57.7.11.8 Transmit FIFO Lock

• LIN Mode:

If a frame is aborted using the Abort LIN Transmission bit (FLEX_US_CR.LINABT), a lock is set on the Transmit FIFO, preventing any new frame from being sent until it is cleared. This allows clearing the FIFO if needed, resetting DMA channels, etc., without any risk.

• LON Mode:

If a frame is terminated early due to collision, a lock is set on the Transmit FIFO preventing any new frame from being sent until it is cleared. This allows clearing the FIFO if needed, resetting DMA channels, etc., without any risk.

The TXFLOCK bit in the USART FIFO Event Status register (FLEX_US_FESR) is used to check the state of the Transmit FIFO lock.

The Transmit FIFO lock can be cleared by setting FLEX_US_CR.TXFLCLR to ‘1’.