The first TAP controller enters {HEAD ~ an idle state} and its control signal is gated to hold {TAIL ~ the first TAP controller} in the idle state until the second TAP controller enters the idle state 
The first TAP controller enters { HEAD ~ an idle state } and its control signal is gated to hold { TAIL ~ the first TAP controller } in the idle state until the second TAP controller enters the idle state
OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH