A hand shake type control circuit for controlling {HEAD ~ a data transfer circuit} according to {TAIL ~ the status} of a data transfer request signal 
according to
A hand shake type control circuit for controlling { HEAD ~ a data transfer circuit } according to { TAIL ~ the status } of a data transfer request signal
OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH