Data Sheet
Table Of Contents
- 1.0 Device Overview
- 2.0 Can Message Frames
- 3.0 Message Transmission
- 4.0 Message Reception
- 5.0 Bit Timing
- 6.0 Error Detection
- 7.0 Interrupts
- 8.0 Oscillator
- 9.0 RESET
- 10.0 Modes of Operation
- 11.0 Register Map
- 12.0 SPI™ Interface
- 12.1 Overview
- 12.2 Reset Instruction
- 12.3 Read Instruction
- 12.4 Read RX Buffer Instruction
- 12.5 Write Instruction
- 12.6 Load TX Buffer Instruction
- 12.7 Request-To-Send (RTS) Instruction
- 12.8 Read Status Instruction
- 12.9 RX Status Instruction
- 12.10 Bit Modify Instruction
- Figure 12-1: Bit Modify
- Table 12-1: SPI™ Instruction Set
- Figure 12-2: Read instruction
- Figure 12-3: Read RX Buffer Instruction
- Figure 12-4: Byte Write instruction
- Figure 12-5: Load TX Buffer
- Figure 12-6: Request-to-send (RTS) instruction
- Figure 12-7: BIT Modify instruction
- Figure 12-8: Read Status instruction
- Figure 12-9: RX StatUs Instruction
- Figure 12-10: SPI™ Input Timing
- Figure 12-11: SPI™ Output TIming
- 13.0 Electrical Characteristics
- 14.0 PackAging Information

© 2005 Microchip Technology Inc. Preliminary DS21801D-page 19
MCP2515
REGISTER 3-2: TXRTSCTRL – TXnRTS PIN CONTROL AND STATUS REGISTER
(ADDRESS: 0Dh)
REGISTER 3-3: TXBnSIDH – TRANSMIT BUFFER n STANDARD IDENTIFIER HIGH
(ADDRESS: 31h, 41h, 51h)
U-0 U-0 R-x R-x R-x R/W-0 R/W-0 R/W-0
— — B2RTS B1RTS B0RTS B2RTSM B1RTSM B0RTSM
bit 7 bit 0
bit 7 Unimplemented: Read as ‘0’
bit 6 Unimplemented: Read as ‘0’
bit 5 B2RTS: TX2RTS
Pin State bit
- Reads state of TX2RTS pin when in Digital Input mode
- Reads as ‘0’ when pin is in ‘Request-to-Send’ mode
bit 4 B1RTS: TX1RTX
Pin State bit
- Reads state of TX1RTS pin when in Digital Input mode
- Reads as ‘0’ when pin is in ‘Request-to-Send’ mode
bit 3 B0RTS: TX0RTS
Pin State bit
- Reads state of TX0RTS
pin when in Digital Input mode
- Reads as ‘0’ when pin is in ‘Request-to-Send’ mode
bit 2 B2RTSM: TX2RTS
Pin mode bit
1 = Pin is used to request message transmission of TXB2 buffer (on falling edge)
0 = Digital input
bit 1 B1RTSM: TX1RTS
Pin mode bit
1 = Pin is used to request message transmission of TXB1 buffer (on falling edge)
0 = Digital input
bit 0 B0RTSM: TX0RTS
Pin mode bit
1 = Pin is used to request message transmission of TXB0 buffer (on falling edge)
0 = Digital input
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
SID10SID9SID8SID7SID6SID5SID4SID3
bit 7 bit 0
bit 7-0 SID: Standard Identifier bits <10:3>
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