INTERFACE CIRCUIT CAPABLE OF PERFORMING SELF TEST

An interface circuit capable of performing a self test is provided to test jitter tolerance without using test equipment. A test circuit(340) generates a parallel test signal. A jitter generator(310) adds jitter to the parallel test signal. A serial converter(320) converts the jitter-added parallel test signal into a serial signal. A parallel converter(330) converts the serial signal outputted from the serial converter into a parallel output signal. The test circuit judges whether the parallel test signal coincides with the parallel test signal outputted from the parallel converter.