A system and method for protecting the values stored in a BISR repair block and,
optionally, debugging the BISR repair logic without altering normal test flow is
implemented by a circuit including a plurality of soft latches within the BISR
repair block, the soft latches being coupled together to form a BISR scan chain
for holding BISR repair information. A chip level scan enable signal and a scan
hold control signal cooperate to control connection of the BISR scan chain to other
scan chains during a scan test, so that the BSR repair information is held within
the soft latches. A diagnose enable signal cooperating with the chip level scan
enable signal and the scan hold control signal for enabling debugging of logic
connecting the BISR scan chains.
