
Registers C2GMARi, C2GMBRi, C2LMARi, and C2LMBRi (i = 0 to 4) are used for acceptance filtering.
Using these registers, uses are able to select which messages to receive.
The C2GMARi register determines whether IDs in the message slots 0 to 15 are checked or not. The C2GMBRi
register determines whether IDs in the message slots 16 to 29 are checked or not. The C2LMARi register
determines whether ID in the message slot 30 is checked or not. The C2LMBRi register determines whether ID
in the message slot 31 is checked or not.
When the bit in registers C2GMARi, C2GMBRi, C2LMARi, and C2LMBRi is set to 0, the corresponding
bits (ID bit) in the CAN2 message slot j’s (j = 0 to 31) standard ID0, standard ID1, and extended ID0 to
extended ID2 is masked in acceptance filtering. (The corresponding bit is assumed to have a matching ID.)
When the bit in registers C2GMARi, C2GMBRi, C2LMARi, and C2LMBRi is set to 1, the corresponding
ID bit is compared with a received ID in acceptance filtering. When the received ID matches the ID set in
the message slot j, the receive data is stored into the message slot having the matched ID.
NOTES:
1. Change the C2GMARi register while none of the message slots 0 to 15 has a receive request.
2. Change the C2GMBRi register while none of the message slots 16 to 29 has a receive request.
3. Change the C2LMARi register while the message slot 30 has no receive request.
4. Change the C2LMBRi register while the message slot 31 has no receive request.
5. When there are two or more receive message slots which have the matched ID with the received message,
the received message is stored into the smallest-numbered message slot.
filtering.
Figure 23.29
Mask Register and Message Slot
Figure 23.30
Acceptance Filtering
Message slot 16
to
Message slot 29
i = 0 to 4
Message slot 30
Message slot 31
C2GMBRi register
C2LMARi register
C2LMBRi register
Message slot 0
to
Message slot 15
C2GMARi register
Receive message ID
ID set in the
message slot
C2GMAR register, C2GMBR register
C2LMAR register, C2LMBR register
Value of the mask bit
0: Whether a receive message ID is matched
is handled as "don't care" (or masked)
1: Whether a receive message ID is matched
is verified
Acceptance verify signal
0: Receive message is ignored
(Message is stored into no message slot)
1: Receive message is stored into a
message slot having a matched ID
Acceptance verify signal
For Standard ID
Standard ID0
Standard ID1
Standard ID10
SID0
SID0M
SID1M
SID10M
SID1
SID10