Arbitrating Requests for Access to a Computer Resource by Ordered Requestors

A method of arbitrating between a plurality of ordered requestors and a shared resource in a computing system, the plurality of requestors being ordered from lowest to highest according to one or more criteria, the method comprising:

• receiving active information indicating which of the plurality of requestors have requested access to the resource in a cycle;
• receiving priority information indicating which of the plurality of requestors have priority in the cycle;
• selecting one of the plurality of requestors that has requested access to the resource based on the active information and the priority information by:
• determining whether there is at least one requestor that has requested access to the resource in the cycle and has priority in the cycle;
• in response to determining that there is at least one requestor that has requested access to the resource in the cycle and has priority in the current cycle, selecting a lowest ordered requestor that has requested access to the resource in the cycle and has priority in the cycle;
• and
• in response to determining that there are no requestors that have requested access to the resource in the cycle and have priority in the cycle, selecting a highest ordered requestor that has requested access to the resource in the cycle;
• and
• outputting information identifying the selected requestor.