A system includes a multiplexer, an input/output (I/O) pin, a logic circuit, and a control register. The multiplexer has multiple inputs, an output, and a selection input. The logic circuit is coupled between the multiplexer and the I/O pin. The logic circuit hays a first input. The control register includes first and second bit fields corresponding to the I/O pin. The first bit field is coupled to the selection input of the multiplexer, and the second bit field is coupled to the first input of the logic circuit.