Scoreboard & Checker Strategy: Review Checklist

Review checklist

Review Checklist for Scoreboard & Checker Strategy focuses on false fail rate, escaped bug count, response match latency. The goal is to connect the observable symptom to protocol mechanism, ownership, and regression risk.

• Spec revision and implemented feature subset are named.

• Clock/reset and CDC assumptions are reviewed.

• Traffic classes, IDs/tags, ordering, and outstanding limits are documented.

• VIP/compliance coverage maps back to requirements.

• Performance metric and debug artifact are stored with the signoff note.

• Owners signed: verification owner, formal owner, RTL owner.

Sign-off ownership

OWNERSHIP MAP — Scoreboard & Checker Strategy

evidence type        owner who reads it
-----------------    ---------------------------
waveform/RTL        verification owner
spec/VIP            formal owner
firmware/system     RTL owner

Rule: every metric must have a named owner before a review starts.

Protocol deep dive

Verification closes the gap between 'works in directed test' and 'legal under all stressed traffic'.

Concept diagram

VERIFICATION CLOSURE LOOP

spec clause -> test -> assertion -> coverage -> waiver -> signoff
                  ^                           |
                  +--------- gap found --------+

Metric graph

COVERAGE vs ESCAPE RATE

escapes
  |*
  | *
  |  *
  |   **  <- knee: more random helps
  |     ****
  +----------------> constrained-random depth

Metrics and artifacts to collect

• compliance pass rate

• coverage closure

• scoreboard mismatch rate

• assertion fire count

• waiver log

Mini case study

Block passed VIP compliance but chip failed: system test omitted cross-master ID reuse through a bridge. Scoreboard key did not include upstream port ID.

Debug branches

• If VIP pass but silicon fail, check integration assumptions.

• If scoreboard noisy, fix key (ID+port+addr).

• If coverage plateau, add compliance gap analysis not more repeats.

Senior review question

Ask: what is the first transaction that deviates, and which spec rule does it test?

Key takeaways

• Connect every protocol claim to a transaction identity and measurable metric.

• Store the artifact (waveform, log, counter) next to every signoff decision.

Common pitfalls

• Debugging timeouts without finding the first bad transaction.

• Quoting peak bus width without payload efficiency and retry overhead.

• Treating VIP compliance as a substitute for system integration replay.

Principal review addendum

Re-read Scoreboard & Checker Strategy against one concrete product workload, not a synthetic directed test.

scoreboards correlate requests and responses while assertions check local temporal rules and illegal combinations.