RDC Structural Checks: Inputs & Outputs

Inputs and outputs contract

Inputs & Outputs for RDC Structural Checks focuses on unsafe reset crossing count, unresolved RDC warnings, waiver backlog. The goal is to convert issue observations into mechanism-backed closure decisions.

Treat CDC/RDC signoff as a contract across architecture, RTL, DV, and signoff governance. Most late surprises are contract mismatches, not tooling gaps.

INPUTS
  - crossing inventory with intent classification
  - reset tree and release dependency model
  - protocol assumptions and assertion package
  - CDC/RDC tool configuration + waiver policy

OUTPUTS
  - severity-tagged open issue list
  - protocol/reset proof evidence
  - owner-assigned closure plan
  - signoff or escalation memo

Crossing sequence

CROSSING FLOW — RDC Structural Checks

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

Key metric: unsafe reset crossing count, unresolved RDC warnings, waiver backlog

Ownership map

OWNERSHIP MAP — RDC Structural Checks

artifact                  owner
----------------------    -------------------------
design intent           RDC owner
verification evidence   RTL owner
signoff decision        methodology lead

Every open CDC/RDC issue needs one accountable owner before waiver or fix.

CDC/RDC deep dive

Reset release ordering is a first-order reliability contract.

Concept diagram

RESET RELEASE FLOW

assert global -> clocks stable -> sync release per domain -> first transaction

Metric graph

BOOT STABILITY

passes per 1k boots: 920 -> 980 -> 999

Reports and artifacts

• reset dependency matrix

• RDC warning classes

• boot stress logs

• waiver aging

Mini case study

Domain B released before producer A was valid, causing rare startup deadlock.

Debug branches

• Correlate reset and clock timelines

• verify async assert/sync release

• exercise skewed release tests

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

RDC tools detect reset-origin and release-domain mismatches; violations must be triaged by intent, not mechanically waived.

Metric: unsafe reset crossing count, unresolved RDC warnings, waiver backlog