{HEAD ~ An arbitration method} and mechanism assigning {TAIL ~ priority} to one of a combination of requesters 
assigning
{ HEAD ~ An arbitration method } and mechanism assigning { TAIL ~ priority } to one of a combination of requesters
HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH REL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH