Data Sheet

© 2005 Microchip Technology Inc. Preliminary DS21801D-page 21
MCP2515
REGISTER 3-7: TXBnDLC - TRANSMIT BUFFER n DATA LENGTH CODE
(ADDRESS: 35h, 45h, 55h)
REGISTER 3-8: TXBnDm – TRANSMIT BUFFER n DATA BYTE m
(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
—RTR— — DLC3DLC2DLC1DLC0
bit 7 bit 0
bit 7 Unimplemented: Reads 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: Data Length Code <3:0> bits
Sets the number of data bytes to be transmitted (0 to 8 bytes)
Note: It is possible to set the DLC to a value greater than 8, however only 8 bytes are
transmitted
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
R/W-x R/W-x R/W-x R/W-x R/W-x R/W-x R/W-x R/W-x
TXBnDm
7
TXBnDm
6
TXBnDm
5
TXBnDm
4
TXBnDm
3
TXBnDm
2
TXBnDm
1
TXBnDm
0
bit 7 bit 0
bit 7-0 TXBnD
M7:TXBnDM0: Transmit Buffer n Data Field Bytes m
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