R01UH0823EJ0100 Rev.1.00
Page 1269 of 1823
Jul 31, 2019
RX23W Group
36. CAN Module (RSCAN)
Figure 36.5
Acceptance Filter Function
(2) DLC Filter Processing
When the GCFGL.DCE bit is set to 1 (DLC check is enabled), DLC filter processing is added to messages that passed
through the acceptance filter processing. When the DLC value in a message is equal to or larger
than the DLC value set in the receive rule, the message passes through the DLC filter processing.
When a message has passed through the DLC filter processing with the GCFGL.DRE bit set to 0 (DLC replacement is
disabled), the DLC value in the received message is stored in the buffer. In this case, all the data bytes in the received
message are stored in the buffer.
When a message has passed through the DLC filter processing with the GCFGL.DRE bit set to 1 (DLC replacement is
enabled), the DLC value in the receive rule is stored in the buffer instead of the DLC value in the received message. In
this case, a value of 00h is written to data bytes that are larger than the DLC value in the receive rule.
When the DLC value in the received message is smaller than that in the receive rule, the message does not pass through
the DLC filter processing. In this case, the message is not stored in the receive buffer or the FIFO buffer and the
GERFLL.DEF flag becomes 1 (a DLC error is present).
(3) Routing Processing
Messages that passed through the acceptance filter processing and the DLC filter processing are stored in receive
buffers, receive FIFO buffers, or transmit/receive FIFO buffers (set to receive mode). Message storage destination is set
by the GAFLPLj.GAFLRMV, GAFLRMDP[6:0], GAFLFDP4, GAFLFDP1, and GAFLFDP0 bits. Messages that passed
through the acceptance filter processing and the DLC filter processing can be stored in up to two buffers.
(4) Label Addition Processing
It is possible to add 12-bit label information to messages that passed through the filter processing and store them in
buffers. This label information is set in the GAFLPHj.GAFLPTR[11:0] bits.
(5) Mirror Function Processing
The mirror function allows reception of messages transmitted from the own CAN node. The mirror function is made
available by setting the GCFGL.MME bit to 1 (mirror function is enabled).
When the mirror function is in use, receive rules for which the GAFLIDHj.GAFLLB bit is set to 0 are used for data
processing when receiving messages transmitted from other CAN nodes. When receiving messages transmitted
from the own CAN node, receive rules for which the GAFLIDHj.GAFLLB bit is set to 1 are used for data processing.
ID value in
received message
GAFLIDHj, GAFLIDLj
(receive rule entry register jAH/AL)
GAFLMHj, GAFLMLj
(receive rule entry register jBH/BL)
GAFL
IDE
GAFL
RTR
GAFLID
GAFL
IDEM
GAFL
RTRM
GAFLIDM
Acceptance
determination signal
Mask bit value
0: Bits are not compared.
1: Bits are compared.
Acceptance determination signal
0: Does not pass the acceptance filter processing.
(Not stored in the buffer)
1: Passes the acceptance filter processing.
GAFLIDE, GAFLRTR, GAFLID: Bits in the GAFLIDHj and GAFLIDLj registers
GAFLIDEM, GAFLRTRM, GAFLIDM: Mask bits in the GAFLMHj and GAFLMLj registers