50.8.3.3 Remote Frame Handling

The producer/consumer model is an efficient means to handle broadcast messages. The push model allows a producer to broadcast messages; the pull model allows a customer to request messages.

In Pull mode, a consumer transmits a remote frame to the producer. When the producer receives a remote frame, it sends the answer accepted by one or many consumers. Using transmit and receive mailboxes, a consumer must dedicate two mailboxes, one in Transmit mode to send remote frames, and at least one in Receive mode to capture the producer’s answer. The same structure is applicable to a producer: one reception mailbox is required to get the remote frame and one transmit mailbox to answer.

Mailboxes can be configured in Producer or Consumer mode. A lonely mailbox can handle the remote frame and the answer. With 8 mailboxes, the CAN controller can handle 8 independent producers/consumers.