A read write circuit has two data lines {HEAD ~ each} of which is associated with {TAIL ~ a read circuit} 
is associated with
A read write circuit has two data lines { HEAD ~ each } of which is associated with { TAIL ~ a read circuit }
OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD OTH OTH REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL