38.5.9.2 Three Retransmission Attempts

In case an error is detected during transmission, the CAN FD Protocol module will decrement the number of remaining attempts and try to retransmit the message the next time the bus is Idle. In case arbitration is lost, the number of remaining attempts will not change. If all retransmission attempts are exhausted, TXREQ will be cleared and TXATIF in CxFIFOSTAy or CxTXQSTA will be set.

Before retransmitting the message, the transmit priority will be recalculated. The retransmission attempts will be reinitialized if a different TX FIFO or TXQ is selected for transmission, or if a message is received after the last transmission attempt.