In a write/read mode, data is transited from an input/output buffer via the transition circuit to an input of the write amplifier or from an output of the sense amplifier via {HEAD ~ the transition circuit} to {TAIL ~ an input/output buffer} 
In a write / read mode , data is transited from an input / output buffer via the transition circuit to an input of the write amplifier or from an output of the sense amplifier via { HEAD ~ the transition circuit } to { TAIL ~ an input / output buffer }
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 OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL