While data cannot be transmitted down a scan chain through a stuck-at fault
location, data in properly operating latches downstream of the stuck-at fault location
can be shifted down the chain. By varying operating parameters, such as power supply
and reference voltages, clock timing patterns, temperature and timing sequences,
one or more latches down the SRL chain from the stuck-at fault location may be
triggered to change state from the stuck-at fault value. The SRL chain is then
operated to shift data out the output of the SRL chain. The output is monitored
and any change in value from the stuck-at state is noted as identifying all good
latch positions to end of the chain. The process is repeated: varying each of the
selected operating parameters until the latch position following the stuck-at fault
latch is identified.