Patent ID: 7685346

Claim:
An apparatus comprising: a plurality of grant counters each associated with an agent of a system that is to request access to a resource, wherein each of the plurality of grant counters is to be decremented when the corresponding agent is granted access, and wherein a value of the grant counter is to be updated to a predetermined maximum count for the corresponding agent upon an access grant to the corresponding agent when the value is zero; a demotion-based priority list coupled to the plurality of grant counters to maintain an active arbitration priority list, the priority list including a shift register; and a grant generator coupled to the priority list to perform arbitration based on status of the priority list and to generate a grant signal; wherein (a) the corresponding grant counter is to be reset to the predetermined maximum count after the grant signal is provided for the agent, and without expiration of a fixed arbitration window; (b) the priority list is to demote an agent, when the value of the corresponding grant counter is at zero and a grant signal is provided for the agent, promote other agents in the priority list when the agent is demoted, and include a first plurality of multiplexors, each to receive a grant count expiration from the plurality of grant counters, and (c) a first of the multiplexors and a first of the grant counters are both associated with a first agent of the system.