Patent ID: 7664901

Claim:
A data processing apparatus comprising: a shared resource; a plurality of logic elements sharing access to the shared resource; arbitration circuitry, responsive to requests by one or more of said logic elements for access to the shared resource, to perform a priority determination operation to select one of said requests as a winning request; the arbitration circuitry applying an arbitration policy to associate priorities with each logic element, the arbitration policy comprising multiple priority groups, each priority group having a different priority and containing at least one of said logic elements, within each priority group the arbitration circuitry applying a priority ordering operation to attribute relative priorities to the logic elements within that priority group; and the arbitration circuitry being responsive to a predetermined event to re-apply the priority ordering operation within at least one priority group prior to a subsequent performance of the priority determination operation; when performing the priority determination operation, the arbitration circuitry is configured to select as said winning request the one of said requests having the highest priority, where for each request, the priority of that request is determined by the priority of the priority group that contains the logic element issuing that request and the relative priorities attributed to the logic elements within that priority group.