Multilayer Arbitration for Access to Multiple Destinations

A system comprising:

• a shared resource;
• a plurality of master devices coupled to access the shared resource;
• wherein each master device provides a priority value along with an access request;
• a background master coupled to the shared resource, wherein the background master is configured to periodically access the shared resource;
• an arbiter coupled to the plurality of master devices and to the background master, wherein the arbiter is configured to perform an arbitration contest with fairness and to award the winner of the arbitration contest access to the shared resource;
• and
• wherein the arbiter is configured to override the arbitration contest and award the background master access to the shared resource each time the background master requests access.

A digital system, comprising:

• a shared resource;
• a plurality of master devices coupled to access the shared resource;
• a background master coupled to the shared resource, wherein the background master is configured to periodically access the shared resource;
• means for assigning a priority value to each of the plurality of requestors;
• means for performing a multilayer arbitration contest to resolve each conflict in transaction requests to the shared resource, wherein a requester of the plurality of requesters having a highest priority value does not always win an arbitration contest;
• means for overriding an arbitration contest whenever the background requester initiates a transaction request, such that the background requester always wins the overridden arbitration contest;
• and
• means for accessing the shared resource by the winner of each arbitration contest.