{HEAD ~ SBACK1 and SBACK2 signals} 480, 485 are asserted by the central arbitrator circuit of the system bus 110 over {TAIL ~ the bus} 110 
are asserted over
{ HEAD ~ SBACK1 and SBACK2 signals } 480 , 485 are asserted by the central arbitrator circuit of the system bus 110 over { TAIL ~ the bus } 110
HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH REL REL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH REL TAIL TAIL TAIL TAIL TAIL TAIL OTH