The CAN controller provides 32 individual receive message buffers. Each one has its own message filter mask. Automatic reply to RTR messages is supported. If a message is accepted in a receive buffer, its MsgAv flag is set. The message remains valid as long as MsgAv flag is set. The master CPU has to reset the MsgAv flag to enable receipt of a new message. The following figure shows the overall block diagram of the receive message buffers.
Figure 1. Receive Message Buffers
