DenseChip

Formal Verification · All levels

Formal Verification Foundations

Core foundations of formal property verification: exhaustive proof versus simulation, safety and liveness property design, cone-of-influence reduction, and practical FPV tool-flow setup with sound constraints and convergence strategy.

Section goal

Core foundations of formal property verification: exhaustive proof versus simulation, safety and liveness property design, cone-of-influence reduction, and practical FPV tool-flow setup with sound constraints and convergence strategy.

How to study this section

  1. Start with each topic hub and restate the requirement intent in your own words.

  2. Use reports and debug pages to classify first divergence accurately.

  3. Practice worked examples and interview drills with fixed run metadata.

  4. Close with checklist and residual-risk framing before signoff claims.

Topics

  1. formal-vs-simulation/ - Formal vs Simulation: Exhaustive Proof and Stimulus-Based Search

  2. properties-and-assertions/ - Properties and Assertions: Safety, Liveness, and Sound Modeling

  3. cone-of-influence/ - Cone of Influence (COI): State-Space Reduction with Intent Preservation

  4. formal-tool-flow/ - Typical FPV Tool Flow: Setup, Constraints, Run, Debug, and Closure

Related topics

Formal deep dive

FPV foundations are reliable only when assumptions, reset semantics, and requirement intent are explicitly modeled and audited.

Concept diagram

diagram
FPV FOUNDATION LOOP

requirements -> property set -> assumptions and reset model -> prove/fail traces -> closure audit

Metric graph

diagram
FOUNDATION HEALTH

vacuous passes         ████
reachable proofs       ███████
inconclusive backlog   █████
reopened properties    ███

Metrics and artifacts to collect

  • assumption traceability matrix

  • vacuity and reachability status

  • proof core relevance summary

  • counterexample classification trend

Mini case study

A green-looking run was invalidated after legal-mode covers failed, exposing assumptions that removed realistic traffic.

Debug branches

  • Validate requirement-to-property mapping before tuning runtime.

  • Check legal scenario reachability after every assumption change.

  • Classify first divergence as model issue or RTL bug.

Senior review question

Ask: which requirement intent is proven, under which assumptions, and what residual risk remains?

Practice this lesson