{TAIL ~ a second counter} receiving an output of said second multiplexer and outputting {HEAD ~ a second count signal}, 
{ TAIL ~ a second counter } receiving an output of said second multiplexer and outputting { HEAD ~ a second count signal } ,
TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH