Specifications
CC1101 
      SWRS061I     Page 73 of 98
0x04: SYNC1 – Sync Word, High Byte 
Bit 
Field Name 
Reset 
R/W 
Description 
7:0 
SYNC[15:8] 
211 (0xD3) 
R/W 
8 MSB of 16-bit sync word 
0x05: SYNC0 – Sync Word, Low Byte 
Bit 
Field Name 
Reset 
R/W 
Description 
7:0 
SYNC[7:0] 
145 (0x91) 
R/W 
8 LSB of 16-bit sync word 
0x06: PKTLEN – Packet Length  
Bit 
Field Name 
Reset 
R/W 
Description 
7:0 
PACKET_LENGTH 
255 (0xFF) 
R/W 
Indicates the packet length when fixed packet length mode is enabled. If 
variable packet length mode is used, this value indicates the maximum 
packet length allowed. This value must be different from 0. 
0x07: PKTCTRL1 – Packet Automation Control 
Bit 
Field Name 
Reset 
R/W 
Description 
7:5 
PQT[2:0] 
0 (0x00) 
R/W 
Preamble quality estimator threshold. The preamble quality estimator 
increases an internal counter by one each time a bit is received that is 
different from the previous bit, and decreases the counter by 8 each time a 
bit is received that is the same as the last bit. 
A threshold of 4∙PQT for this counter is used to gate sync word detection. 
When PQT=0 a sync word is always accepted. 
4 
0 
R0 
Not Used. 
3 
CRC_AUTOFLUSH 
0 
R/W 
Enable automatic flush of RX FIFO when CRC is not OK. This requires that 
only one packet is in the RXIFIFO and that packet length is limited to the 
RX FIFO size. 
2 
APPEND_STATUS 
1 
R/W 
When enabled, two status bytes will be appended to the payload of the 
packet. The status bytes contain RSSI and LQI values, as well as CRC OK. 
1:0 
ADR_CHK[1:0] 
0 (00) 
R/W 
Controls address check configuration of received packages. 
Setting 
Address check configuration 
0 (00) 
No address check 
1 (01) 
Address check, no broadcast 
2 (10) 
Address check and 0 (0x00) broadcast 
3 (11) 
Address check and 0 (0x00) and 255 (0xFF) 
broadcast 










