Datasheet

MCP2515
DS20001801J-page 70  2003-2019 Microchip Technology Inc.
FIGURE 12-8: READ STATUS INSTRUCTION
FIGURE 12-9: RX STATUS INSTRUCTION
SO
SI
SCK
CS
0 2 3 4 5 6 7 8 9 101112131415161718192021221
00001010
76543210
Instruction
Data Out
High-Impedance
23
Don’t Care
RX0IF (CANINTF[0])
RX1IF (CANINTF[1])
TX0IF (CANINTF[2])
TX1IF (CANINTF[3])
TX2IF (CANINTF[4])
TXREQ (TXB2CNTRL[3])
TXREQ (TXB1CNTRL[3])
TXREQ (TXB0CNTRL[3])
7654321 0
Data Out
Repeat
SO
SI
SCK
CS
0 23456789101112131415161718192021221
00011010
76543210
Instruction
Data Out
High-Impedance
23
Don’t Care
7654321 0
Data Out
Repeat
2 1 0 Filter Match
000RXF0
001RXF1
010RXF2
011RXF3
100RXF4
101RXF5
110RXF0 (rollover to RXB1)
111RXF1 (rollover to RXB1)
RXnIF (CANINTF) 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].