MRF24J40_08 Datasheet, PDF (58/152 Pages) Microchip Technology – IEEE 802.15.4™ 2.4 GHz RF Transceiver

MRF24J40
REGISTER 2-54: BBREG2: BASEBAND 2 REGISTER (ADDRESS: 0x3A)
R/W-0
R/W-1
CCAMODE1 CCAMODE0
bit 7
R/W-0
CCACSTH3
R/W-0
CCACSTH2
R/W-1
CCATCSH1
R/W-0
CCACSTH0
R/W-0
r
R/W-0
r
bit 0
Legend:
R = Readable bit
-n = Value at POR
r = reserved
W = Writable bit
‘1’ = Bit is set
U = Unimplemented bit, read as ‘0’
‘0’ = Bit is cleared
x = Bit is unknown
bit 7-6
bit 5-2
bit 1-0
CCAMODE<1:0>: Clear Channel Assessment (CCA) Mode bits
11 = CCA Mode 3: Carrier sense with energy above threshold. CCA shall report a busy medium only
upon the detection of a signal with the modulation and spreading characteristics of IEEE 802.15.4™
with energy above the Energy Detection (ED) threshold.
10 = CCA Mode 1: Energy above threshold. CCA shall report a busy medium upon detecting any
energy above the Energy Detection (ED) threshold.
01 = CCA Mode 2: Carrier sense only. CCA shall report a busy medium only upon the detection of a
signal with the modulation and spreading characteristics of IEEE 802.15.4. This signal may be
above or below the Energy Detection (ED) threshold (default).
00 = Reserved
CCACSTH<3:0>: Clear Channel Assessment (CCA) Carrier Sense (CS) Threshold bits
1111 =
1110 = Recommended value
1101 =
...
0010 = (default)
0001 =
0000 =
Reserved: Maintain as ‘0’
REGISTER 2-55: BBREG3: BASEBAND 3 REGISTER (ADDRESS: 0x3B)
R/W-1
R/W-1
R/W-0
R/W-1
R/W-1
PREVALIDTH3 PREVALIDTH2 PREVALIDTH1 PREVALIDTH0 PREDETTH2
bit 7
R/W-0
PREDETTH1
R/W-0
PREDETTH0
R/W-0
r
bit 0
Legend:
R = Readable bit
-n = Value at POR
r = reserved
W = Writable bit
‘1’ = Bit is set
U = Unimplemented bit, read as ‘0’
‘0’ = Bit is cleared
x = Bit is unknown
bit 7-4
bit 3-1
bit 0
PREVALIDTH<3:0>: Preamble Search Energy Valid Threshold bits
1101 = IEEE 802.15.4™ (250 kbps) optimized value (default)
0011 = Turbo mode (625 kbps) optimized value
PREDETTH<2:0>: Preamble Search Energy Detection Threshold bits
Default value: 0x4.
Reserved: Maintain as ‘0’
DS39776B-page 56
Preliminary
© 2008 Microchip Technology Inc.