Device 1, wherein the third sub block includes a selective passage gate of which the input is connected to the output of {HEAD ~ the second sub block} and which is controlled by the output of {TAIL ~ the first sub block} 
Device 1 , wherein the third sub block includes a selective passage gate of which the input is connected to the output of { HEAD ~ the second sub block } and which is controlled by the output of { TAIL ~ the first sub block }
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 HEAD OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL