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 67
MCP2515
FIGURE 12-8: READ STATUS INSTRUCTION
FIGURE 12-9: RX STATUS INSTRUCTION
SO
SI
SCK
CS
0 23456789101112131415161718192021221
00001010
76543210
instruction
data out
high-impedance
23
don’t care
CANINTF.RX0IF
CANINTFL.RX1IF
CANINTF.TX0IF
CANINTF.TX1IF
CANINTF.TX2IF
TXB2CNTRL.TXREQ
TXB1CNTRL.TXREQ
TXB0CNTRL.TXREQ
76543210
data out
repeat
SO
SI
SCK
CS
0 23456789101112131415161718192021221
00011010
76543210
instruction
data out
high-impedance
23
don’t care
76543210
data out
repeat
2 1 0 Filter Match
000RXF0
001RXF1
010RXF2
011RXF3
100RXF4
101RXF5
110RXF0 (rollover to RXB1)
111RXF1 (rollover to RXB1)
CANINTF.RXnIF bits are mapped to
bits 7 and 6.
7 6 Received Message
00No RX message
01Message in RXB0
10Message in RXB1
11Messages in both buffers*
The extended ID bit is mapped to
bit 4. The RTR bit is mapped to
bit 3.
4 3 Msg Type Received
00Standard data frame
01Standard remote frame
10Extended data frame
11Extended remote frame
* Buffer 0 has higher priority, therefore, RXB0 status is
reflected in bits 4:0.