38.3.2.2 Protocol Exception Disable

The negative edge between the FDF bit and the “reserved bit” in CAN FD frames is important for the calculation of the transceiver delay and for hard synchronization. Therefore, if the “reserved bit” following the FDF bit is detected recessive, the CAN FD Protocol Module will treat this as a form error. This is called, “Protocol Exception Event Detection Disabled” and is configured by setting the PXEDIS bit. The Protocol Exception Event Detection Disabled can be enabled by clearing the PXEDIS bit. As a reaction to the protocol exception event, the error counters are not changed, hard synchronization is enabled, the module sends recessive bits and enters the Bus Integration state.