A semiconductor circuit includes a first pad, a second pad, swapping circuit, and an internal circuit. The internal circuit receives a first external signal and a second external signal, and generates a first internal signal and a second internal signal. Based on master information and swapping information, the swapping circuit couples the internal circuit to one of first and second pads to provide a path through which the first internal signal is output and a path through which the first external signal is received, and couples the internal circuit to the other of the first and second pads to provide a path through which the second internal signal is output and a path through which the second external signal is received.