ASK/OOK
4-FSK

101

4-GFSK

110

Reserved

111

Reserved

Frequency deviation (exponent part). See DEVIATION_M

DCFILT_CFG - Digital DC Removal Configuration
Bit #

Name

Reset

R/W

DCFILT_CFG_NOT_USED

0x00

DCFILT_FREEZE_COEFF

0x01

R/W

5:3

DCFILT_BW_SETTLE

0x01

R/W

Description
DC filter override
0

DC filter algorithm estimates and compensates for DC error

Manual DC compensation through registers DCFILTOFFSET_I1,
DCFILTOFFSET_I0, DCFILTOFFSET_Q1, and DCFILTOFFSET_Q0

Settling period of high pass DC filter after AGC adjustment

Sample Rate

f XOSC
[Hz]
Decimation Factor

The decimation factor is 12, 24, or 48, depending on the
CHAN_BW.ADC_CIC_DECFACT setting

2:0

DCFILT_BW

0x04

R/W

000

8 samples

001

16 samples

010

32 samples

011
100

64 samples
128 samples

101

128 samples

110

128 samples

111

128 samples

Cut-off frequency (fCut-Off ) of high pass DC filter
DCFILT_BW = 0 - 011b:

f Cutt -Off DC Filter ~

f XOSC
Decimation Factor 2 ( DCFILT _ BW

[Hz]

DCFILT_BW = 110b - 111b:

f Cutt -Off DC Filter ~

f XOSC
Decimation Factor 2 ( 2 DCFILT _ BW )

[Hz]

The decimation factor is 12, 24, or 48, depending on the
CHAN_BW.ADC_CIC_DECFACT setting

SWRU346B

Page 82 of 114

CC120X
PREAMBLE_CFG1 - Preamble Configuration Reg. 1
Bit #

Name

Reset

R/W

7:6

PREAMBLE_CFG1_NOT_USED

0x00

5:2

NUM_PREAMBLE

0x05

R/W

1:0

PREAMBLE_WORD

0x00

R/W

Description
Sets the minimum number of preamble bits to be transmitted
0000
0001

No preamble
0.5 byte

0010

1 byte

0011

1.5 bytes

0100

2 bytes

0101

3 bytes

0110

4 bytes

0111

5 bytes

1000

6 bytes

1001

7 bytes

1010

8 bytes

1011
1100

12 bytes
24 bytes

1101

30 bytes

1110

Reserved

1111

Reserved

Preamble byte configuration. PREAMBLE_WORD determines how a preamble
byte looks like. Note that when 4'ary modulation is used the preamble uses
2'are modulation (the symbol rate is kept the same)
00
10101010 (0xAA)
01

01010101 (0x55)

00110011 (0x33)

11001100 (0xCC)

PREAMBLE_CFG0 - Preamble Configuration Reg. 0
Bit #

Name

Reset

R/W

Description

PQT_EN

0x01

R/W

Preamble detection enable

6:4

3:0

PQT_VALID_TIMEOUT

PQT

0x05

0x0A

R/W

Preamble detection disabled

Preamble detection enabled

PQT start-up timer. PQT_VALID_TIMEOUT sets the number of symbols that
must be received before PQT_VALID is asserted
000

11 symbols

001

12 symbols

010

13 symbols

011

15 symbols

100
101

16 symbols
17 symbols

110

24 symbols

111

32 symbols

Soft decision PQT. A preamble is detected when the calculated preamble
qualifier value (PQT_SYNC_ERR.PQT_ERROR) is less than PQT. A low
threshold value means a strict preamble qualifier (preamble must be of high
quality to be accepted) while a high threshold value will accept preamble of a
poorer quality (increased probability of detecting ‘false’ preamble)

SWRU346B

Page 83 of 114

CC120X
IQIC - Digital Image Channel Compensation Configuration
Bit #

Name

Reset

R/W

Description

IQIC_EN

0x01

R/W

IQ image compensation enable. When this bit is set the following must be true:
fIF > RX filter BW
(see IF_MIX_CFGCMIX_CFG for how to program fIF)
0

5:4

3:2

1:0

IQIC_UPDATE_COEFF_EN

IQIC_BLEN_SETTLE

IQIC_BLEN

IQIC_IMGCH_LEVEL_THR

0x01

0x00

0x01

0x00

R/W

IQ image compensation disabled

1
IQ image compensation enabled
IQIC update coefficients enable
0

IQIC update coefficient disabled (IQIE_I1, IQIE_I0, IQIE_Q1,
and IQIE_Q0 registers are not updated)

IQIC update coefficients enabled (IQIE_I1, IQIE_I0, IQIE_Q1,
and IQIE_Q0 registers are updated)

IQIC block length when settling. The IQIC module will do a coarse estimation of
IQ imbalance coefficients during settling mode. Long block length increases
settling time and improves image rejection
00

8 samples

32 samples

128 samples

256 samples

IQIC block length. Long block length increases settling time and improves image
rejection
00

8 samples

01
10

32 samples
128 samples

256 samples

IQIC image channel level threshold. Image rejection will be activated when image
carrier is present. The IQIC image channel level threshold is an image carrier
detector. High threshold imply that image carrier must be high to enable IQIC
compensation module
00
> 256
01

> 512

> 1024

> 2048

CHAN_BW - Channel Filter Configuration
Bit #

Name

Reset

R/W

7:6

ADC_CIC_DECFACT

0x02

R/W

5:0

BB_CIC_DECFACT

0x14

R/W

Description
ADC_CIC_DECFACT is a table index which programs the first decimation filter and
program the RX filter bandwidth. ADC_CIC_DECFACT table index:
00
Decimation factor 12
01

Decimation factor 24

Decimation factor 48

11
Reserved
BB_CIC_DECFACT configures the RX filter BW by changing decimation factor in
the second decimation filter
ADC_CIC_DECFACT
BB_CIC_DECFACT
Device
RX Filter BW
Range [kHz]
CC1200
12
1 - 44
37.9 - 1666.7
CC1200

1 - 44

18.9 - 833.3

CC1200

1 - 44

9.5 - 416.7

CC1201

1 - 33

50.5 - 1666.7

CC1201

1 - 16

52.1 - 833.3

CC1201

1-8

52.1 - 416.7

SWRU346B

Page 84 of 114

CC120X
MDMCFG2 - General Modem Parameter Configuration Reg. 2
Bit #

Name

Reset

R/W

Description

7:6

ASK_SHAPE

0x00

R/W

Sets the resolution of an ASK bit transition (# of points). The following rule must
be satisfied:
ASK_SHAPE < 3:
MDMCFG2.UPSAMPLER_P ≥ 4 - PA_CFG0.RAMP_SHAPE + ASK_SHAPE
ASK_SHAPE = 3:
MDMCFG2.UPSAMPLER_P ≥ 5 - PA_CFG0.RAMP_SHAPE + ASK_SHAPE

5:4

SYMBOL_MAP_CFG

0x00

R/W

128

Symbol map configuration. Configures the modulated symbol mapping
definition from data bit to modulated symbols.
For 2'ary modulation schemes the symbol mapping definition is as follows:
SYMBOL_MAP_CFG
Data bit

−Dev [AMIN]

Dev [AMAX]

−Dev [AMIN]

OOK/ASK: AMAX = Maximum amplitude, AMIN = Minimum amplitude
For 4'ary modulation schemes the symbol mapping definition is as follows:
SYMBOL_MAP_CFG

3:1

UPSAMPLER_P

0x04

R/W

Data bit

−Dev/3

−Dev

Dev/3

Dev

−Dev

−Dev/3

Dev

Dev/3

Dev

−Dev/3

−Dev

Dev

Dev/3

−Dev

−Dev/3

UPSAMPLER_P configures the variable upsampling factor P for the TX
upsampler. The total upsampling factor = 16∙P. The upsampler factor P must
satisfy the following:

Symbol Rate 16 P

f XOSC , where P should be as large as possible
4

The upsampler reduces repetitive spectrum at 16·symbol rate

CFM_DATA_EN

0x00

R/W

000

TX upsampler factor P = 1 (bypassed)

001

TX upsampler factor P = 2

010

TX upsampler factor P = 4

011

TX upsample factor P = 8

100

TX upsampler Factor P = 16

101

TX upsampler Factor P = 32

110

TX upsampler Factor P = 64

111

Not used

Custom frequency modulation enable
0
1

SWRU346B

CFM mode disabled
CFM mode enabled (write frequency word directly)

Page 85 of 114

CC120X
MDMCFG1 - General Modem Parameter Configuration Reg. 1
Bit #

Name

Reset

R/W

Description

CARRIER_SENSE_GATE

0x00

R/W

When CARRIER_SENSE_GATE is 1, the demodulator will not start to look for a
sync word before CARRIER_SENSE is asserted

2:1

FIFO_EN

MANCHESTER_EN

INVERT_DATA_EN

COLLISION_DETECT_EN

DVGA_GAIN

SINGLE_ADC_EN

0x01

0x00

0x03

0x00

R/W

Search for sync word regardless of CS

Do not start sync search before CARRIER_SENSE is asserted

FIFO enable. Specifies if data to/from modem will be passed through the FIFOs or
directly to the serial pin
0

Data in/out through the serial pin(s) (the FIFOs are bypassed)

Data in/out through the FIFOs

Manchester mode enable. Manchester encoding/decoding is only applicable to
payload data including optional CRC. Manchester encoding/decoding is not
supported for 4-(G)FSK
0

NRZ

Manchester encoding/decoding

Invert data enable. Invert payload data stream in RX and TX (only applicable to
payload data including optional CRC)
0

Invert data disabled

Invert data enabled

Collision detect enable. After a sync word is detected (SYNC_EVENT asserted),
the receiver will always receive a packet. If collision detection is enabled, the
receiver will continue to search for preamble. If a new preamble is found
(PQT_REACHED asserted) and the RSSI has increased 10 or 16 dB during packet
reception (depending on AGC_CFG1.RSSI_STEP_THR) a collision is detected and
the COLLISION_FOUND flag will be asserted
0

Collision detect disabled

Collision detect enabled

Fixed DVGA gain configuration. The DVGA configuration has impact on the RSSI
offset
00
0 dB DVGA (preferred setting for RX filter bandwidth < 100 kHz)
01

-18 dB DVGA (preferred setting for RX filter bandwidth ≥ 100 kHz)

Reserved

Configure the number of active receive channels. If this bit is set the power
consumption will be reduced but the sensitivity level will be reduced by ~3 dB.
Image rejection will not work
0

IQ-channels

Only I-channel

SWRU346B

Page 86 of 114

CC120X
MDMCFG0 - General Modem Parameter Configuration Reg. 0
Bit #

Name

Reset

R/W

Description

MDMCFG0_RESERVED7

0x00

R/W

For test purposes only, use values from SmartRF Studio

TRANSPARENT_MODE_EN

0x00

R/W

Transparent mode enable
0
1

5:4

TRANSPARENT_INTFACT

0x00

R/W

Transparent mode disabled
Transparent mode enabled

Transparent signal interpolation factor. The sample rate gives the jitter of the
samples and the sample rate is given by

Sample Rate

f XOSC Interpolat ion Factor
[Hz]
Decimation Factor CHAN_BW.BB _CIC_DECFACT

The decimation factor is given by CHAN_BW.ADC_CIC_DECFACT while the
interpolation factor is given below
00
1x transparent signal interpolated one time before output (reset)

1:0

DATA_FILTER_EN

VITERBI_EN

MDMCFG0_RESERVED1_0

0x01

R/W

2x transparent signal interpolated two times before output

4x transparent signal interpolated four times before output

Reserved

Transparent data filter and extended data filter enable. Enabling transparent
data filter and/or extended data filter might improve sensitivity.
When TRANSPARENT_MODE_EN = 0 this bit should only be set when RX
filter bandwidth/symbol rate > 10 and TOC_CFG.TOC_LIMIT = 0.
The table below shows the status of the transparent data filter and the
extended data filter for all combinations of TRANSPARENT_MODE_EN (MSB)
and DATA_FILTER_EN (LSB)
00

Transparent data filter disabled and extended data filter disabled

Transparent data filter disabled and extended data filter enabled

Transparent data filter disabled and extended data filter disabled

Transparent data filter enabled and extended data filter disabled

Viterbi detection enable. Enabling Viterbi detection improves the sensitivity.
The latency from the antenna to the signal is available in the RXFIFO or on
the GPIO is increased by 5 bits for 2-ary modulation formats and 10 bits for
4-ary modulation formats. Minimum packet length = 2 bytes when Viterbi
detection and 4-(G)FSK is enabled
0

Viterbi detection disabled

Viterbi detection enabled

For test purposes only, use values from SmartRF Studio

SWRU346B

Page 87 of 114

CC120X
SYMBOL_RATE2 - Symbol Rate Configuration Exponent and Mantissa [19:16]
Bit #

Name

Reset

R/W

Description

7:4

SRATE_E

0x04

R/W

Symbol rate (exponent part)
SRATE_E > 0:
SRATE_E = 0:

3:0

SRATE_M_19_16

0x03

R/W

(2 20

SRATE _ M ) 2 SRATE _ E
f XOSC [ksps]
2 39
SRATE _ M
f XOSC [ksps]
238

RSymbol

Modulation format /
data encoding
2-(G)FSK

Data rate/symbol rate ratio

4-(G)FSK

Manchester mode

0.5

DSSS mode

1/spreading factor

FEC

0.5

Symbol rate (mantissa part [19:16]). See SRATE_E

SYMBOL_RATE1- Symbol Rate Configuration Exponent and Mantissa [15:8]
Bit #

Name

Reset

R/W

Description

7:0

SRATE_M_15_8

0xA9

R/W

Symbol rate (mantissa part [15:8]). See SYMBOL_RATE2

SYMBOL_RATE0 - Symbol Rate Configuration Exponent and Mantissa [7:0]
Bit #

Name

Reset

R/W

Description

7:0

SRATE_M_7_0

0x2A

R/W

Symbol rate (mantissa part [7:0]). See SYMBOL_RATE2

AGC_REF - AGC Reference Level Configuration
Bit #

Name

Reset

R/W

Description

7:0

AGC_REFERENCE

0x36

R/W

AGC reference level. The AGC reference level must be higher than the minimum SNR
to the demodulator. The AGC reduces the analog front end gain when the magnitude
output from channel filter > AGC reference level. An optimum AGC reference level is
given by several conditions, but a rule of thumb is to use the formula:

AGC _ REFERENCE 10 log10 (RX Filter BW) 92 RSSI Offset
RX filter BW

AGC_REFERENCE

10 kHz

0x2F (MDMCFG1.DVGA_GAIN = 0, RSSI offset ≈ −99 dB)

100 kHz

0x27 (MDMCFG1.DVGA_GAIN = 1, RSSI offset ≈ −81 dB)

200 kHz

0x2D (MDMCFG1.DVGA_GAIN = 1, RSSI offset ≈ −81 dB)

500 kHz

0x2F (MDMCFG1.DVGA_GAIN = 1, RSSI offset ≈ −81 dB)

1600 kHz

0x33 (MDMCFG1.DVGA_GAIN = 1, RSSI offset ≈ −81 dB)

For zero-IF configuration, AGC hysteresis > 3 dB, or modem format which needs SNR
> 15 dB a higher AGC reference value is needed.

AGC_CS_THR - Carrier Sense Threshold Configuration
Bit #

Name

Reset

R/W

Description

7:0

AGC_CS_TH

0x00

R/W

AGC carrier sense threshold. Two's complement number with 1 dB resolution

AGC_GAIN_ADJUST - RSSI Offset Configuration
Bit #

Name

Reset

R/W

Description

7:0

GAIN_ADJUSTMENT

0x00

R/W

AGC gain adjustment. This register is used to adjust RSSI[11:0] to the actual carrier
input signal level to compensate for interpolation gains (two's complement with 1 dB
resolution)

SWRU346B

Page 88 of 114

CC120X
AGC_CFG3 - Automatic Gain Control Configuration Reg. 3
Bit #

Name

Reset

R/W

Description

7:5

AGC_SYNC_BEHAVIOUR

0x05

R/W

AGC behavior after sync word detection

4:0

AGC_MIN_GAIN

0x11

R/W

000

No AGC gain freeze. Keep computing/updating RSSI

001
010

AGC gain freeze. Keep computing/updating RSSI
No AGC gain freeze. Keep computing/updating RSSI (AGC slow
mode enabled)

011

Freeze both AGC gain and RSSI

100

No AGC gain freeze. Keep computing/updating RSSI

101

Freeze both AGC gain and RSSI

110

No AGC gain freeze. Keep computing/updating RSSI (AGC slow
mode enabled)

111

Freeze both AGC gain and RSSI

AGC minimum gain. Limits the AGC minimum gain compared to the preset
gain table range. AGC_MIN_GAIN can have a value in the range
0 to 17 when AGC_CFG2.FE_PERFORMANCE_MODE = 0 or 1,
0 to 13 when AGC_CFG2.FE_PERFORMANCE_MODE = 10b and
0 to 7 when AGC_CFG2.FE_PERFORMANCE_MODE = 11b

AGC_CFG2 - Automatic Gain Control Configuration Reg. 2
Bit #

Name

Reset

R/W

Description

START_PREVIOUS_GAIN_EN

0x00

R/W

Receiver starts with maximum gain value

Receiver starts from previous gain value

6:5

4:0

FE_PERFORMANCE_MODE

AGC_MAX_GAIN

0x01

0x00

R/W

Controls which gain tables to be applied
00

Optimized linearity mode

Normal operation mode

Low power mode with reduced gain range

Zero-IF mode

AGC maximum gain. Limits the AGC maximum gain compared to the preset
gain table range. AGC_MAX_GAIN can have a value in the range
0 to 17 when AGC_CFG2.FE_PERFORMANCE_MODE = 0 or 1,
0 to 13 when AGC_CFG2.FE_PERFORMANCE_MODE = 10b and
0 to 7 when AGC_CFG2.FE_PERFORMANCE_MODE = 11b

AGC_CFG1 - Automatic Gain Control Configuration Reg. 1
Bit #

Name

Reset

R/W

AGC_CFG1_NOT_USED

0x00

R/W

RSSI_STEP_THR

0x01

R/W

Description
AGC has a built in function to signal if there has been a step in the RSSI
value. During sync search the difference between the current and the
previous RSSI value is compared against the RSSI step (3 or 6 dB), while
during packet reception, the difference between the current value and the
value at sync found is compared against 10 or 16 dB
0
RSSI step is 3 dB during sync search
RSSI step is 10 dB during packet reception
1

RSSI step is 6 dB during sync search
RSSI step is 16 dB during packet reception

5:3

2:0

AGC_WIN_SIZE

AGC_SETTLE_WAIT

0x02

R/W

AGC integration window size for each value. Samples refer to the RX filter
sampling frequency, which is programmed to be 4 times the desired RX filter
BW
000

8 samples

001

16 samples

010

32 samples

011
100

64 samples
128 samples

101

256 samples

110

Reserved

111

Reserved

Sets the wait time between AGC gain adjustments
000

24 samples

001

32 samples

010

40 samples

011

48 samples

100

64 samples

101
110

80 samples
96 samples

111

127 samples

SWRU346B

Page 89 of 114

CC120X
AGC_CFG0 - Automatic Gain Control Configuration Reg. 0
Bit #

Name

Reset

R/W

Description

7:6

AGC_HYST_LEVEL

0x03

R/W

AGC hysteresis level. The difference between the desired signal level and the
actual signal level must be larger than AGC hysteresis level before the AGC
changes the front end gain

5:4

3:2

1:0

AGC_SLEWRATE_LIMIT

RSSI_VALID_CNT

AGC_ASK_DECAY

0x00

0x03

R/W

2 dB

4 dB

7 dB

11
10 dB
AGC slew rate limit. Limits the maximum front end gain adjustment
00

60 dB

30 dB

18 dB

9 dB

Gives the number of new input samples to the moving average filter (internal
RSSI estimates) that are required before the next update of the RSSI value.
The RSSI_VALID signal will be asserted from the first RSSI update.
RSSI_VALIDis available on a GPIO or can be read from the RSSI0 register
00

The OOK/ASK receiver uses a max peak magnitude (logic 1) tracker and low
peak magnitude (logic 0) tracker to estimate ASK_THRESHOLD (decision
level) as the average of the max and min value. The max peak magnitude value
is also used by the AGC to set the gain. AGC_ASK_DECAY controls the max
peak magnitude decay steps in OOK/ASK mode and defines the number of
samples required for the max peak level to be reduced to 10% when receiving
logic 0’s after receiving a logic 1.

SampleRate

f XOSC Interpolat ion Factor
[Hz]
Decimation Factor CHAN _ BW .BB _ CIC _ DECFACT

The decimation factor is given by CHAN_BW.ADC_CIC_DECFACT and the
interpolation factor is given by SYNC_CFG0.RX_CONFIG_LIMITATION as
follows:
RX_CONFIG_LIMITATION = 0: Int. factor = 2
RX_CONFIG_LIMITATION = 1: Int. factor = 4
00

1200 samples

2400 samples

4700 samples

9500 samples

FIFO_CFG - FIFO Configuration
Bit #

Name

Reset

R/W

Description

CRC_AUTOFLUSH

0x01

R/W

Automatically flushes the last packet received in the RX FIFO if a CRC error
occurred. If this bit has been turned off and should be turned on again, an SFRX
strobe must first be issued

6:0

FIFO_THR

0x00

R/W

Threshold value for the RX and TX FIFO. The threshold value is coded in
opposite directions for the two FIFOs to give equal margin to the overflow and
underflow conditions when the threshold is reached. I.e.; FIFO_THR = 0
means that there are 127 bytes in the TX FIFO and 1 byte in the RX FIFO,
while FIFO_THR = 127 means that there are 0 bytes in the TX FIFO and 128
bytes in the RX FIFO when the thresholds are reached

DEV_ADDR - Device Address Configuration
Bit #

Name

Reset

R/W

Description

7:0

DEVICE_ADDR

0x00

R/W

Address used for packet filtering in RX

SWRU346B

Page 90 of 114

CC120X
SETTLING_CFG - Frequency Synthesizer Calibration and Settling Configuration
Bit #

Name

Reset

R/W

7:5

SETTLING_CFG_NOT_USED

0x00

4:3

FS_AUTOCAL

0x01

R/W

2:1

LOCK_TIME

FSREG_TIME

0x01

R/W

Description
Auto calibration is performed:
00

Never (manually calibrate using SCAL strobe)

When going from IDLE to RX or TX (or FSTXON)

10
11

When going from RX or TX back to IDLE automatically
Every 4th time when going from RX or TX to IDLE automatically

Sets the time for the frequency synthesizer to settle to lock state. The table
shows settling after calibration and settling when switching between TX and
RX. Use values from SmartRF Studio
00
50/20 µs
01

75/30 µs

100/40 µs

150/60 µs

Frequency synthesizer regulator settling time. Use values from SmartRF Studio
0

30 µs

60 µs

FS_CFG - Frequency Synthesizer Configuration
Bit #

Name

Reset

R/W

7:5

FS_CFG_NOT_USED

0x00

FS_LOCK_EN

0x00

R/W

3:0

FSD_BANDSELECT

0x02

R/W

Description
Out of lock detector enable
0

Out of lock detector disabled

Out of lock detector enabled

Band select setting for LO divider
0000

Not in use

0001

Not in use

0010

820.0 - 960.0 MHz band (LO divider = 4)

0011

Not in use

0100

410.0 - 480.0 MHz band (LO divider = 8)

0101

Not in use

0110

273.3 - 320.0 MHz band (LO divider = 12)

0111

Not in use

1000
1001

205.0 - 240.0 MHz band (LO divider = 16)
Not in use

1010

164.0 - 192.0 MHz band (LO divider = 20)

1011

136.7 - 160.0 MHz band (LO divider = 24)

1100 1111

Not in use

SWRU346B

Page 91 of 114

CC120X
WOR_CFG1 - eWOR Configuration Reg. 1
Bit #

Name

Reset

R/W

Description

7:6

WOR_RES

0x00

R/W

eWOR timer resolution. Controls the tEvent0 and RX timeout resolution

1
EVENT 0 2 5* WOR _ RES [s]
f RCOSC

t Event 0
and

RX Timeout

5:3

2:0

WOR_MODE

EVENT1

0x01

0x00

R/W

MAX 1, FLOOR

EVENT 0
2 RFEND_CFG1.RX_TIME

High resolution

Medium high resolution

Medium low resolution

Low resolution

2 4 WOR _ RES

1250
[s]
f XOSC

eWOR mode
000

Feedback mode

001

Normal mode

010

Legacy mode

011

Event1 mask mode

100

Event0 mask mode

101 - 111

Reserved

Event 1 timeout

t Event 1

1
WOR _ EVENT1[s]
f RCOSC

EVENT1

WOR_EVENT1

000

001

010

011

100

101

110

111

WOR_CFG0 - eWOR Configuration Reg. 0
Bit #

Name

Reset

R/W

Description

7:6

RX_DUTY_CYCLE_MODE

0x00

RX duty cycle mode configuration. eWOR mode and RXDCM cannot be enabled
at the same time. Both modes can be used in RX Sniff mode implementation

4:3

DIV_256HZ_EN

EVENT2_CFG

0x01

0x00

R/W

RXDCM disabled

RXDCM 0

RXDCM 1

RXDCM 2

Clock division enable. Enables clock division in SLEEP mode
0

Clock division disabled

Clock division enabled

Setting DIV_256HZ_EN = 1 will lower the current consumption in SLEEP mode.
Note that when this bit is set the radio should not be woken from SLEEP by
pulling CSn low.
Event 2 timeout

t Event 2

2:1

RC_MODE

0x00

R/W

2WOR _ EVENT 2
[s]
f RCOSC

EVENT2_CFG

WOR_EVENT2

00
01

Disabled
15

RCOSC calibration mode. Configures when the RCOSC calibration sequence is
performed. If calibration is enabled, WOR_CFG0.RC_PD must be 0
00

RCOSC calibration disabled

RCOSC calibration enabled

RCOSC calibration is enabled on every 4th time the device is
powered up and goes from IDLE to RX. This setting should only
be used together with eWOR
RCOSC power down signal
11

RC_PD

0x01

R/W

RCOSC is running

RCOSC is in power down

SWRU346B

Page 92 of 114

CC120X
WOR_EVENT0_MSB - Event 0 Configuration MSB
Bit #

Name

Reset

R/W

Description

7:0

EVENT0_15_8

0x00

R/W

Event 0 timeout (MSB)

t Event 0

1
EVENT 0 2 5* WOR_CFG1.W OR_RES [s]
f RCOSC

WOR_EVENT0_LSB - Event 0 Configuration LSB
Bit #

Name

Reset

R/W

Description

7:0

EVENT0_7_0

0x00

R/W

Event 0 timeout (LSB). See WOR_EVENT0_MSB

RXDCM_TIME - RX Duty Cycle Mode Configuration
Bit #

Name

Reset

R/W

Description

7:0

RX_DUTY_CYCLE_TIME

0x00

R/W

Configures the time spent in RXDCM state
RX_DUTY_CYCLE_TIME = 0:

t RXDCM

2WOR_CFG1.WOR_RES[µs]

RX_DUTY_CYCLE_TIME ≠ 0:

t RXDCM

RX _ DUTY _ CYCLE _ TIME 2 WOR_CFG1.WOR_RES [µs]

PKT_CFG2 - Packet Configuration Reg. 2
Bit #

Name

Reset

R/W

PKT_CFG2_NOT_USED

0x00

BYTE_SWAP_EN

0x00

R/W

FG_MODE_EN

0x00

R/W

Description
TX/RX data byte swap enable. In RX, all bits in the received data byte are
swapped before written to the RX FIFO. In TX, all bits in the TX FIFO data byte
are swapped before being transmitted
0

Data byte swap disabled

Data byte swap enabled

Select between standard packet mode or 802.15.4g packet mode
0
Standard packet mode enabled
1

4:2

CCA_MODE

0x01

R/W

802.15.4g packet mode enabled (will override other packet engine
configuration settings)
CCA mode. Selects the definition of a clear channel (when to assert the CCA
signal)
000
Always give a clear channel indication
001

Indicates clear channel when RSSI is below threshold

010

Indicates clear channel unless currently receiving a packet

011

Indicates clear channel when RSSI is below threshold and currently
not receiving a packet
Indicates clear channel when RSSI is below threshold and ETSI
LBT requirements are met
Reserved

100
101 - 111
1:0

PKT_FORMAT

0x00

R/W

Packet format configuration
00

Normal mode/FIFO mode (MDMCFG1.FIFO_EN must be set to 1
and MDMCFG0.TRANSPARENT_MODE_EN must be set to 0)

Synchronous serial mode (MDMCFG1.FIFO_EN must be set to 0 and
MDMCFG0.TRANSPARENT_MODE_EN must be set to 0). This mode
is only supported for 2’ary modulations formats in TX. In RX, both
2’ary and 4’ary modulation formats are supported

Random mode. Send random data using PN9 generator (Set
TXLAST != TXFIRST before strobing STX)

Transparent serial mode (MDMCFG1.FIFO_EN must be set to 0 and
MDMCFG0.TRANSPARENT_MODE_EN must be set to 1). This mode is
only supported for 2’ary modulations formats.

SWRU346B

Page 93 of 114

CC120X
PKT_CFG1 - Packet Configuration Reg. 1
Bit #

Name

Reset

R/W

Description

FEC_EN

0x00

R/W

Forward error correction enable
0

4:3

2:1

WHITE_DATA

PN9_SWAP_EN

ADDR_CHECK_CFG

CRC_CFG

APPEND_STATUS

0x00

0x01

R/W

FEC disabled

1
FEC enabled
Whitening enable
0

Data whitening disabled

Data whitening enabled

PN9 sequence swap enable Determines if the PN9 sequence is swapped prior to
whitening/de-whitening. This settings is only used when WHITE_DATA = 1 and
PKT_CFG2.FG_MODE_EN = 0
0

PN9 sequence swap disabled

PN9 sequence swap enabled

Address check configuration. Controls how address check is performed in RX
mode
00
No address check
01

Address check, no broadcast

Address check, 0x00 broadcast

Address check, 0x00 and 0xFF broadcast

CRC configuration
00

CRC disabled for TX and RX

CRC calculation in TX mode and CRC check in RX mode enabled.
CRC16(X16+X15+X2+1). Initialized to 0xFFFF

CRC calculation in TX mode and CRC check in RX mode enabled.
CRC16(X16+X12+X5+1). Initialized to 0x0000

CRC calculation in TX mode and CRC check in RX mode enabled. 1's
complement of CRC16(X16+X12+X5+1). Initialized to 0x1D0F

Append status bytes to RX FIFO. The status bytes contain info about CRC, RSSI,
and LQI. When CRC_CFG = 0, the CRC_OK field in the status byte will be 0
0

Status byte not appended

Status byte appended

PKT_CFG0 - Packet Configuration Reg. 0
Bit #

Name

Reset

R/W

Description

7
6:5

PKT_CFG0_RESERVED7
LENGTH_CONFIG

0x00
0x00

R/W
R/W

Packet length configuration
00

Fixed packet length mode. Packet length configured through the PKT_LEN
register

Variable packet length mode. Packet length configured by the first byte
received after sync word
Infinite packet length mode

10
11
4:2

PKT_BIT_LEN

0x00

R/W

UART_MODE_EN

0x00

R/W

UART_SWAP_EN

0x00

R/W

Variable packet length mode. Length configured by the 5 LSB of the first
byte received after sync word
In fixed packet length mode this field (when not zero) indicates the number of bits
to send/receive after PKT_LEN number of bytes are sent/received. CRC is not
supported when PKT_LEN_BIT ≠ 0
UART mode enable. When enabled, the packet engine will insert/remove a start
and stop bit to/from the transmitted/received bytes
0

UART mode disabled

UART mode enabled

Swap start and stop bits values
0
Swap disabled. Start/stop bits values are '1'/'0'
1

Swap enabled. Start/stop bits values are '0'/'1'

SWRU346B

Page 94 of 114

CC120X
RFEND_CFG1 - RFEND Configuration Reg. 1
Bit #

Name

Reset

R/W

7:6

RFEND_CFG1_NOT_USED

0x00

5:4

RXOFF_MODE

0x00

R/W

3:1

RX_TIME

0x07

R/W

Description
RXOFF mode. Determines the state the radio will enter after receiving a good
packet
00

IDLE

FSTXON

RX timeout for sync word search in RX

RX Timeout

MAX 1, FLOOR

EVENT 0
2 RX _ TIME 3

24 WOR_CFG1.WOR_RES

1250
[s]
f XOSC

The RX timeout is disabled when RX_TIME = 111b
EVENT0 is found in the WOR_EVENT0_MSB and WOR_EVENT0_LSB registers
0

RX_TIME_QUAL

0x01

R/W

RX timeout qualifier
0

Continue RX mode on RX timeout if sync word is found

Continue RX mode on RX timeout if sync word has been found, or if
PQT is reached or CS is asserted

RFEND_ CFG0 - RFEND Configuration Reg. 0
Bit #

Name

Reset

R/W

RFEND_CFG0_NOT_USED

0x00

CAL_END_WAKE_UP_EN

0x00

R/W

5:4

TXOFF_MODE

TERM_ON_BAD_PACKET_EN

0x00

R/W

Description
Enable additional wake-up pulses on the end of calibration. To be used
together with the MCU_WAKEUP signal (MARC_STATUS_OUT will be 0)
0

Disable additional wake-up pulse

Enable additional wake-up pulse

TXOFF mode. Determines the state the radio will enter after transmitting a
packet
00
IDLE
01

FSTXON

Terminate on bad packet enable
0

Terminate on bad packet disabled. When a bad packet is received
(address, length, or CRC error) the radio stays in RX regardless of
the RFEND_CFG1.RXOFF_MODE

Terminate on bad packet enabled. RFEND_CFG1.RXOFF_MODE is
ignored and the radio enters IDLE mode (or SLEEP mode if eWOR
is used) when a bad packet has been received
Direct RX termination and antenna diversity configuration
1

2:0

ANT_DIV_RX_TERM_CFG

0x00

R/W

000

Antenna diversity and termination based on CS/PQT are disabled

001

RX termination based on CS is enabled (Antenna diversity OFF)

010

Single-switch antenna diversity on CS enabled. One or both
antenna is CS evaluated once and RX will terminate if CS failed on
both antennas
Continuous-switch antenna diversity on CS enabled. Antennas are
switched until CS is asserted or RX timeout occurs (if RX timeout is
enabled)
RX termination based on PQT is enabled (Antenna diversity OFF).
MDMCFG1.CARRIER_SENSE_GATE must be 0 when this feature is
used

011

100

101

Single-switch antenna diversity on PQT enabled. One or both
antennas are PQT evaluated once and RX will terminate if PQT is
not reached on any of the antennas.
MDMCFG1.CARRIER_SENSE_GATE must be 0 when this feature is
used

110

Continuous-switch antenna diversity on PQT enabled. Antennas are
switched until PQT is reached or RX timeout occurs (if RX timeout is
enabled). MDMCFG1.CARRIER_SENSE_GATE must be 0 when this
feature is used
Reserved

111

SWRU346B

Page 95 of 114

CC120X
PA_CFG1 - Power Amplifier Configuration Reg. 1
Bit #

Name

Reset

R/W

PA_CFG1_NOT_USED

0x00

R/W

PA_RAMP_SHAPE_EN

0x01

R/W

Description
PA ramping and ASK/OOK shaping enable
0
1

5:0

PA_POWER_RAMP

0x3F

R/W

PA ramping and ASK/OOK shaping disabled
PA ramping and ASK/OOK shaping enabled

PA power ramp target level

Output Power

PA _ POWER _ RAMP 1
18 [dBm]
2

PA_POWER_RAMP >= 0x03 for the equation to be valid. {0x00, 0x01, 0x02} are
special power levels

PA_CFG0 - Power Amplifier Configuration Reg. 0
Bit #

Name

Reset

R/W

Description

7:5

FIRST_IPL

0x02

R/W

First intermediate power level. The first intermediate power level can be
programmed within the power level range 0 - 7/16 in steps of 1/16

4:2

SECOND_IPL

0x05

R/W

Second intermediate power level. The second intermediate power level can be
programmed within the power level range 8/16 - 15/16 in steps of 1/16

1:0

RAMP_SHAPE

0x02

R/W

PA ramp time and ASK/OOK shape length. Note that only certain values of
MDMCFG2.UPSAMPLER_P complies with the different ASK/OOK shape lengths
00

3/8 symbol ramp time and 1/32 symbol ASK/OOK shape length
(legal UPSAMPLER_P values: 100b, 101b, and 110b)

3/2 symbol ramp time and 1/16 symbol ASK/OOK shape length
(legal UPSAMPLER_P values: 011b, 100b, 101b, and 110b)

3 symbol ramp time and 1/8 symbol ASK/OOK shape length
(legal UPSAMPLER_P values: 010b, 011b, 100b, 101b, and 110b)

6 symbol ramp time and 1/4 symbol ASK/OOK shape length
(legal UPSAMPLER_P values: 010b , 010b, 011b, 100b, 101b,
and 110b )

ASK_CFG - ASK Configuration
Bit #

Name

Reset

R/W

Description

7:6

AGC_ASK_BW

0x00

R/W

Controls the bandwidth of the data filter in ASK/OOK mode. The -3 dB cut-off
frequency (fCut-Off) is given below
RX_CONFIG_LIMITATION = 0:

fCut

Off

4 ASK BW Scale Factor RX Filter BW [Hz]

RX_CONFIG_LIMITATION = 1:

fCut

Off

8 ASK BW Scale Factor RX Filter BW [Hz]

RX_CONFIG_LIMITATION is found in SYNC_CFG0
A rule of thumb is to set fCut-Off ≥ 5∙symbol rate

5:0

ASK_DEPTH

0x0F

R/W

00
01

ASK BW scale factor = 0.28
ASK BW scale factor = 0.18

ASK BW scale factor = 0.15

ASK BW scale factor = 0.14

ASK/OOK depth

AMAX
AMIN

( PA _ CFG1.PA _ POWER _ RAMP 1)
18 [dBm]
2
( PA _ CFG1.PA _ POWER _ RAMP 1 ASK _ DEPTH )
18 [dBm]
2

Minimum PA power level is -16 dBm. PA_POWER_RAMP - ASK_DEPTH = 0x00 is
OOK off state (< −50 dBm)

PKT_LEN - Packet Length Configuration
Bit #

Name

Reset

R/W

Description

7:0

PACKET_LENGTH

0x00

R/W

In fixed length mode this field indicates the packet length, and a value of 0 indicates
the length to be 256 bytes. In variable length packet mode, this value indicates the
maximum allowed length packets

SWRU346B

Page 96 of 114

CC120X
IF_MIX_CFG - IF Mix Configuration
Bit #

Name

Reset

R/W

7:5

IF_MIX_CFG_NOT_USED

0x00

4:2

CMIX_CFG

0x00

R/W

Description
Intermediate frequency configuration. The decimation factor is given by
CHAN_BW.ADC_CIC_DECFACT
000
001

010

011

100
101

110

111

1:0

IF_MIX_CFG_RESERVED1_0

0x00

R/W

Zero-IF

f IF
f IF
f IF

f xosc
[kHz]
Decimation Factor 4
f xosc
[kHz]
Decimation Factor 6
f xosc
[kHz]
Decimation Factor 8

Zero-IF

f IF
f IF
f IF

f xosc
[kHz]
Decimation Factor 4
f xosc
[kHz]
Decimation Factor 6
f xosc
[kHz]
Decimation Factor 8

For test purposes only, use values from SmartRF Studio

FREQOFF_CFG - Frequency Offset Correction Configuration
Bit #

Name

Reset

R/W

7:6

FREQOFF_CFG_NOT_USED

0x00

FOC_EN

0x01

R/W

4:3

1:0

FOC_CFG

FOC_LIMIT

FOC_KI_FACTOR

0x00

R/W

Description
Frequency offset correction enable
0

Frequency offset correction disabled

Frequency offset correction enabled

Frequency offset correction configuration. FOC_CFG ≠ 0 enables a narrower
RX filter BW than FOC_CFG = 0 but needs longer settle time. When FOC in FS
is enabled, the device automatically switch to 'FOC after channel filter' when a
sync word is detected
00

FOC after channel filter (typical 0 - 1 preamble bytes for settling)

FOC in FS enabled. Loop gain factor is 1/128 (typical 2 - 4 preamble
bytes for settling)

FOC in FS enabled. Loop gain factor is 1/256 (typical 2 - 4 preamble
bytes for settling)

FOC in FS enabled. Loop gain factor is 1/512 (typical 2 - 4 preamble
bytes for settling)

FOC limit. This is the maximum frequency offset correction in the frequency
synthesizer. Only valid when FOC_CFG ≠ 0
0

RX filter bandwidth/4

RX filter bandwidth/8

Frequency offset correction.
MDMCFG0.TRANSPARENT_MODE_EN | FOC_KI_FACTOR
000

100

Frequency offset compensation disabled after sync detected (typical
setting for short packets)
Frequency offset compensation during packet reception with loop gain
factor = 1/32 (fast loop)
Frequency offset compensation during packet reception with loop gain
factor = 1/64
Frequency offset compensation during packet reception with loop gain
factor = 1/128 (slow loop)
Frequency offset compensation with loop gain factor 1/128 (fast loop)

101

Frequency offset compensation with loop gain factor 1/256

110

Frequency offset compensation with loop gain factor 1/512

111

Frequency offset compensation with loop gain factor 1/1024 (slow
loop)

001
010
011

SWRU346B

Page 97 of 114

CC120X
TOC_CFG - Timing Offset Correction Configuration
Bit #

Name

Reset

R/W

Description

7:6

TOC_LIMIT

0x00

R/W

Timing offset correction limit. TOC_LIMIT specifies maximum symbol rate
offset the receiver is able to handle. TOC_LIMIT ≠ 0 requires 2 - 4 bytes
preamble for symbol rate offset compensation

5:3

TOC_PRE_SYNC_BLOCKLEN

0x01

R/W

< 0.2 %

< 2 % ppm

Reserved

< 12 % ppm (MDMCFG1.CARRIER_SENSE_GATE
must be set)

When TOC_LIMIT = 0 the receiver uses a block based time offset error
calculation algorithm where the block length is configurable through register
TOC_CFG. Before a sync word is found (SYNC_EVENT is asserted) the
TOC_PRE_SYNC_BLOCKLEN sets the actual block length used for the time
offset algorithm
000

8 symbols integration window

001
010

16 symbols integration window
32 symbols integration window

011

64 symbols integration window

100

128 symbols integration window

101

256 symbols integration window

110

Reserved

111

Reserved

If TOC_LIMIT ≠ 0: Symbol by symbol timing error proportional scale factor

2:0

TOC_POST_SYNC_BLOCKLEN

0x03

R/W

000

Proportional scale factor = 8/16

001

Proportional scale factor = 6/16

010

Proportional scale factor = 2/16

011

Proportional scale factor = 1/16

1xx

Proportional scale factor = 1/16 after sync found

When TOC_LIMIT = 0 the receiver uses a block based time offset error
calculation algorithm where the block length is configurable through register
TOC_CFG. After a sync word is found (SYNC_EVENT is asserted) the
TOC_POST_SYNC_BLOCKLEN sets the actual block length used for the time
offset algorithm
000
8 symbols integration window
001

16 symbols integration window

010

32 symbols integration window

011

64 symbols integration window

100

128 symbols integration window

101

256 symbols integration window

110

Reserved

111

Reserved

If TOC_LIMIT ≠ 0: Symbol by symbol timing error proportional scale factor
000

Freeze integral value

001
010

Integral scale factor = 6/32
Integral scale factor = 2/32

011

Integral scale factor = 1/32

1xx

Integral scale factor = 1/32 after sync found

MARC_SPARE - MARC Spare
Bit #

Name

Reset

R/W

7:4

MARC_SPARE_NOT_USED

0x00

3:0

AES_COMMANDS

0x00

R/W

Description
High level commands used to accelerate AES operations on the FIFO
content
0000 - 1000

Reserved

1001

AES_TXFIFO

1010

AES_RXFIFO

1011 - 1111

Reserved

SWRU346B

Page 98 of 114

CC120X
ECG_CFG - External Clock Frequency Configuration
Bit #

Name

Reset

R/W

7:5

ECG_CFG_NOT_USED

0x00

4:0

EXT_CLOCK_FREQ

0x00

R/W

Description
External clock frequency. Controls the division factor
00000
00001

64
62

00010

00011

00100

00101

00110

00111

01000

01001

01010

01011
01100

42
40

01101

01110

01111

10000

10001

10010

10011

10100

10101

10110

10111
11000

18
16

11001

11010

11011

11100

11101

11110

11111

EXT_CTRL - External Control Configuration
Bit #

Name

Reset

R/W

7:3

EXT_CTRL_NOT_USED

0x00

PIN_CTRL_EN

0x00

R/W

EXT_40K_CLOCK_EN

0x00

R/W

Description
Pin control enable. Pin control reuses the SPI interface pins to execute SRX,
STX, SPWD, and IDLE strobes
0

Pin control disabled

Pin control enabled

External 40k clock enable
0
1

BURST_ADDR_INCR_EN

0x01

R/W

External 40k clock disabled
External 40k clock enabled. IOCFG3.GPIO3_CFG must be set to
HIGHZ (EXT_40K_CLOCK)

Burst address increment enable
0

Burst address increment disabled (i.e. consecutive writes to the
same address location in burst mode)

Burst address increment enabled (i.e. the address is incremented
during burst access)

RCCAL_FINE - RC Oscillator Calibration Fine
Bit #

Name

Reset

R/W

Description

7
6:0

RCCAL_FINE_NOT_USED
RCC_FINE

0x00
0x00

R
R/W

40 kHz RCOSC calibrated fine value

RCCAL_COURSE - RC Oscillator Calibration Course
Bit #

Name

Reset

R/W

RCCAL_COURSE_NOT_USED

0x00

6:0

RCC_ COURSE

0x00

R/W

Description
40 kHz RCOSC calibrated course value

SWRU346B

Page 99 of 114

CC120X
RCCAL_OFFSET - RC Oscillator Calibration Clock Offset
Bit #

Name

Reset

R/W

7:5

RCCAL_OFFSET_NOT_USED

0x00

Description

4:0

RCCAL_OFFSET_RESERVED4_0

0x00

R/W

For test purposes only, use values from SmartRF Studio

FREQOFF1 - Frequency Offset MSB
Bit #

Name

Reset

R/W

Description

7:0

FREQ_OFF_15_8

0x00

R/W

Frequency offset [15:8]. Updated by user or SAFC strobe. The value is in
two's complement format

FREQOFF0 - Frequency Offset LSB
Bit #

Name

Reset

R/W

Description

7:0

FREQ_OFF_7_0

0x00

R/W

Frequency offset [7:0]. Updated by user or SAFC strobe. The value is in
two's complement format

FREQ2 - Frequency Configuration [23:16]
Bit #

Name

Reset

R/W

Description

7:0

FREQ_23_16

0x00

R/W

Frequency [23:16]

f RF

fVCO
[Hz]
LO Divider

where

fVCO

FREQ
f XOSC
216

FREQOFF
f XOSC [Hz]
218

and the LO Divider is given by FS_CFG.FSD_BANDSELECT

FREQ1 - Frequency Configuration [15:8]
Bit #

Name

Reset

R/W

Description

7:0

FREQ_15_8

0x00

R/W

Frequency [15:8]. See FREQ2

FREQ0 - Frequency Configuration [7:0]
Bit #

Name

Reset

R/W

Description

7:0

FREQ_7_0

0x00

R/W

Frequency [7:0]. See FREQ2

IF_ADC2 - Analog to Digital Converter Configuration Reg. 2
Bit #

Name

Reset

R/W

7:4

IF_ADC2_NOT_USED

0x00

3:0

IF_ADC2_RESERVED3_0

0x02

R/W

Description
For test purposes only, use values from SmartRF Studio

IF_ADC1 - Analog to Digital Converter Configuration Reg. 1
Bit #

Name

Reset

R/W

Description

7:0

IF_ADC1_RESERVED7_0

0x5A

R/W

For test purposes only, use values from SmartRF Studio

IF_ADC0 - Analog to Digital Converter Configuration Reg. 0
Bit #

Name

Reset

R/W

7:6

IF_ADC0_NOT_USED

0x00

5:0

IF_ADC0_RESERVED5_0

0x1A

R/W

Description
For test purposes only, use values from SmartRF Studio

FS_DIG1 - Frequency Synthesizer Digital Reg. 1
Bit #

Name

Reset

R/W

Description

7:6
5:0

FS_DIG1_NOT_USED
FS_DIG1_RESERVED5_0

0x00
0x08

R
R/W

For test purposes only, use values from SmartRF Studio

SWRU346B

Page 100 of 114

CC120X
FS_DIG0 - Frequency Synthesizer Digital Reg. 0
Bit #

Name

Reset

R/W

Description

7:4

FS_DIG0_RESERVED7_4

0x05

R/W

For test purposes only, use values from SmartRF Studio

3:2

RX_LPF_BW

0x02

R/W

FS loop bandwidth in RX

1:0

TX_LPF_BW

0x02

R/W

00
01

200 kHz
300 kHz

400 kHz

500 kHz

FS loop bandwidth in TX
00

200 kHz

300 kHz

400 kHz

500 kHz

FS_CAL3 - Frequency Synthesizer Calibration Reg. 3
Bit #

Name

Reset

R/W

Description

FS_CAL3_ RESERVED7

0x00

For test purposes only, use values from SmartRF Studio

KVCO_HIGH_RES_CFG

0x00

R/W

KVCO high resolution enable
0
High resolution disabled (normal resolution mode)
1

5:0

FS_CAL3_RESERVED5_0

0x00

R/W

High resolution enabled (increased charge pump calibration, but will
extend the calibration time)
For test purposes only, use values from SmartRF Studio

FS_CAL2 - Frequency Synthesizer Calibration Reg. 2
Bit #

Name

Reset

R/W

7:6

FS_CAL2_NOT_USED

0x00

5:0

FS_CAL2_RESERVED5_0

0x20

R/W

Description
For test purposes only, use values from SmartRF Studio

FS_CAL1 - Frequency Synthesizer Calibration Reg. 1
Bit #

Name

Reset

R/W

Description

7:0

FS_CAL1_RESERVED7_0

0x00

R/W

For test purposes only, use values from SmartRF Studio

FS_CAL0 - Frequency Synthesizer Calibration Reg. 0
Bit #

Name

Reset

R/W

7:4

FS_CAL0_NOT_USED

0x00

3:2

LOCK_CFG

0x00

R/W

1:0

FS_CAL0_RESERVED1_0

0x00

R/W

Description
Out of lock detector average time
00

Average the measurement over 512 cycles

Average the measurement over 1024 cycles

Average the measurement over 256 cycles

Infinite average

For test purposes only, use values from SmartRF Studio

FS_CHP - Frequency Synthesizer Charge Pump Configuration
Bit #

Name

Reset

R/W

7:6

FS_CHP_NOT_USED

0x00

5:0

FS_CHP_RESERVED5_0

0x28

R/W

Description
For test purposes only, use values from SmartRF Studio

FS_DIVTWO - Frequency Synthesizer Divide by 2
Bit #

Name

Reset

R/W

7:2

FS_DIVTWO_NOT_USED

0x00

1:0

FS_DIVTWO_RESERVED1_0

0x01

R/W

Description
For test purposes only, use values from SmartRF Studio

FS_DSM1 - FS Digital Synthesizer Module Configuration Reg. 1
Bit #

Name

Reset

R/W

7:3

FS_DSM1_NOT_USED

0x00

2:0

FS_DSM1_RESERVED2_0

0x00

R/W

Description
For test purposes only, use values from SmartRF Studio

FS_DSM0 - FS Digital Synthesizer Module Configuration Reg. 0
Bit #

Name

Reset

R/W

Description

7:0

FS_DSM0_RESERVED7_0

0x03

R/W

For test purposes only, use values from SmartRF Studio

FS_DVC1 - Frequency Synthesizer Divider Chain Configuration Reg. 1
Bit #

Name

Reset

R/W

Description

7:0

FS_DVC1_RESERVED7_0

0xFF

R/W

For test purposes only, use values from SmartRF Studio

SWRU346B

Page 101 of 114

CC120X
FS_DVC0 - Frequency Synthesizer Divider Chain Configuration Reg. 0
Bit #

Name

Reset

R/W

7:5

FS_DVC0_NOT_USED

0x00

4:0

FS_DVC0_RESERVED4_0

0x1F

R/W

Description
For test purposes only, use values from SmartRF Studio

FS_LBI - Frequency Synthesizer Local Bias Configuration
Bit #

Name

Reset

R/W

7:0

FS_LBI_NOT_USED

0x00

Description

FS_PFD - Frequency Synthesizer Phase Frequency Detector Configuration
Bit #

Name

Reset

R/W

FSD_PFD_NOT_USED

0x00

6:0

FS_PFD_RESERVED6_0

0x51

R/W

Description
For test purposes only, use values from SmartRF Studio

FS_PRE - Frequency Synthesizer Prescaler Configuration
Bit #

Name

Reset

R/W

FS_PRE_NOT_USED

0x00

6:0

FS_PRE_RESERVED6_0

0x2C

R/W

Description
For test purposes only, use values from SmartRF Studio

FS_REG_DIV_CML - Frequency Synthesizer Divider Regulator Configuration
Bit #

Name

Reset

R/W

7:5

FS_REG_DIV_CML_NOT_USED

0x00

4:0

FS_REG_DIV_CML_RESERVED4_0

0x11

R/W

Description
For test purposes only, use values from SmartRF Studio

FS_SPARE - Frequency Synthesizer Spare
Bit #

Name

Reset

R/W

Description

7:0

FS_SPARE_RESERVED7_0

0x00

R/W

For test purposes only, use values from SmartRF Studio

FS_VCO4 - FS Voltage Controlled Oscillator Configuration Reg. 4
Bit #

Name

Reset

R/W

7:5

FS_VCO4_NOT_USED

0x00

4:0

FS_VCO4_RESERVED4_0

0x14

R/W

Description
For test purposes only, use values from SmartRF Studio

FS_VCO3 - FS Voltage Controlled Oscillator Configuration Reg. 3
Bit #

Name

Reset

R/W

7:1

FS_VCO3_NOT_USED

0x00

FS_VCO3_RESERVED0

0x00

R/W

Description
For test purposes only, use values from SmartRF Studio

FS_VCO2 - FS Voltage Controlled Oscillator Configuration Reg. 2
Bit #

Name

Reset

R/W

FS_VCO2_NOT_USED

0x00

6:0

FS_VCO2_RESERVED6_0

0x00

R/W

Description
For test purposes only, use values from SmartRF Studio

FS_VCO1 - FS Voltage Controlled Oscillator Configuration Reg. 1
Bit #

Name

Reset

R/W

7:2

FSD_VCDAC

0x00

R/W

1:0

FS_VCO1_RESERVED1_0

0x00

R/W

Description
For test purposes only, use values from SmartRF Studio

FS_VCO0 - FS Voltage Controlled Oscillator Configuration Reg. 0
Bit #

Name

Reset

R/W

Description

7:0

FS_VCO0_RESERVED7_0

0x81

R/W

For test purposes only, use values from SmartRF Studio

GBIAS6 - Global Bias Configuration Reg. 6
Bit #

Name

Reset

R/W

7:6

GBIAS6_NOT_USED

0x00

5:0

GBIAS6_RESERVED5_0

0x00

R/W

Description
For test purposes only, use values from SmartRF Studio

GBIAS5 - Global Bias Configuration Reg. 5
Bit #

Name

Reset

R/W

7:4

GBIAS5_NOT_USED

0x00

3:0

GBIAS5_RESERVED3_0

0x02

R/W

Description
For test purposes only, use values from SmartRF Studio

GBIAS4 - Global Bias Configuration Reg. 4
Bit #

Name

Reset

R/W

7:6

GBIAS4_NOT_USED

0x00

5:0

GBIAS4_RESERVED5_0

0x00

R/W

Description
For test purposes only, use values from SmartRF Studio

SWRU346B

Page 102 of 114

CC120X
GBIAS3 - Global Bias Configuration Reg. 3
Bit #

Name

Reset

R/W

7:6

GBIAS3_NOT_USED

0x00

5:0

GBIAS3_RESERVED5_0

0x00

R/W

Description
For test purposes only, use values from SmartRF Studio

GBIAS2 - Global Bias Configuration Reg. 2
Bit #

Name

Reset

R/W

GBIAS2_NOT_USED

0x00

6:0

GBIAS2_RESERVED6_0

0x10

R/W

Description
For test purposes only, use values from SmartRF Studio

GBIAS1 - Global Bias Configuration Reg. 1
Bit #

Name

Reset

R/W

7:5

GBIAS1_NOT_USED

0x00

4:0

GBIAS1_RESERVED4_0

0x00

R/W

Description
For test purposes only, use values from SmartRF Studio

GBIAS0 - Global Bias Configuration Reg. 0
Bit #

Name

Reset

R/W

7:2

GBIAS0_NOT_USED

0x00

1:0

GBIAS0_RESERVED1_0

0x00

R/W

Description
For test purposes only, use values from SmartRF Studio

IFAMP - Intermediate Frequency Amplifier Configuration
Bit #

Name

Reset

R/W

7:4

IFAMP_NOT_USED

0x00

3:2

IFAMP_BW

0x00

R/W

Description
Single side bandwidth control bits covering frequency range from 300 kHz to
1500 kHz.

Single Side BW

1:0

IFAMP_RESERVED1_0

0x01

R/W

300 kHz

600 kHz

1000 kHz

1500 kHz

f IF

RX Filter BW
2

For test purposes only, use values from SmartRF Studio

LNA - Low Noise Amplifier Configuration
Bit #

Name

Reset

R/W

7:2

LNA_NOT_USED

0x00

Description

1:0

LNA_RESERVED1_0

0x01

R/W

For test purposes only, use values from SmartRF Studio

Description

RXMIX - RX Mixer Configuration
Bit #

Name

Reset

R/W

7:2

RXMIX_NOT_USED

0x00

1:0

RXMIX_RESERVED1_0

0x01

R/W

For test purposes only, use values from SmartRF Studio

XOSC5 - Crystal Oscillator Configuration Reg. 5
Bit #

Name

Reset

R/W

7:4

XOSC5_NOT_USED

0x00

3:0

XOSC5_RESERVED3_0

0x0C

R/W

Description
For test purposes only, use values from SmartRF Studio

XOSC4 - Crystal Oscillator Configuration Reg. 4
Bit #

Name

Reset

R/W

Description

7:0

XOSC4_RESERVED7_0

0xA0

R/W

For test purposes only, use values from SmartRF Studio

XOSC3 - Crystal Oscillator Configuration Reg. 3
Bit #

Name

Reset

R/W

Description

7:0

XOSC3_RESERVED7_0

0x03

R/W

For test purposes only, use values from SmartRF Studio

XOSC2 - Crystal Oscillator Configuration Reg. 2
Bit #

Name

Reset

R/W

7:4

XOSC2_NOT_USED

0x00

Description

3:1

XOSC2_RESERVED3_1

0x02

R/W

For test purposes only, use values from SmartRF Studio

XOSC_CORE_PD_OVERRIDE

0x00

R/W

XOSC core power down override
0

The XOSC will be turned off if the SXOFF, SPWD, or SWOR command
strobes are issued

The XOSC is forced on even if an SXOFF, SPWD, or SWOR command
strobe has been issued. This can be used to enable fast start-up from
SLEEP/XOFF on the expense of a higher current consumption

SWRU346B

Page 103 of 114

CC120X
XOSC1 - Crystal Oscillator Configuration Reg. 1
Bit #

Name

Reset

R/W

7:3

XOSC1_NOT_USED

0x00

Description

XOSC1_RESERVED2

0x00

R/W

For test purposes only, use values from SmartRF Studio

XOSC_BUF_SEL

0x00

R/W

XOSC buffer select. Selects internal XOSC buffer for RF PLL
0

Low power, single ended buffer (differential buffer is shut down)

1
0

XOSC_STABLE

0x01

Low phase noise, differential buffer (low power buffer still used for
digital clock)
XOSC is stable (has finished settling)

XOSC0 - Crystal Oscillator Configuration Reg. 0
Bit #

Name

Reset

R/W

7:2

XOSC0_NOT_USED

0x00

Description

1:0

XOSC0_RESERVED1_0

0x00

For test purposes only, use values from SmartRF Studio

ANALOG_SPARE - Analog Spare
Bit #

Name

Reset

R/W

Description

7:0

ANALOG_SPARE_RESERVED7_0

0x00

R/W

For test purposes only, use values from SmartRF Studio

PA_CFG3 - Power Amplifier Configuration Reg. 3
Bit #

Name

Reset

R/W

7:3

PA_CFG3_NOT_USED

0x00

2:0

PA_CFG3_RESERVED2_0

0x00

R/W

Description
For test purposes only, use values from SmartRF Studio

WOR_TIME1 - eWOR Timer Counter Value MSB
Bit #

Name

Reset

R/W

Description

7:0

WOR_STATUS_15_8

0x00

eWOR timer counter value [15:8]

WOR_TIME0 - eWOR Timer Counter Value LSB
Bit #

Name

Reset

R/W

Description

7:0

WOR_STATUS_7_0

0x00

eWOR timer counter value [7:0]

WOR_CAPTURE1 - eWOR Timer Capture Value MSB
Bit #

Name

Reset

R/W

Description

7:0

WOR_CAPTURE_15_8

0x00

eWOR timer capture value [15:8]. Capture timer value on sync detect to
simplify timer re-synchronization

WOR_CAPTURE0 - eWOR Timer Capture Value LSB
Bit #

Name

Reset

R/W

Description

7:0

WOR_CAPTURE_7_0

0x00

eWOR timer capture value [7:0]. Capture timer value on sync detect to
simplify timer re-synchronization

Description

BIST - MARC Built-In Self-Test
Bit #

Name

Reset

R/W

7:4

BIST_NOT_USED

0x00

3:0

BIST_RESERVED3_0

0x00

R/W

For test purposes only, use values from SmartRF Studio

DCFILTOFFSET_I1 - DC Filter Offset I MSB
Bit #

Name

Reset

R/W

Description

7:0

DCFILT_OFFSET_I_15_8

0x00

R/W

DC compensation, real value [15:8]

DCFILTOFFSET_I0 - DC Filter Offset I LSB
Bit #

Name

Reset

R/W

Description

7:0

DCFILT_OFFSET_I_7_0

0x00

R/W

DC compensation, real value [7:0]

DCFILTOFFSET_Q1 - DC Filter Offset Q MSB
Bit #

Name

Reset

R/W

Description

7:0

DCFILT_OFFSET_Q_15_8

0x00

R/W

DC compensation, imaginary value [15:8]

DCFILTOFFSET_Q0 - DC Filter Offset Q LSB
Bit #

Name

Reset

R/W

Description

7:0

DCFILT_OFFSET_Q_7_0

0x00

R/W

DC compensation, imaginary value [7:0]

IQIE_I1 - IQ Imbalance Value I MSB
Bit #

Name

Reset

R/W

Description

7:0

IQIE_I_15_8

0x00

R/W

IQ imbalance value, imaginary part [15:8]

SWRU346B

Page 104 of 114

CC120X
IQIE_I0 - IQ Imbalance Value I LSB
Bit #

Name

Reset

R/W

Description

7:0

IQIE_I_7_0

0x00

R/W

IQ imbalance value, imaginary part [7:0]

IQIE_Q1 - IQ Imbalance Value Q MSB
Bit #

Name

Reset

R/W

Description

7:0

IQIE_Q_15_8

0x00

R/W

IQ imbalance value, imaginary part [15:8]

IQIE_Q0 - IQ Imbalance Value Q LSB
Bit #

Name

Reset

R/W

Description

7:0

IQIE_Q_7_0

0x00

R/W

IQ imbalance value, imaginary part [7:0]

RSSI1 - Received Signal Strength Indicator Reg. 1
Bit #

Name

Reset

R/W

Description

7:0

RSSI_11_4

0x80

Received signal strength indicator. 8 MSB of RSSI[11:0]. RSSI[11:0]
is a two's complement number with 0.0625 dB resolution hence ranging
from -128 to 127 dBm. A value of -128 dBm indicates that the RSSI is
invalid. To get a correct RSSI value a calibrated RSSI offset value should
be subtracted from the value given by RSSI[11:0]. This RSSI offset
value can either be subtracted from RSSI[11:0] manually or the offset
can be written to AGC_GAIN_ADJUST.GAIN_ADJUSTMENT meaning that
RSSI[11:0] will give a correct value directly

RSSI0 - Received Signal Strength Indicator Reg. 0
Bit #

Name

Reset

R/W

RSSI0_NOT_USED

0x00

6:3

RSSI_3_0

0x00

Received signal strength indicator. 4 LSB of RSSI[11:0]. See RSSI1

CARRIER_SENSE

0x00

Carrier sense

CARRIER_SENSE_VALID

RSSI_VALID

0x00

Description

No carrier detected

Carrier detected

Carrier sense valid
0

Carrier sense not valid

Carrier sense valid

RSSI valid
0

RSSI not valid

RSSI valid

SWRU346B

Page 105 of 114

CC120X
MARCSTATE - MARC State
Bit #

Name

Reset

R/W

MARCSTATE_NOT_USED

0x00

6:5

MARC_2PIN_STATE

0x02

4:0

MARC_STATE

0x01

Description
MARC 2 pin state value

00
01

SETTLING
TX

IDLE

MARC state

MARC 2 pin state value

00000

SLEEP26

00001

IDLE

00010

XOFF

SETTLING

00011

BIAS_SETTLE_MC

SETTLING

00100

REG_SETTLE_MC

SETTLING

00101

MANCAL

SETTLING

00110

BIAS_SETTLE

SETTLING

00111
01000

REG_SETTLE
STARTCAL

SETTLING
SETTLING

01001

BWBOOST

SETTLING

01010

FS_LOCK

SETTLING

01011

IFADCON

SETTLING

01100

ENDCAL

SETTLING

01101

01110

RX_END

01111

RXDCM

10000

TXRX_SWITCH

SETTLING

10001

RX_FIFO_ERR

SETTLING

10010

FSTXON

SETTLING

10011

10100

TX_END

10101

RXTX_SWITCH

SETTLING

10110

TX_FIFO_ERR

SETTLING

10111

IFADCON_TXRX

SETTLING

11000 11111

Reserved

Depends on the GPIO pins used (see
Section 3.4)
IDLE

LQI_VAL - Link Quality Indicator Value
Bit #

Name

Reset

R/W

Description

PKT_CRC_OK

0x00

CRC OK. Asserted in RX when PKT_CFG1.CRC_CFG = 1 or 10b and a good
packet is received. This signal is always on if the radio is in TX or if the radio is in
RX and PKT_CFG1.CRC_CFG = 0. The signal is de-asserted when RX mode is
entered and PKT_CFG1.CRC_CFG ≠ 0
0
1

6:0

LQI

0x00

CRC check not ok (bit error)
CRC check ok (no bit error)

Link quality indicator. 0 when not valid. A low value indicates a better link than
what a high value does

PQT_SYNC_ERR - Preamble and Sync Word Error
Bit #

Name

Reset

R/W

Description

7:4

PQT_ERROR

0x0F

3:0

SYNC_ERROR

0x0F

Preamble qualifier value. The actual preamble qualifier value can be greater than
15 but since PQT_ERROR is only 4 bits wide PQT_ERROR = MIN[actual PQT
qualifier value] modulo 16. This means that if PQT _ERROR = 1 the actual
preamble qualifier value is either 1 or 17. When a sync word is detected
(SYNC_EVENT is asserted) the PQT_ERROR register field is not updated again
before RX mode is re-entered. As long as the radio is in RX searching for a sync
word the register field will be updated continuously
Sync word qualifier value. The actual sync word qualifier value can be greater
than 15 but since SYNC_ERROR is only 4 bits wide SYNC_ERROR = FLOOR[actual
sync word qualifier value/2] modulo 16. This means that if SYNC_ERROR = 1 the
actual sync word qualifier value is either 2, 3, 34, or 35. When a sync word is
received (SYNC_EVENT is asserted) the SYNC_ERROR register field is not updated
again before RX mode is re-entered. As long as the radio is in RX searching for a
sync word the register field will be updated continuously

Note that it is not possible to read 0 or 00010b from MARC_STATE as pulling CSn low will take the
radio to IDLE state.
SWRU346B

Page 106 of 114

CC120X
DEM_STATUS - Demodulator Status
Bit #

Name

Reset

R/W

Description

RSSI_STEP_FOUND

0x00

RSSI step found during packet reception (after the assertion of SYNC_EVENT).
The RSSI step is 10 or 16 dB and is configured through
AGC_CFG1.RSSI_STEP_THR

COLLISION_FOUND

SYNC_LOW0_HIGH1

4:1

SRO_INDICATOR

0x00

No RSSI step found during packet reception

RSSI step found during packet reception

Collision found. Asserted if a new preamble is found and the RSSI has
increased 10 or 16 dB during packet reception (depending on
AGC_CFG1.RSSI_STEP_THR).
MDMCFG1.COLLISION_DETECT_EN must be 1
0

No collision found

Collision found

DualSync detect. Only valid when SYNC_CFG1.SYNC_MODE = 111b. When
SYNC_EVENT is asserted this bit can be checked to see which sync word is
found

Sync word found = [SYNC15_8:SYNC7_0]

Sync word found = [SYNC31_24:SYNC23_16]

Symbol rate offset indicator (two’s complement).

TOC_CFG.TOC_LIMIT = 027:

Symbol Rate Offset

SRO _ INDICATOR
106 [ppm]
4 Symbols after Sync Word

TOC_CFG.TOC_LIMIT = 1:

Symbol Rate Offset

SRO _ INDICATOR
2 [%]
7

TOC_CFG.TOC_LIMIT = 3:

Symbol Rate Offset
0

IMAGE_FOUND

0x00

SRO _ INDICATOR
12 [%]
7

Image found detector
0

No image found

Image found

FREQOFF_EST1 - Frequency Offset Estimate MSB
Bit #

Name

Reset

R/W

Description

7:0

FREQOFF_EST_15_8

0x00

Frequency offset estimate [15:8] MSB

Frequency Offset Estimate

FREQOFF _ EST f XOSC
[Hz]
LO Divider 218

The value is in two's complement format. The LO divider value can be found in
FS_CFG.FSD_BANDSELECT register field

FREQOFF_EST0 - Frequency Offset Estimate LSB
Bit #

Name

Reset

R/W

Description

7:0

FREQOFF_EST_7_0

0x00

See FREOFF_EST1

AGC_GAIN3 - Automatic Gain Control Reg. 3
Bit #

Name

Reset

R/W

AGC_GAIN3_NOT_USED

0x00

6:0

AGC_FRONT_END_GAIN

0x00

Description
AGC front end gain. Actual applied gain with 1 dB resolution

AGC_GAIN2 - Automatic Gain Control Reg. 2
Bit #

Name

Reset

R/W

Description

AGC_DRIVES_FE_GAIN

0x01

R/W

Override AGC gain control

6:0

AGC_GAIN2_RESERVED6_0

0x51

R/W

AGC controls front end gain

Front end gain controlled by registers AGC_GAIN2, AGC_GAIN1, and
AGC_GAIN0

For test purposes only, use values from SmartRF Studio

AGC_GAIN1 - Automatic Gain Control Reg. 1
Bit #

Name

Reset

R/W

7:5

AGC_GAIN1_NOT_USED

0x00

4:0

AGC_GAIN1_RESERVED4_0

0x00

R/W

Description
For test purposes only, use values from SmartRF Studio

The symbol rate offset might wrap around
SWRU346B

Page 107 of 114

CC120X
AGC_GAIN0 - Automatic Gain Control Reg. 0
Bit #

Name

Reset

R/W

AGC_GAIN0_NOT_USED

0x00

6:0

AGC_GAIN0_RESERVED6_0

0x3F

R/W

Description
For test purposes only, use values from SmartRF Studio

CFM_RX_DATA_OUT - Custom Frequency Modulation RX Data
Bit #

Name

Reset

R/W

Description

7:0

CFM_RX_DATA

0x00

8-bit signed soft-decision symbol data, either from normal receiver or
transparent receiver. Can be read using burst mode to do custom
demodulation

f OFFSET

f dev CFM _ RX _ DATA
[Hz]
64

(two's complement format). fdev is the programmed frequency deviation

CFM_TX_DATA_IN - Custom Frequency Modulation TX Data
Bit #

Name

Reset

R/W

Description

7:0

CFM_TX_DATA

0x00

R/W

8-bit signed soft TX data input register for custom SW controlled
modulation. Can be accessed using burst mode to get arbitrary
modulation

f OFFSET

f dev CFM _ TX _ DATA
[Hz]
64

(two's complement format). fdev is the programmed frequency deviation

ASK_SOFT_RX_DATA - ASK Soft Decision Output
Bit #

Name

Reset

R/W

7:6

ASK_SOFT_RX_DATA_NOT_USED

0x00

5:0

ASK_SOFT

0x30

Description
The OOK/ASK receiver use a max peak magnitude tracker and low peak
magnitude tracker to estimate ASK_THRESHOLD. The ASK_THRESHOLD
is used to do hard decision of OOK/ASK symbols.
ASK_SOFT = +16 when magnitude is ≥ ASK_THRESHOLD
ASK_SOFT = -16 when magnitude is ≥ ASK_THRESHOLD

RNDGEN - Random Number Generator Value
Bit #

Name

Reset

R/W

Description

RNDGEN_EN

0x00

R/W

Random number generator enable

6:0

RNDGEN_VALUE

0x7F

Random number generator disabled

Random number generator enabled

Random number value. Number generated by 7 bit LFSR register
(X7+X6+1). Number will be further randomized when in RX by XORing
the feedback with receiver noise.

MAGN2 - Signal Magnitude after CORDIC [16]
Bit #

Name

Reset

R/W

7:1

MAGN_NOT_USED

0x00

MAGN_16

0x00

Description
Instantaneous signal magnitude after CORDIC, 17-bit [16]

MAGN1 - Signal Magnitude after CORDIC [15:8]
Bit #

Name

Reset

R/W

Description

7:0

MAGN_15_8

0x00

Instantaneous signal magnitude after CORDIC, 17-bit [15:8]

MAGN0 - Signal Magnitude after CORDIC [7:0]
Bit #

Name

Reset

R/W

Description

7:0

MAGN_7_0

0x00

Instantaneous signal magnitude after CORDIC, 17-bit [7:0]

ANG1 - Signal Angular after CORDIC [9:8]
Bit #

Name

Reset

R/W

7:2

ANG1_NOT_USED

0x00

1:0

ANGULAR_9_8

0x00

Description
Instantaneous signal angular after CORDIC, 10-bit [9:8]

ANG0 - Signal Angular after CORDIC [7:0]
Bit #

Name

Reset

R/W

Description

7:0

ANGULAR_7_0

0x00

Instantaneous signal angular after CORDIC, 10-bit [7:0]

SWRU346B

Page 108 of 114

CC120X
CHFILT_I2 - Channel Filter Data Real Part [16]
Bit #

Name

Reset

R/W

7:2

CHFILT_I2_NOT_USED

0x00

CHFILT_STARTUP_VALID

0x01

Description
Channel filter data valid
0
1

CHFILT_I_16

0x00

Channel filter data not valid
Channel filter data valid (asserted after 16 channel filter samples)

Channel filter data, real part, 17-bit [16]

CHFILT_I1 - Channel Filter Data Real Part [15:8]
Bit #

Name

Reset

R/W

Description

7:0

CHFILT_I_15_8

0x00

Channel filter data, real part, 17-bit [15:8]

CHFILT_I0 - Channel Filter Data Real Part [7:0]
Bit #

Name

Reset

R/W

Description

7:0

CHFILT_I_7_0

0x00

Channel filter data, real part, 17-bit [7:0]

CHFILT_Q2 - Channel Filter Data Imaginary Part [16]
Bit #

Name

Reset

R/W

7:1

CHFILT_Q2_NOT_USED

0x00

CHFILT_Q_16

0x00

Description
Channel filter data, imaginary part, 17-bit [16]

CHFILT_Q1 - Channel Filter Data Imaginary Part [15:8]
Bit #

Name

Reset

R/W

Description

7:0

CHFILT_Q_15_8

0x00

Channel filter data, imaginary part, 17-bit [15:8]

CHFILT_Q0 - Channel Filter Data Imaginary Part [7:0]
Bit #

Name

Reset

R/W

Description

7:0

CHFILT_Q_7_0

0x00

Channel filter data, imaginary part, 17-bit [7:0]

GPIO_STATUS - General Purpose Input/Output Status
Bit #

Name

Reset

R/W

Description

7:4

MARC_GDO_STATE

0x00

For test purposes only

3:0

GPIO_STATE

0x00

State of GPIO pins. SERIAL_STATUS.IOC_SYNC_PINS_EN must be 1

FSCAL_CTRL - Frequency Synthesizer Calibration Control
Bit #

Name

Reset

R/W

FSCAL_CTRL_NOT_USED

0x00

Description

6:1

FSCAL_CTRL_RESERVED6_1

0x00

R/W

For test purposes only, use values from SmartRF Studio

LOCK

0x01

Out of lock indicator (FS_CFG.FS_LOCK_EN must be 1). The state of this
signal is only valid in RX, TX, and FSTXON state
0

FS is out of lock

FS out of lock not detected

PHASE_ADJUST - Frequency Synthesizer Phase Adjust
Bit #

Name

Reset

R/W

Description

7:0

PHASE_ADJUST_RESERVED7_0

0x00

For test purposes only, use values from SmartRF Studio

PARTNUMBER - Part Number
Bit #

Name

Reset

R/W

Description

7:0

PARTNUM

0x00

7:0

Chip ID
0x20
CC1200
0x21

CC1201

PARTVERSION - Part Revision
Bit #

Name

Reset

R/W

Description

7:0

PARTVER

0x00

Chip revision

SWRU346B

Page 109 of 114

CC120X
SERIAL_STATUS - Serial Status
Bit #

Name

Reset

R/W

7:6

SERIAL_STATUS_NOT_USED

0x00

SPI_DIRECT_ACCESS_CFG

0x00

R/W

Description
Configures which memory to access when using direct memory access
0

FIFO buffers

FEC workspace or 128 bytes free area

CLK40K

0x00

Internal 40 kHz RC oscillator clock

IOC_SYNC_PINS_EN

0x00

R/W

Enable synchronizer for IO pins. Required for transparent TX and for
reading GPIO_STATUS.GPIO_STATE

CFM_TX_DATA_CLK

0x00

Modulator soft data clock (16 times higher than the programmed
symbol rate)

SERIAL_RX

0x00

Serial RX data

SERIAL_RX_CLK

0x00

Serial RX data clock

MODEM_STATUS1 - Modem Status Reg. 1
Bit #

Name

Reset

R/W

Description

SYNC_FOUND

0x00

RXFIFO_FULL

0x00

Asserted simultaneously as SYNC_EVENT. De-asserted when an SRX
strobe has been issued
Asserted when number of bytes is greater than the RX FIFO threshold. Deasserted when the RX FIFO is empty

RXFIFO_THR

0x00

RXFIFO_EMPTY

0x00

RXFIFO_OVERFLOW

0x00

Asserted when the RX FIFO has overflowed (the radio has received more
bytes after the RXFIFO is full). De-asserted when the RX FIFO is flushed

RXFIFO_UNDERFLOW

0x00

Asserted if the user try to read from an empty RX FIFO. De-asserted when
the RX FIFO is flushed

PQT_REACHED

0x00

Asserted when a preamble is detected (the preamble qualifier value is less
than the programmed PQT threshold). The signal will stay asserted as long
as a preamble is present but will de-assert on sync found (SYNC_EVENT
asserted). If the preamble disappears, the signal will de-assert after a
timeout defined by the sync word length + 10 symbols after preamble was
lost

PQT_VALID

0x01

Asserted after 11, 12, 13, 14,1 5, 17, 24, or 32 bits are received
(depending on the PREAMBLE_CFG0.PQT_VALID_TIMEOUT setting) or
after a preamble is detected

Asserted when number of bytes is greater than the RX FIFO threshold. Deasserted when the RX FIFO is drained below (or is equal) to the same
threshold
High when no bytes reside in the RX FIFO

MODEM_STATUS0 - Modem Status Reg. 0
Bit #

Name

Reset

R/W

MODEM_STATUS0_NOT_USED

0x00

Description

6
5

FEC_RX_OVERFLOW
MODEM_STATUS0_RESERVED5

0x00
0x00

R
R

Internal FEC overflow has occurred
For test purposes only

SYNC_SENT

0x00

Last bit of sync word has been sent

TXFIFO_FULL

0x00

TXFIFO_THR

0x00

TXFIFO_OVERFLOW

0x00

TXFIFO_UNDERFLOW

0x00

Asserted when the TX FIFO is full. De-asserted when the number of bytes
is below threshold
Asserted when number of bytes is greater than or equal to the TX FIFO
threshold. De-asserted when the TX FIFO is drained below the same
threshold
Asserted when the TX FIFO has overflowed (The user have tried to write to
a full TX FIFO). De-asserted when the TX FIFO is flushed
Asserted when the TX FIFO has underflowed (TX FIFO is empty before the
complete packet is sent). De-asserted when the TX FIFO is flushed

SWRU346B

Page 110 of 114

CC120X
MARC_STATUS1 - MARC Status Reg. 1
Bit #

Name

Reset

R/W

Description

7:0

MARC_STATUS_OUT

0x00

This register should be read to find what caused the MCU_WAKEUP signal
to be asserted
00000000

No failure

00000001

RX timeout occurred

00000010

RX termination based on CS or PQT

00000011

eWOR sync lost (16 slots with no successful reception)

00000100
00000101

Packet discarded due to maximum length filtering
Packet discarded due to address filtering

00000110

Packet discarded due to CRC filtering

00000111

TX FIFO overflow error occurred

00001000

TX FIFO underflow error occurred

00001001

RX FIFO overflow error occurred

00001010

RX FIFO underflow error occurred

00001011

TX ON CCA failed

01000000

TX finished successfully

10000000

RX finished successfully (a packet is in the RX FIFO ready
to be read)

MARC_STATUS0 - MARC Status Reg. 0
Bit #

Name

Reset

R/W

7:4

MARC_STATUS0_NOT_USED

0x00

Description

MARC_STATUS0_RESERVED3

0x00

For test purposes only

TXONCCA_FAILED

0x00

This bit can be read after the TXONCCA_DONE signal has been asserted
0

The channel was clear. The radio will enter TX state

The channel was busy. The radio will remain in RX state

MARC_STATUS0_RESERVED1

0x00

For test purposes only

RCC_CAL_VALID

0x00

RCOSC has been calibrated at least once

PA_IFAMP_TEST - Power Amplifier Intermediate Frequency Amplifier Test
Bit #

Name

Reset

R/W

7:5

PA_IFAMP_TEST_NOT_USED

0x00

4:0

PA_IFAMP_TEST_RESERVED4_0

0x00

R/W

Description
For test purposes only, use values from SmartRF Studio

FSRF_TEST - Frequency Synthesizer Test
Bit #

Name

Reset

R/W

FSRF_TEST_NOT_USED

0x00

6:0

FSRF_TEST_RESERVED6_0

0x00

R/W

Description
For test purposes only, use values from SmartRF Studio

PRE_TEST - Frequency Synthesizer Prescaler Test
Bit #

Name

Reset

R/W

7:5

PRE_TEST_NOT_USED

0x00

4:0

PRE_TEST_RESERVED4_0

0x00

R/W

Description
For test purposes only, use values from SmartRF Studio

PRE_OVR - Frequency Synthesizer Prescaler Override
Bit #

Name

Reset

R/W

Description

7:0

PRE_OVR_RESERVED7_0

0x00

R/W

For test purposes only, use values from SmartRF Studio

ADC_TEST - Analog to Digital Converter Test
Bit #

Name

Reset

R/W

7:6

ADC_TEST_NOT_USED

0x00

Description

5:0

ADC_TEST_RESERVED5_0

0x00

R/W

For test purposes only, use values from SmartRF Studio

Description

DVC_TEST - Digital Divider Chain Test
Bit #

Name

Reset

R/W

7:5

DVC_TEST_NOT_USED

0x00

4:0

DVC_TEST_RESERVED4_0

0x0B

R/W

For test purposes only, use values from SmartRF Studio

Description

ATEST - Analog Test
Bit #

Name

Reset

R/W

ATEST_NOT_USED

0x00

6:0

ATEST_RESERVED6_0

0x40

R/W

For test purposes only, use values from SmartRF Studio

Description

ATEST_LVDS - Analog Test LVDS
Bit #

Name

Reset

R/W

7:6

ATEST_LVDS_NOT_USED

0x00

5:0

ATEST_LVDS_RESERVED5_0

0x00

R/W

For test purposes only, use values from SmartRF Studio

SWRU346B

Page 111 of 114

CC120X
ATEST_MODE - Analog Test Mode
Bit #

Name

Reset

R/W

Description

7:0

ATEST_MODE_RESERVED7_0

0x00

R/W

For test purposes only, use values from SmartRF Studio

XOSC_TEST1 - Crystal Oscillator Test Reg. 1
Bit #

Name

Reset

R/W

Description

7:0

XOSC_TEST1_RESERVED7_0

0x3C

R/W

For test purposes only, use values from SmartRF Studio

XOSC_TEST0 - Crystal Oscillator Test Reg. 0
Bit #

Name

Reset

R/W

Description

7:0

XOSC_TEST0_RESERVED7_0

0x00

R/W

For test purposes only, use values from SmartRF Studio

AES - Advanced Encryption Standard Status
Bit #

Name

Reset

R/W

7:2

AES_NOT_USED

0x00

AES_ABORT

0x00

R/W

AES_RUN

0x00

R/W

Description
Setting this bit to 1 will abort the AES encryption cycle.
The bit will be cleared by HW when the abortion sequence is completed
AES enable. The bit will be cleared by HW when an encryption cycle has
finished
0 Halt the current AES encryption
1

AES module is enabled and the AES encryption cycle will
start/continue given that AES_ABORT is low

MDM_TEST - Modem Test
Bit #

Name

Reset

R/W

7:4

MDM_TEST_NOT_USED

0x00

Description

3:0

MDM_TEST_RESERVED3_0

0x00

R/W

For test purposes only, use values from SmartRF Studio

RXFIRST - RX FIFO Pointer First Entry
Bit #

Name

Reset

R/W

Description

7:0

RX_FIRST

0x00

Pointer to the first entry in the RX FIFO

TXFIRST - TX FIFO Pointer First Entry
Bit #

Name

Reset

R/W

Description

7:0

TX_FIRST

0x00

Pointer to the first entry in the TX FIFO

RXLAST - RX FIFO Pointer Last Entry
Bit #

Name

Reset

R/W

Description

7:0

RX_LAST

0x00

Pointer to the last entry in the RX FIFO

TXLAST - TX FIFO Pointer Last Entry
Bit #

Name

Reset

R/W

Description

7:0

TX_LAST

0x00

Pointer to the last entry in the TX FIFO

NUM_TXBYTES - TX FIFO Status
Bit #

Name

Reset

R/W

Description

7:0

TXBYTES

0x00

Number of bytes in the TX FIFO

NUM_RXBYTES - RX FIFO Status
Bit #

Name

Reset

R/W

Description

7:0

RXBYTES

0x00

Number of bytes in the RX FIFO

Description

FIFO_NUM_TXBYTES - TX FIFO Status
Bit #

Name

Reset

R/W

7:4

FIFO_NUM_TXBYTES_NOT_USED

0x00

3:0

FIFO_TXBYTES

0x0F

Number of free entries in the TX FIF0. 1111b means that there are 15 or
more free entries

Description

FIFO_NUM_RXBYTES - RX FIFO Status
Bit #

Name

Reset

R/W

7:4

FIFO_NUM_RXBYTES_NOT_USED

0x00

3:0

FIFO_RXBYTES

0x00

Number of available bytes in the RX FIFO. 1111b means that there are
15 or more bytes available to read

RXFIFO_PRE_BUF - RX FIFO First Byte
Bit #

Name

Reset

R/W

Description

7:0

PRE_BUF

0x00

Contains the first byte received in the RX FIFO when the RX FIFO is
empty (i.e. RXFIRST = RXLAST)

SWRU346B

Page 112 of 114

CC120X
AES_KEY15 - Advanced Encryption Standard Key [127:120]
Bit #

Name

Reset

R/W

Description

7:0

AES_KEY_127_120

0x00

R/W

16 bytes AES key, [127:120]

AES_KEY14 - Advanced Encryption Standard Key [119:112]
Bit #

Name

Reset

R/W

Description

7:0

AES_KEY_119_112

0x00

R/W

16 bytes AES key, [119:112]

AES_KEY13 - Advanced Encryption Standard Key [111:104]
Bit #

Name

Reset

R/W

Description

7:0

AES_KEY_111_104

0x00

R/W

16 bytes AES key, [111:104]

.
.
AES_KEY0 - Advanced Encryption Standard Key [7:0]
Bit #

Name

Reset

R/W

Description

7:0

AES_KEY_7_0

0x00

R/W

16 bytes AES key, [7:0]

AES_BUFFER15 - Advanced Encryption Standard Buffer [127:120]
Bit #

Name

Reset

R/W

Description

7:0

AES_BUFFER_127_120

0x00

R/W

AES data buffer [127:120]. The content serves as input to the AES encryption
module, and the content will be overwritten with the encrypted data when the AES
encryption is completed

AES_BUFFER14 - Advanced Encryption Standard Buffer [119:112]
Bit #

Name

Reset

R/W

Description

7:0

AES_BUFFER_119_112

0x00

R/W

AES data buffer [119:112]. See AES_BUFFER15 for details

AES_BUFFER13 - Advanced Encryption Standard Buffer [111:104]
Bit #

Name

Reset

R/W

Description

7:0

AES_BUFFER_111_104

0x00

R/W

AES data buffer [111:104]. See AES_BUFFER15for details

.
.
AES_BUFFER0 - Advanced Encryption Standard Buffer [7:0]
Bit #

Name

Reset

R/W

Description

7:0

AES_BUFFER_7_0

0x00

R/W

AES data buffer [7:0]. See AES_BUFFER15 for details

SWRU346B

Page 113 of 114

CC120X
13 Soldering Information
The recommendations for lead-free reflow in IPC/JEDEC J-STD-020 should be followed.

14 Development Kit Ordering Information
Orderable Evaluation Module
CC1200DK
CC1200EMK-868-930
CC1200EMK-420-470

Description
CC1200 Development Kit, 868-930 MHz
CC1200 Evaluation Module Kit, 868-930 MHz (add-on kit for CC1200DK)
CC1200 Evaluation Module Kit, 420-470 MHz (add-on kit for CC1200DK)

Table 40: Development Kit Ordering Information

15 References
[1] SmartRF Studio (SWRC176.zip)
[2] EN 300 220 V2.3.1: “Electromagnetic compatibility and Radio spectrum Matters (ERM); Short
Range Devices (SRD); Radio equipment to be used in the 25 MHz to 1000 MHz frequency
range with power levels rang up to 500 mW” (www.etsi.org)
[3] IEEE Std 802.15.4g-2012 (Amendment to IEEE Std 802.15.4-2011)
[4] DN403 CC112X/CC120X On-Chip Temperature Sensor (SWRA415.pdf)

16 General Information
16.1 Document History
Revision
Rev. 1.0
SWRU346
SWRU346A

Date
28.09.2011
30.04.2013
01.07.2013

SWRU346B

27.09.2013

Description/Changes
Advance Information
First Release
Added info to Section 3.4 saying that interrupts on GPIO signals must be disabled when
changing the GPIO configuration.
In Section 9.6.1, info added on how to use Event 2 for RC oscillator calibration.
Changed description of FS_DIG0.
Added info to Section 6.1 regarding the relationship between RX Filter BW and symbol rate
for different settings of SYNC_CFG0.RX_CONFIG_LIMITATION = 0
Added info regarding recommended AGC settings in the
SYNC_CFG0.RX_CONFIG_LIMITATION register field
Removed all references to MDMCFG0.CHFILT_BYPASS as this feature does not work
Added info in register field RFEND_CFG0.ANT_DIV_RX_TERM_CFG saying that
MDMCFG1.CARRIER_SENSE_GATE must be 0 when PQT termination is enabled.
AGC_CARRIER_SENSE changed name to CARRIER_SENSE
Added information about no RSSI available for Mode Switch packets in 802.15.4g mode
(Section 8.7.2.2 on page 57)
Changed PREAMBLE_CFG0.PQT_VALID_TIMEOUT
Section 6.8: Added equations for PQT response time

Table 41: Document History

SWRU346B

Page 114 of 114

IMPORTANT NOTICE
Texas Instruments Incorporated and its subsidiaries (TI) reserve the right to make corrections, enhancements, improvements and other
changes to its semiconductor products and services per JESD46, latest issue, and to discontinue any product or service per JESD48, latest
issue. Buyers should obtain the latest relevant information before placing orders and should verify that such information is current and
complete. All semiconductor products (also referred to herein as “components”) are sold subject to TI’s terms and conditions of sale
supplied at the time of order acknowledgment.
TI warrants performance of its components to the specifications applicable at the time of sale, in accordance with the warranty in TI’s terms
and conditions of sale of semiconductor products. Testing and other quality control techniques are used to the extent TI deems necessary
to support this warranty. Except where mandated by applicable law, testing of all parameters of each component is not necessarily
performed.
TI assumes no liability for applications assistance or the design of Buyers’ products. Buyers are responsible for their products and
applications using TI components. To minimize the risks associated with Buyers’ products and applications, Buyers should provide
adequate design and operating safeguards.
TI does not warrant or represent that any license, either express or implied, is granted under any patent right, copyright, mask work right, or
other intellectual property right relating to any combination, machine, or process in which TI components or services are used. Information
published by TI regarding third-party products or services does not constitute a license to use such products or services or a warranty or
endorsement thereof. Use of such information may require a license from a third party under the patents or other intellectual property of the
third party, or a license from TI under the patents or other intellectual property of TI.
Reproduction of significant portions of TI information in TI data books or data sheets is permissible only if reproduction is without alteration
and is accompanied by all associated warranties, conditions, limitations, and notices. TI is not responsible or liable for such altered
documentation. Information of third parties may be subject to additional restrictions.
Resale of TI components or services with statements different from or beyond the parameters stated by TI for that component or service
voids all express and any implied warranties for the associated TI component or service and is an unfair and deceptive business practice.
TI is not responsible or liable for any such statements.
Buyer acknowledges and agrees that it is solely responsible for compliance with all legal, regulatory and safety-related requirements
concerning its products, and any use of TI components in its applications, notwithstanding any applications-related information or support
that may be provided by TI. Buyer represents and agrees that it has all the necessary expertise to create and implement safeguards which
anticipate dangerous consequences of failures, monitor failures and their consequences, lessen the likelihood of failures that might cause
harm and take appropriate remedial actions. Buyer will fully indemnify TI and its representatives against any damages arising out of the use
of any TI components in safety-critical applications.
In some cases, TI components may be promoted specifically to facilitate safety-related applications. With such components, TI’s goal is to
help enable customers to design and create their own end-product solutions that meet applicable functional safety standards and
requirements. Nonetheless, such components are subject to these terms.
No TI components are authorized for use in FDA Class III (or similar life-critical medical equipment) unless authorized officers of the parties
have executed a special agreement specifically governing such use.
Only those TI components which TI has specifically designated as military grade or “enhanced plastic” are designed and intended for use in
military/aerospace applications or environments. Buyer acknowledges and agrees that any military or aerospace use of TI components
which have not been so designated is solely at the Buyer's risk, and that Buyer is solely responsible for compliance with all legal and
regulatory requirements in connection with such use.
TI has specifically designated certain components as meeting ISO/TS16949 requirements, mainly for automotive use. In any case of use of
non-designated products, TI will not be responsible for any failure to meet ISO/TS16949.
Products

Applications

Audio

www.ti.com/audio

Automotive and Transportation

www.ti.com/automotive

Amplifiers

amplifier.ti.com

Communications and Telecom

www.ti.com/communications

Data Converters

dataconverter.ti.com

Computers and Peripherals

www.ti.com/computers

DLP® Products

www.dlp.com

Consumer Electronics

www.ti.com/consumer-apps

DSP

dsp.ti.com

Energy and Lighting

www.ti.com/energy

Clocks and Timers

www.ti.com/clocks

Industrial

www.ti.com/industrial

Interface

interface.ti.com

Medical

www.ti.com/medical

Logic

logic.ti.com

Security

www.ti.com/security

Power Mgmt

power.ti.com

Space, Avionics and Defense

www.ti.com/space-avionics-defense

Microcontrollers

microcontroller.ti.com

Video and Imaging

www.ti.com/video

RFID

www.ti-rfid.com

OMAP Applications Processors

www.ti.com/omap

TI E2E Community

e2e.ti.com

Wireless Connectivity

Source Exif Data:

File Type                       : PDF
File Type Extension             : pdf
MIME Type                       : application/pdf
PDF Version                     : 1.4
Linearized                      : No
Page Mode                       : UseOutlines
Page Count                      : 115
Modify Date                     : 2013:09:26 08:45:56-05:00
Producer                        : iText 2.1.7 by 1T3XT
Keywords                        : SWRU346B, SWRU346
Title                           : CC120X Low-Power High Performance  Sub-1 GHz RF Transceivers (Rev. B)
Author                          : Texas Instruments, Incorporated [SWRU346,B.]
Create Date                     : 2013:09:26 08:45:56-05:00
Creator                         : Microsoft® Word 2010
Subject                         : User's Guide

EXIF Metadata provided by EXIF.tools

CC120X Low Power High Performance Sub 1 GHz RF Transceivers (Rev. B) Cc1201 User Guide

cc1200-user-guide

cc120x-user-guide

User's%20Guide%20-%20swru346b

Navigation menu

Versions of this User Manual:

Views

Navigation