MRF24J40_08 Datasheet, PDF (28/152 Pages) Microchip Technology – IEEE 802.15.4™ 2.4 GHz RF Transceiver

MRF24J40
REGISTER 2-16: TXMCR: CSMA-CA MODE CONTROL REGISTER (ADDRESS: 0x11)
R/W-0
NOCSMA
bit 7
R/W-0
BATLIFEXT
R/W-0
SLOTTED
R/W-1
R/W-1
MACMINBE1 MACMINBE0
R/W-1
CSMABF2
R/W-0
CSMABF1
R/W-0
CSMABF0
bit 0
Legend:
R = Readable bit
-n = Value at POR
W = Writable bit
‘1’ = Bit is set
U = Unimplemented bit, read as ‘0’
‘0’ = Bit is cleared
x = Bit is unknown
bit 7
bit 6
bit 5
bit 4-3
bit 2-0
NOCSMA: No Carrier Sense Multiple Access (CSMA) Algorithm bits
1 = Disable CSMA-CA algorithm when transmitting in Unslotted mode with GTSSWITCH
(TXPEND 0x21<1>) bit set
0 = Enable CSMA-CA algorithm when transmitting in Unslotted mode with GTSSWITCH
(TXPEND 0x21<1>) bit set (default)
BATLIFEXT: Battery Life Extension Mode bit (macBattLifeExt)
1 = Enable
0 = Disable (default)
SLOTTED: Slotted CSMA-CA Mode bit
1 = Enable Slotted CSMA-CA mode
0 = Disable Slotted CSMA-CA mode (default)
MACMINBE<1:0>: MAC Minimum Backoff Exponent bits (macMinBE)
The minimum value of the backoff exponent in the CSMA-CA algorithm. Note that if this value is set to
‘0’, collision avoidance is disabled.⁽¹⁾
Default: 0x3.
CSMABF<2:0>: CSMA Backoff bits (macMaxCSMABackoff)
The maximum number of backoffs the CSMA-CA algorithm will attempt before declaring a channel
access failure.⁽¹⁾
111 = Undefined
110 = Undefined
101 = 5
100 = 4 (default)
011 = 3
010 = 2
001 = 1
000 = 0
Note 1: Refer to IEEE 802.15.4™-2003 Standard, Table 71 – MAC PIB attributes.
DS39776B-page 26
Preliminary
© 2008 Microchip Technology Inc.