DEVICE AND METHOD FOR ARBITRATING BUS USE REQUEST

摘要

PROBLEM TO BE SOLVED: To make the circuit scale small by providing a mechanism which does not allow a bus to be used at a bus use request made by a bus master module which is already given bus use permission while all bus master modules are given bus use permission. SOLUTION: When a bus use request hold signal that a bus use request hold part BRLAT1 holds is ceased, the bus use request hold part BRLAT1 asserts an unmasking signal SMCLR and a bus use request mask part BRMS1 having received it unmasks all masked bus use request hold signals SBREQ. If the bus use request hold part BRLAT1 does not assert a bus use request which is masked so far as a bus use request signal as a result of the unmasking, it is considered that the bus use request is given bus use permission within the period and the process is ended.