Patent ID: 7707342

Claim:
An access arbiter apparatus that arbitrates access requests respectively issued from a plurality of request origins with respect to a common resource, comprising: a request checking unit that checks whether an access request signal is present; a plurality of priority tables that define priority levels of the request origins, the priority tables for which an order of employment is defined; a arbitration control unit that controls arbitration, when a plurality of access request signals are present, determines for each access request, whether the access request is to be accepted based on the priority tables; and a response signal issuing unit that issues a response signal to a request origin of which the access request has been determined to be accepted by the arbitration control unit, wherein the arbitration control unit employs, among the priority tables, a priority table next to a previous priority table that is employed in last arbitration, and determines whether to accept each of the access requests based on priority levels defined in the employed priority table, wherein a number of the plurality of priority tables is set to equal to a number of the plurality of request origins when the number of the plurality of request origins is even, and the number of the plurality of priority tables is set to twice the number of the plurality of request origins when the number of the plurality of request origins is odd, and wherein the priority level of each of the request origins is defined such that a rate of a higher priority level of each of the request origins is substantially equal for each of the request origins, and a rate of a lower priority level of each of the request origins is substantially equal for each of the request origins.