The protocol supports a memory subsystem which queues memory requests such that the processor, or {HEAD ~ cache memory} requesting data, relinquishes {TAIL ~ the shared bus} after making its request 
relinquishes
The protocol supports a memory subsystem which queues memory requests such that the processor , or { HEAD ~ cache memory } requesting data , relinquishes { TAIL ~ the shared bus } after making its request
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH