Multi-processor system including priority arbitrator for arbitrating request issued from processors

In a multi-processor system, a priority arbitrator receives a request issued from each of processors, and arbitrates conflicts occurred among the requests. The requests derived from the respective processors are inputted via selectors (410) to fixed priority arbitrating circuits (420.) Only one request is selected by the fixed priority arbitrating circuit (420,) and the selected request is held in an output register (430.) The pending request is detected by an AND circuit (450,) and the detection result is held in a pending register (410.) When there is such a request held in the pending register, the subsequent request is not selected by the selector (410.) The priorities of the plural fixed priority arbitrating circuits (420) within the multi-processor system may be made different from each other, depending upon the use conditions of the multi-processor system.