Formal Verification · All levels
Implication Operators, Clocking, and Reset Gating: Reports and Metrics
Reports and Metrics for Implication Operators, Clocking, and Reset Gating.
Reports and metrics
Reports and Metrics for Implication Operators, Clocking, and Reset Gating is anchored on non-vacuous closure rate, counterexample turnaround, and residual-risk trend by requirement class. Convert outcomes into assumption-aware, evidence-backed actions.
A useful report explains why closure quality moved, not only that status changed.
Evidence matrix
EVIDENCE MATRIX - Implication Operators, Clocking, and Reset Gating
+-----------------------------+--------------------------------+--------------------------------+---------------------------+
| Evidence | Tells you | Does not prove | Next action |
+-----------------------------+--------------------------------+--------------------------------+---------------------------+
| property status by class | closure shape by requirement | model realism | pair with cover reachability |
| vacuity and trigger checks | assertion meaningfulness | full legal-path exploration | inspect assumptions |
| counterexample traces | concrete divergence path | complete bug-space closure | classify and replay |
| assumption audit trail | model boundary confidence | implementation correctness | review spec traceability |
| before/after trend packet | mitigation movement quality | long-window stability | run broader matrix |
+-----------------------------+--------------------------------+--------------------------------+---------------------------+Track non-vacuous closure rate, counterexample turnaround, and residual-risk trend by requirement class by requirement class and risk tier.
Include assumption and tool metadata in every report header.
Correlate status with vacuity and cover reachability movement.
Call out contradictory evidence explicitly.
Formal deep dive
SVA scales when temporal intent, clock sampling, and reset gating are precise enough to be replayed and reviewed.
Concept diagram
SVA INTENT CHAIN
timing contract -> sequence composition -> property implication -> sampled failure traceMetric graph
ASSERTION QUALITY SIGNALS
non-vacuous hit rate ████████
clock/reset mismatches ████
false-positive churn ███Metrics and artifacts to collect
assertion trigger hit-rate
implication timing mismatch bucket
reset-window noise ratio
assertion decomposition quality score
Mini case study
A protocol failure vanished after correcting `|->` vs `|=>` semantics and reset masking boundaries.
Debug branches
Confirm antecedent trigger at sampled clock edges.
Verify implication operator matches protocol timing contract.
Split monolithic properties into stage-local checks.
Senior review question
Ask: which requirement intent is proven, under which assumptions, and what residual risk remains?
Key takeaways
Tie each proof claim to assumption boundaries and reachability evidence.
Prefer minimal reversible fixes and preserve legal behavior visibility.
Common pitfalls
Treating runtime reduction as proof-quality improvement without audits.
Declaring closure while critical covers remain unreachable.
Using broad waivers instead of first-divergence root-cause ownership.
Report interpretation
Report status with vacuity, cover reachability, and assumption influence side by side.
Promote only when trend data supports reproducible closure behavior.