CC2430 Datasheet, PDF (187/212 Pages) Texas Instruments – A True System-on-Chip solution for 2.4 GHz IEEE 802.15.4 / ZigBee-TM

CC2430
MDMCTRL0L (0xDF03)
Bit Name
7:6 CCA_MODE[1:0]
5
AUTOCRC
4
AUTOACK
3:0 PREAMBLE_LENGTH[3:0]
Radio : Radio Registers
Reset
11
1
0
0010
R/W
R/W
R/W
R/W
R/W
Description
Clear Channel Assessment mode select.
00 : Reserved
01 : CCA=1 when RSSI < CCA_THR-CCA_HYST
CCA=0 when RSSI >= CCA_THR
10 : CCA=1 when not receiving a packet
11 : CCA=1 when RSSI < CCA_THR-CCA_HYST and not
receiving a packet
CCA=0 when RSSI >= CCA_THR or receiving a packet
In packet mode a CRC-16 (ITU-T) is calculated and is
transmitted after the last data byte in TX. In RX CRC is
calculated and checked for validity.
If AUTOACK is enabled, all packets accepted by address
recognition with the acknowledge request flag set and a
valid CRC are acknowledged 12 symbol periods after being
received if MDMCTRL1H.SLOTTED_ACK = 0.
Acknowledgment is at the beginning of the first backoff slot
more than 12 symbol periods after the end of the received
frame if the MDMCTRL1H.SLOTTED_ACK = 1
0 : AUTOACK disabled
1 : AUTOACK enabled
The number of preamble bytes (2 zero-symbols) to be sent
in TX mode prior to the SYNCWORD. The reset value of
0010 is compliant with IEEE 802.15.4, since the 4^th zero
byte is included in the SYNCWORD.
0000 : 1 leading zero bytes (not recommended)
0001 : 2 leading zero bytes (not recommended)
0010 : 3 leading zero bytes (IEEE 802.15.4 compliant)
0011 : 4 leading zero bytes
…
1111 : 16 leading zero bytes
MDMCTRL1H (0xDF04)
Bit Name
7
SLOTTED_ACK
6
-
5
CORR_THR_SFD
4:0 CORR_THR[4:0]
Reset
0
0
1
0x10
R/W
R/W
R/W
R/W
R/W
Description
SLOTTED_ACK defines the timing of automatically
transmitted acknowledgment frames.
0 : The acknowledgment frame is transmitted 12 symbol
periods after the incoming frame.
1 : The acknowledgment frame is transmitted between 12
and 30 symbol periods after the incoming frame. The timing
is defined such that there is an integer number of 20-symbol
periods between the received and the transmitted SFDs.
This may be used to transmit slotted acknowledgment
frames in a beacon enabled network.
Reserved
CORR_THR_SFD defines the level at which the
CORR_THR correlation threshold is used to filter out
received frames.
0 : Same filtering as CC2420, should be combined with a
CORR_THR of 0x14
1 : More extensive filtering is performed, which will result in
less false frame detections e.g. caused by noise.
Demodulator correlator threshold value, required before
SFD search.
CC2430 Data Sheet (rev. 2.1) SWRS036F
Page 187 of 211