CDC / RDC · All levels

Chip-level RDC Closure: Comparison Matrix

Comparison Matrix for Chip-level RDC Closure.

Comparison matrix

Structural checks and dynamic stress provide different confidence layers.

diagram
+------------------+----------------+----------------+----------------+
| Approach         | Strength       | Weakness       | Best when      |
+------------------+----------------+----------------+----------------+
| Conservative     | safe           | extra latency  | high-risk crossings |
| Balanced         | practical      | more setup     | most production paths |
| Aggressive       | fast schedule  | escape risk    | late-stage crunch |
| Refactor         | structural gain | long cycle     | recurring failures |
+------------------+----------------+----------------+----------------+

When to choose each approach

  • Select approach by silicon risk, not only schedule urgency

Interview traps

  • Global waiver spray

  • Unproven protocol assumptions

Evidence comparison

diagram
CDC/RDC EVIDENCE MATRIX — Chip-level RDC Closure

+-----------------------+----------------------------+----------------------------+---------------------------+
| Evidence              | Tells you                  | Does not prove             | Next action               |
+-----------------------+----------------------------+----------------------------+---------------------------+
| structural report     | crossing topology class    | protocol liveness          | add assertions/formal     |
| reset map             | release dependencies       | dynamic startup behavior   | run reset stress tests    |
| formal proof          | bounded safety/liveness    | real firmware sequence     | correlate with simulation |
| simulation stress     | observed mode behavior     | full state-space closure   | target unhit corners      |
| waiver log            | accepted residual risk     | technical correctness      | periodic revalidation     |
+-----------------------+----------------------------+----------------------------+---------------------------+

CDC/RDC deep dive

RDC closure must connect IP assumptions to SoC reality.

Concept diagram

diagram
RDC CLOSURE

IP reset intent + SoC sequencing -> structural checks -> dynamic stress -> signoff

Metric graph

diagram
MILESTONE READINESS

M-2 55%
M-1 82%
M0  100%

Reports and artifacts

  • top-level RDC opens

  • reset simulation coverage

  • chip integration blockers

  • waiver backlog

Mini case study

Each IP was locally clean, but top-level sequencing violation created cross-subsystem boot intermittency.

Debug branches

  • Audit subsystem assumptions

  • stress chip-level reset scenarios

  • close ownership gaps

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

Chip-level RDC closure depends on clean reset intent handoff from IPs and alignment between subsystem sequencing assumptions.

Metric: top-level RDC open count, subsystem handoff completeness, integration churn