CDC/RDC Whiteboard Framework: Worked Example

Worked example

Worked Example for CDC/RDC Whiteboard Framework focuses on problem decomposition quality, mechanism-first answer quality. The goal is to convert issue observations into mechanism-backed closure decisions.

A milestone review shows problem decomposition quality, mechanism-first answer quality. Teams disagree on severity. The right move is to isolate one representative issue, prove mechanism class, and decide fix or waiver with explicit residual risk.

Crossing under inspection

CROSSING FLOW — CDC/RDC Whiteboard Framework

source clock domain -> launch signal -> crossing structure -> destination sample
      |                    |                 |                    |
   source FF           protocol           sync / fifo         destination FF

Key metric: problem decomposition quality, mechanism-first answer quality

Interview whiteboard shape

intent -> crossing type -> failure mode
      -> evidence -> fix -> regression -> signoff

1. Capture warning, waveform, and owning module context.

2. Tag mode/reset/traffic state for the failure.

3. Validate assumptions against spec and assertions.

4. Compare outcome with whiteboard template, interview rubric, sample answers.

5. Choose one reversible action and define regression upfront.

Did the action work?

BEFORE / AFTER — CDC/RDC Whiteboard Framework

open critical issues
  ^
  |  o baseline
  |     o after fix batch
  |         o after protocol proof
  |             o signoff-ready
  +---------------------------------> closure iteration

Track issue burn-down with evidence quality, not only count.

CDC/RDC deep dive

Interview performance reflects production signoff thinking quality.

Concept diagram

INTERVIEW FLOW

classify -> explain mechanism -> propose fix -> state regression

Metric graph

PRACTICE SCORE

session1 62%
session2 78%
session3 89%

Reports and artifacts

• scenario completion

• answer rubric scores

• trap recovery quality

Mini case study

Candidate gave command-heavy answer but missed risk framing and waiver governance.

Debug branches

• Use mechanism-first structure

• name ownership and evidence

• close with signoff decision

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.