Datasheet

 2003-2012 Microchip Technology Inc. DS21801G-page 69
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.