A resume signal hold circuit holds an assertion of a resume signal instructed while the circuit block is in a stand-by mode. A resume signal mask circuit is provided between the circuit block and the resume signal hold circuit, and masks the signals while the circuit block is in the stand-by mode so that no signal can be input to the circuit block. A power saving control circuit causes the resume signal hold circuit to hold the assertion of the event signal and causes the resume signal mask circuit to mask the signals while the circuit block is in a stand-by mode. The power saving control circuit also causes the resume signal hold circuit to cancel the holding of the assertion of the resume signal after the completion of the resume setting of the circuit block and cancelling of the signal masking by the resume signal mask circuit.