SVA Sequences and Properties: Review Checklist

Review checklist

Review Checklist for SVA Sequences and Properties is anchored on non-vacuous closure rate, counterexample turnaround, and residual-risk trend by requirement class. Convert outcomes into assumption-aware, evidence-backed actions.

• Requirement scope and risk tier are explicit.

• Assumption model is traceable and reviewed.

• Mechanism classification is evidence-backed.

• Owner, rollback trigger, and validation matrix are documented.

• Owners signed: formal verification owner, rtl owner, SystemVerilog Assertions (SVA) owner.

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 trace

Metric 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.

Principal formal review addendum

SVA Sequences and Properties should be reviewed as a requirement-evidence workflow, not a single status report.

Use non-vacuous closure rate, counterexample turnaround time, and requirement-level residual risk trend as the monitoring lens and formal closure packet: assumptions audit, proof status matrix, counterexample classification, and requirement traceability as closure proof.

SVA quality comes from temporal precision, correct sampling semantics, and disciplined vacuity control. Strong teams preserve legal reachability while improving convergence.