{HEAD ~ The data bus} grant {TAIL ~ line} to the memory controller is overloaded to use it as a back pressure, get off the bus signal as well as a normal data bus grant line 
grant
{ HEAD ~ The data bus } grant { TAIL ~ line } to the memory controller is overloaded to use it as a back pressure , get off the bus signal as well as a normal data bus grant line
HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH