CC2420 Chipcon AS, CC2420 Datasheet - Page 62

• Manufacturer Part Number: CC2420
• Description: 2.4 GHz RF Transceiver for IEEE 802.15.4 and ZigBee
• Manufacturer: Chipcon AS

MDMCTRL0 (0x11) - Modem Control Register 0
15:14
13
12
11
10:8
7:6
5
4
3:0
Chipcon AS SmartRF ® CC2420 Preliminary Datasheet (rev 1.0), 2003-11-17
Bit
Field Name
-
RESERVED_FRAME_MODE
PAN_COORDINATOR
ADR_DECODE
CCA_HYST[2:0]
CCA_MODE[1:0]
AUTOCRC
AUTOACK
PREAMBLE_LENGTH
[3:0]
Reset
0
0
0
1
2
3
1
0
2
R/W
W0
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
SmartRF
Description
Reserved, write as 0
Mode for accepting reserved IEE 802.15.4 frame types when
address recognition is enabled (
0 : Reserved frame types (100, 101, 110, 111) are rejected by
address recognition.
1 : Reserved frame types (100, 101, 110, 111) are always
accepted by address recognition. No further address decoding is
done.
When address recognition is disabled (
0
care.
Should be set high when the device is a PAN Coordinator. Used
for filtering packets with no desitination address, as speccified in
section 7.5.6.2 in 802.15.4, D18
Hardware Address decode enable.
0 : Address decoding is disabled
1 : Address decoding is enabled
CCA Hysteresis in dB, values 0 through 7 dB
0 : Reserved
1 : CCA=1 when RSSI_VAL < CCA_THR - CCA_HYST
2 : CCA=1 when not receiving valid IEEE 802.15.4 data,
3 : CCA=1 when RSSI_VAL < CCA_THR - CCA_HYST andnot
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 set, all packets accepted by address recognition
with the acknowledge request flag set and a valid CRC are
ack’ed 12 symbol periods after being received.
The number of preamble bytes (2 zero-symbols) to be sent in TX
mode prior to the SYNCWORD, encoded in steps of 2. The reset
value of 2 is compliant with IEEE 802.15.4, since the 4
byte is included in the SYNCWORD.
0 : 1 leading zero bytes (not recommended)
1 : 2 leading zero bytes (not recommended)
2 : 3 leading zero bytes (IEEE 802.15.4 compliant)
3 : 4 leading zero bytes
…
15 : 16 leading zero bytes
), all frames are received and
CCA=0 when RSSI_VAL ≥ CCA_THR
CCA=0 otherwise
CCA=0 when RSSI_VAL ≥ CCA_THR or receiving a packet
receiving valid IEEE 802.15.4 data.
®
CC2420
RESERVED_FRAME_MODE
MDMCTRL0.ADR_DECODE = 1
MDMCTRL0.ADR_DECODE =
Page 62 of 85
th
is don’t
zero
).