A semiconductor device which has an internal circuit for performing a
circuit operation corresponding to a signal inputted or outputted through
an input/output interface circuit adapted to a serial bus. The
semiconductor device has a non-volatile storage circuit for storing
identification data. Internal identification data stored in the
non-volatile storage circuit is compared with external identification data
included in an input signal supplied through the serial bus by a
comparator circuit. A control circuit is responsive to a match detecting
signal generated by the comparator circuit to perform a circuit operation
corresponding to an input signal subsequently supplied through the serial
bus to change the internal identification data stored in the non-volatile
storage circuit.
