RDC Structural Checks: Software / Programmer View

RTL / implementation view

Reset coding style affects RDC safety and X-propagation behavior.

What designers feel

• Intermittent sync failure

• mode-dependent startup hangs

RTL structure impact

• state machine handshake discipline

• reset release assumptions

• cross-domain data packaging

Synthesis interaction

• retiming can invalidate implicit assumptions

• lint clean does not imply CDC-safe

RTL-side mitigations

• explicit synchronizer wrappers

• protocol assertions

• reset sequence tests

RTL VIEW — RDC Structural Checks
// ensure crossing intent and protocol assumptions are explicit in module contract

Implementation layers touched

CDC/RDC OWNERSHIP LAYERS — RDC Structural Checks

layer                 owns                            common failure
------------------    -----------------------------   -----------------------------
design intent         crossing architecture           wrong topology selected
protocol semantics    req/ack, fifo, ordering        liveness/deadlock bugs
reset behavior        assert/deassert sequencing      boot instability
analysis setup        tool rules + waivers            false confidence
signoff governance    risk acceptance + dashboard     stale critical waivers

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