Abstract: A receiver circuit is connected to a differential serial bus having first and second signal conductors. The receiver circuit includes a fault detection circuit which generates a difference signal representing a difference between a first signal on the first conductor and a second signal on the second conductors. A comparing circuit includes a plurality of comparators for comparing the difference signal, the first signal and the second signal to predetermined voltage levels. The comparing circuit also includes a plurality of logic units coupled to outputs of the comparators. A signal select circuit has a pair of inputs coupled to the first and second conductors, logic inputs coupled to logic outputs of the comparing circuit, and a signal output. The signal select circuit and the comparing circuit cooperate to control communication of the first and second conductors with the signal output as a function of fault conditions on the first and second conductors.