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CDC / RDC · All levels

CDC Protocol Verification: Step-by-Step Walkthrough

Step-by-Step Walkthrough for CDC Protocol Verification.

Step-by-step analysis walkthrough

Use this sequence when owning CDC Protocol Verification in a signoff review.

  1. Inspect warning class and severity.

  2. Trace crossing endpoints and domains.

  3. Check protocol/reset assumptions against spec.

  4. Review synchronizer or FIFO implementation detail.

  5. Run focused assertion or formal check.

  6. Draft fix options with risk and schedule impact.

  7. Execute regression and publish closure memo.

Artifacts to collect

  • SVA package, formal liveness report, simulation stress matrix

  • crossing inventory

  • waiver board notes

  • regression report

Decision memo template

diagram
CDC/RDC DECISION MEMO — CDC Protocol Verification
risk class:
mechanism:
evidence:
fix/waiver:
owners: verification lead, formal owner, CDC lead

Reference visuals

Safety + liveness

diagram
SAFETY: no duplicate / no drop
LIVENESS: every req eventually gets ack

Structural clean CDC is necessary, not sufficient.

CDC/RDC deep dive

Protocol correctness is the bridge between structural clean and functional safe.

Concept diagram

diagram
PROTOCOL FLOW

intent -> transport protocol -> synchronization -> destination acceptance

Metric graph

diagram
PROTOCOL ISSUE BURNDOWN

open issues: 20 -> 11 -> 5 -> 0

Reports and artifacts

  • FIFO pointer proofs

  • req/ack liveness

  • pulse miss checks

  • protocol assertions

Mini case study

Async FIFO empty/full logic looked correct until gray decode mismatch appeared during reset overlap.

Debug branches

  • Pointer sync audit

  • formal liveness checks

  • reset interaction review

Senior review question

Ask: what evidence proves this risk is closed for silicon, not just tool-clean?

Key takeaways

  • State crossing class, assumptions, and owner with every issue.

  • Run structural and dynamic regressions after each fix.

Common pitfalls

  • Treating all warnings as equivalent risk.

  • Waiving issues without containment evidence.

  • Skipping reset and reconvergence stress after CDC fixes.

Principal CDC/RDC review addendum

CDC closure requires proving protocol safety and liveness, not only structural synchronizer presence.

Metric: assertion pass rate, liveness coverage, CDC protocol bug escape rate

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