US Patent 7904626 Arbiter and arbitration method of multiple data accesses

There is provided a technique which reduces an average processing time of low-priority accesses with suppressing an average delay increase of a high-priority access processing even in a case where high-priority access request and a low-request access request are simultaneously generated to a shared access processing unit and high-priority accesses are continuously generated. And, there is provided an access arbitration equipment comprising: an issued access request retention unit; a first interval determination circuit; and a second interval determination circuit. In a case where the first interval determination circuit determines that an interval is generated between an issued access processing and a most prior access processing and a second interval determination circuit determines that no interval is generated between the issued access processing and a second-prior access request, the priority order of the most prior access request and the second-prior access request is changed.