Datasheet

MCP2515
DS21801E-page 42 © 2007 Microchip Technology Inc.
REGISTER 5-1: CNF1 – CONFIGURATION 1 (ADDRESS: 2Ah)
R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0
SJW1 SJW0 BRP5 BRP4 BRP3 BRP2 BRP1 BRP0
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7-6 SJW: Synchronization Jump Width Length bits <1:0>
11 = Length = 4 x T
Q
10 = Length = 3 x TQ
01 = Length = 2 x TQ
00 = Length = 1 x TQ
bit 5-0 BRP: Baud Rate Prescaler bits <5:0>
TQ = 2 x (BRP + 1)/FOSC
REGISTER 5-2: CNF2 – CONFIGURATION 1 (ADDRESS: 29h)
R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0
BTLMODE SAM PHSEG12 PHSEG11 PHSEG10 PRSEG2 PRSEG1 PRSEG0
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7 BTLMODE: PS2 Bit Time Length bit
1 = Length of PS2 determined by PHSEG22:PHSEG20 bits of CNF3
0 = Length of PS2 is the greater of PS1 and IPT (2 T
Q)
bit 6 SAM: Sample Point Configuration bit
1 = Bus line is sampled three times at the sample point
0 = Bus line is sampled once at the sample point
bit 5-3 PHSEG1: PS1 Length bits<2:0>
(PHSEG1 + 1) x TQ
bit 2-0 PRSEG: Propagation Segment Length bits <2:0>
(PRSEG + 1) x T
Q