Use these drills after completing all topics in ATPG & Pattern Generation. Answer with metric, mechanism, evidence, owner, and regression plan.
[INT][DFT][ATPG-PATTERNS]
Q: Coverage is 98.5% but release is blocked. Why?
A:
Coverage alone does not prove quality; untestable classes, model mix, and tester feasibility may still violate policy.
FOLLOW-UP TRAP: Using one coverage number as signoff.[INT][DFT][ATPG-PATTERNS]
Q: When is adding a new fault model justified late schedule?
A:
When defect risk and product quality needs outweigh added pattern and runtime cost, with explicit owner approval.
FOLLOW-UP TRAP: Always adding model depth by default.METRIC -> MECHANISM -> EVIDENCE -> FIX -> REGRESSIONATPG FLOW
fault model -> constraints -> generation -> simulation -> coverage closure -> signoffState metric, lot/corner context, and pattern tag with every claim.
Treat timing, power, and quality as one signoff problem.
Chasing coverage without legality checks.
Ignoring test-power side effects of pattern changes.
Debugging silicon without reproducible tags.