Patent 7610421 was granted and assigned to Olympus Group on October, 2009 by the United States Patent and Trademark Office.
A bus request control circuit provided in a signal processing circuit having a higher priority in an arbitration circuit includes a request signal transmitting section which transmits a request signal to request a bus right to the arbitration circuit. A request acknowledge signal receiving section receives a request acknowledge signal transmitted from the arbitration circuit in response to the request signal transmitted to the arbitration circuit. Further, the request signal from the request signal transmitting section is transmitted after lapse of a predetermined time since reception of the request acknowledge signal.