COMMELL MPX-2515 - Manual (Page 5)

Commell MPX-2515 User’s Guide Rev 0100
Taiwan Commate Computer Inc. 5
This status packet can be obtained via issuing an INTERRUPT IN transfer over the
endpoint 3 of the MPX-2515 card. This status packet contains eight bytes per
packet. This section defines each byte of the status packet.
Please be noted that interrupt in transfers can be issued at anytime. MPX-2515
applications are encouraged to retrieve the status packets often in order to check out
the status that the application has concerned.
The following table defines the format of the Status Packet. MPX-2515 application
programmers can also refer to the Microchip MCP2515 data sheet for more
information.
OFFSET BYTE NAME
0 1 READ STATUS INSTRUCTION (return byte)
Bit 7 CANNTF.TX2IF
Bit 6 TXB2CNTRL.TXREQ
Bit 5 CANINTF.TX1IF
Bit 4 TXB1CNTRL.TXREQ
Bit 3 CANINTF.TX0IF
Bit 2 TXB0CNTRL.TXREQ
Bit 1 CANINTFL.RX1IF
Bit 0 CANINTF.RX0IF
1 1 RX STATUS INSTRUCTION (return byte):
Bit 7:6 Receive Message
00: No RX message
01: Message in RXB0
10: Message in RXB1
11: Messages in both buffers
Bit 5 Don't Care
Bit 4:3 Message Type Received
00: Standard data frame
01: Standard remote frame
10: Extended data frame
11: Extended remote frame
Bit 2:1:0 Filter Match
000: RXF0
001: RXF1
010: RXF2
011: RXF3
100: RXF4
101: RXF5
110: RXF0 (rollover to RXB1)
111: RXF1 (rollover to RXB1)
2 1 EFLG - ERROR FLAG
Bit 7 RX1OVR: Receive Buffer 1 overflow flag bit.
Bit 6 RX0OVR: Receive Buffer 0 overflow flag bit.
Bit 5 TXBO: Bus-Off Error flag bit