operating the first clock signal and generating at least one clock signal whose phase is different than {HEAD ~ a phase} of {TAIL ~ the first clock signal} 
operating the first clock signal and generating at least one clock signal whose phase is different than { HEAD ~ a phase } of { TAIL ~ the first clock signal }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL