CDC Review Gate: Interview Drills

Interview drills

Interview Drills for CDC Review Gate focuses on gate pass rate, late-stage CDC churn, review defect leakage. The goal is to convert issue observations into mechanism-backed closure decisions.

PROMPT
You see gate pass rate, late-stage CDC churn, review defect leakage in CDC Review Gate. Explain root cause and signoff decision.

STRONG ANSWER
1. Names crossing/reset class and context.
2. Explains Gate reviews align RTL, verification, and signoff evidence before integration milestones to avoid endgame metastability surprises.
3. Requests review checklist, gate scorecard, escalation log.
4. Chooses fix/waiver/escalation with regression plan.

WEAK ANSWER
Lists tool commands or generic advice without mechanism and risk framing.

Diagram to draw on whiteboard

Review gate criteria

Gate inputs:
  - zero critical unowned CDC issues
  - formal/sim evidence for protocol crossings
  - waiver aging below threshold

Debug tree to narrate

ROOT-CAUSE TREE — CDC Review Gate

crossing failure observed
        |
   reproducible?
     /        \
   no          yes
   |            |
stress mode   classify issue
expansion       /      |      \
            synchronizer protocol reset/reconvergence
                 |         |           |
            MTBF fit    liveness    release ordering

CDC/RDC deep dive

Signoff is an evidence governance problem across teams.

Concept diagram

CDC SIGNOFF LOOP

analysis -> triage -> fix/waive -> review gate -> dashboard

Metric graph

CRITICAL OPEN COUNT

week1 34
week2 22
week3 10
week4 0

Reports and artifacts

• critical by owner

• waiver quality

• review gate status

• closure trend

Mini case study

Pass rates improved while critical waivers aged out of policy; dashboard exposed hidden risk.

Debug branches

• Separate quality from quantity metrics

• enforce waiver expiry

• run gate checklists consistently

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

Gate reviews align RTL, verification, and signoff evidence before integration milestones to avoid endgame metastability surprises.

Metric: gate pass rate, late-stage CDC churn, review defect leakage