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ManualsBrandsRENESAS ManualsMicrocontrollers, Microprocessors & QuartzesEmbedded microcontroller LQFP 100 32-Bit 48 MHz I/O number 77
981982983984985986987988989990
V850ES/JG3-H, V850ES/JH3-H CHAPTER 20 CAN CONTROLLER
R01UH0042EJ0500 Rev.5.00 Page 982 of 1513
Aug 12, 2011
20.9 Message Reception
20.9.1 Message reception
All buffers satisfying the following conditions are searched in all the message buffer areas in all the operation modes in
order to store newly receive messages.
• Used as a message buffer
(C0MCONFm.MA0 bit is set to 1.)
• Set as a receive message buffer
(C0MCONFm.MT2 to C0MCONFm.MT0 bits are set to 001B, 010B, 011B, 100B, or 101B.)
• Ready for reception
(C0MCTRLm.RDY bit is set to 1.)
Remark m = 00 to 31
When two or more message buffers of the CAN module receive a message, the message is stored according to the
priority explained below. The message is always stored in the message buffer with the highest priority, not in a message
buffer with a low priority. For example, when an unmasked receive message buffer and a receive message buffer linked
to mask 1 have the same ID, the received message is not stored in the message buffer linked to mask 1 that has not
received a message, even if a message has already been received in the unmasked receive message buffer. In other
words, when a condition has been set to store a message in two or more message buffers with different priorities, the
message buffer with the highest priority always stores the message; the message is not stored in message buffers with a
lower priority. This also applies when the message buffer with the highest priority is unable to receive and store a
message (i.e., when the DN bit = 1 indicating that a message has already been received, but rewriting is disabled because
the OWS bit = 0). In this case, the message is not actually received and stored in the candidate message buffer with the
highest priority, but neither is it stored in a message buffer with a lower priority.
Priority Storing Condition If Same ID Is Set
DN bit = 0 1 (high) Unmasked message buffer
DN bit = 1 and OWS bit = 1
DN bit = 0 2 Message buffer linked to mask 1
DN bit = 1 and OWS bit = 1
DN bit = 0 3 Message buffer linked to mask 2
DN bit = 1 and OWS bit = 1
DN bit = 0 4 Message buffer linked to mask 3
DN bit = 1 and OWS bit = 1
DN bit = 0 5 (low) Message buffer linked to mask 4
DN bit = 1 and OWS bit = 1