a first logic unit which logically operates {TAIL ~ the first data} and {HEAD ~ the first transfer control signal}, and outputs the result of the logical operation 
a first logic unit which logically operates { TAIL ~ the first data } and { HEAD ~ the first transfer control signal } , and outputs the result of the logical operation
OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH