10.3.2 RXD Dominant Timeout (RXD DTO)

All devices have a RXD DTO circuit that prevents a bus stuck dominant fault from permanently driving the RXD output dominant (low) when the bus is held dominant longer than the timeout period t_{RXD_DTO}. The RXD DTO timer starts on a falling edge on RXD (bus going dominant). If no rising edge (bus returning recessive) is seen before the timeout constant of the circuit expires (t_{RXD_DTO}), the RXD pin returns high (recessive). The RXD output is re-activated to mirror the bus receiver output when a recessive signal is seen on the bus, clearing the RXD dominant timeout. The CAN bus pins are biased to the recessive level during a RXD DTO.