Datasheet

MCP2515
DS20001801J-page 22  2003-2019 Microchip Technology Inc.
REGISTER 3-7: TXBnDLC: TRANSMIT BUFFER n DATA LENGTH CODE REGISTER
(ADDRESS: 35h, 45h, 55h)
U-0 R/W-x U-0 U-0 R/W-x R/W-x R/W-x R/W-x
—RTR— — DLC3
(1)
DLC2
(1)
DLC1
(1)
DLC0
(1)
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 Unimplemented: Read as ‘0’
bit 6 RTR: Remote Transmission Request bit
1 = Transmitted message will be a remote transmit request
0 = Transmitted message will be a data frame
bit 5-4 Unimplemented: Reads as ‘0’
bit 3-0 DLC[3:0]: Data Length Code bits
(1)
Sets the number of data bytes to be transmitted (0 to 8 bytes).
Note 1: It is possible to set the DLC[3:0] bits to a value greater than eight; however, only eight bytes are
transmitted.
REGISTER 3-8: TXBnDm: TRANSMIT BUFFER n DATA BYTE m REGISTER
(ADDRESS: 36h-3Dh, 46h-4Dh, 56h-5Dh)
R/W-x R/W-x R/W-x R/W-x R/W-x R/W-x R/W-x R/W-x
TXBnDm7 TXBnDm6 TXBnDm5 TXBnDm4 TXBnDm3 TXBnDm2 TXBnDm1 TXBnDm0
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 7-0 TXBnDm[7:0]: Transmit Buffer n Data Field Byte m bits