Patent ID: 7302510

Claim:
A fair hierarchical arbiter comprising: a first arbitration mechanism coupled to at least one first requestor that produces requests, the first arbitration mechanism outputting first winning requests on a first winning request output, and first valid request bits on a first valid request bits output, the first valid request bits conveying information as to which particular requestor in the at least one first requestor originated a current request driven on the first winning request output; and a second arbitration mechanism coupled to the first winning request output, and to the first valid request bits, the second arbitration mechanism further coupled to at least one second requestor, the second arbitration mechanism outputting second winning requests on a second winning request output; wherein the first valid request bits are used by the second arbitration mechanism to ensure requests driven on the second winning request output are requests originated by the at least one first requestor and the at least one second requestor in a round robin order of all requestors in a total set of requestors consisting of the at least one first requestor and the at least one second requestor.