CC2420
MDMCTRL0 (0x11) - Modem Control Register 0
| Bit | Field Name | Reset | R/W |
| 15:14 | - | 0 | W0 |
| 13 | RESERVED_FRAME_MODE | 0 | R/W |
12 | PAN_COORDINATOR | 0 | R/W |
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11 | ADR_DECODE | 1 | R/W |
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10:8 | CCA_HYST[2:0] | 2 | R/W |
7:6 | CCA_MODE[1:0] | 3 | R/W |
5 | AUTOCRC | 1 | R/W |
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4 | AUTOACK | 0 | R/W |
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3:0 | PREAMBLE_LENGTH | 2 | R/W |
| [3:0] |
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Description
Reserved, write as 0
Mode for accepting reserved IEE 802.15.4 frame types when address recognition is enabled (MDMCTRL0.ADR_DECODE = 1).
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 (MDMCTRL0.ADR_DECODE = 0), all frames are received and RESERVED_FRAME_MODE is don’t care.
Should be set high when the device is a PAN Coordinator. Used for filtering packets with no destination address, as specified 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 CCA=0 when RSSI_VAL ≥ CCA_THR
2: CCA=1 when not receiving valid IEEE 802.15.4 data, CCA=0 otherwise
3: CCA=1 when RSSI_VAL < CCA_THR - CCA_HYST and not
receiving valid IEEE 802.15.4 data.
CCA=0 when RSSI_VAL ≥ CCA_THR or receiving a packet
In packet mode a
If AUTOACK is set, all packets accepted by address recognition with the acknowledge request flag set and a valid CRC are acknowledged 12 symbol periods after being received.
The number of preamble bytes (2
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
SWRS041B | Page 64 of 89 |
