BAT32G1x9 user manual | Chapter 22 CAN control
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Rev.1.02
22.9 Message reception
22.9.1
Message reception
In all operating modes, the full packet buffer area is analyzed to find the appropriate buffer to store the
newly received packets. All message buffers that meet the following criteria are included in the evaluation
(RX search process):
-
Packet cache used
(The MA0 bit of CnMCONFm is 1).)
-
Is set up as a cache for receiving packets
(The MT[2:0] bit of CnMCONFm is set to 001B, 010B, 011B, 100B, or101B.).
-
Ready to receive
(The RDY bit of CnMCTRLm is set to 1).
When there are two or more packet caches to receive a message, the message is stored in a higher
priority cache. For example, when an unmasked receive packet buffer and a receive packet buffer linked to
mask 1 have the same ID, the received packet is not stored in the packet buffer linked to mask 1, even if the
packet buffer has not yet received the packet and the message is already in the unmasked receive packet
buffer. In other words, when set to store messages in two or more packet buffers with different priorities, the
message buffer with the highest priority always stores messages; Messages are not stored in lower priority
packet buffers. This also applies when the message buffer with the highest priority cannot receive and store
messages (i.e. when DN=1 indicates that a message has been received, but because of OWS=0, overrides
are disabled). In this case, the message is not actually received and stored in the candidate buffer with the
highest priority, but also not in the lower priority packet buffer.
Priority
Storage in case the same ID is set
1 (high).
There is no blocked packet caching
DN=0
DN=1 and OWS=1
2
Link to packet cache for block 1
DN=0
DN=1 and OWS=1
3
Link to the packet cache for block 2
DN=0
DN=1 and OWS=1
4
Links to the packet cache for block 3
DN=0
DN=1 and OWS=1
5 (low).
Link to packet cache for block 4
DN=0
DN=1 and OWS=1
Note m= 0
to
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