RDC Methodology

What this topic teaches

RDC Methodology focuses on closing CDC/RDC risk with mechanism-level reasoning. RDC methodology treats reset behavior as a first-class asynchronous interface requiring intent capture, structural checks, and targeted dynamic proof. Senior signoff depends on proving behavior with targeted evidence, not just clearing tool warnings.

The senior-engineer question

When reset-domain hazard coverage, unresolved RDC severity count, closure quality regresses, can you classify the hazard, identify accountable owners, and choose the smallest fix or waiver backed by evidence?

CDC/RDC SIGNOFF FLOW — RDC Methodology

crossing inventory + reset map
          |
          v
crossing classification (level/pulse/bus/reset)
          |
          v
structure + protocol + reset checks
          |
          v
critical issues + waiver review
          |
          v
fix / validate / regress / signoff

Picture the crossing behavior

Draw the behavior before touching tools. These visuals are the expected whiteboard baseline for reviews and interviews.

RDC methodology loop

intent capture -> structural run -> dynamic proof
        -> waiver board -> milestone gate -> archive

Crossing sequence

CROSSING FLOW — RDC Methodology

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

Key metric: reset-domain hazard coverage, unresolved RDC severity count, closure quality

Ownership layers

CDC/RDC OWNERSHIP LAYERS — RDC Methodology

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

Evidence to collect

• Primary metric: reset-domain hazard coverage, unresolved RDC severity count, closure quality.

• Primary artifact: RDC methodology guide, rule-set config, hazard taxonomy.

• Owners to involve: RDC lead, methodology owner, verification lead.

• At least one reproducer tied to mode/reset/traffic context.

• Decision record: fix, waive, or escalate with rationale.

Ownership map

OWNERSHIP MAP — RDC Methodology

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

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

Subpages in this topic

Each topic includes mechanism, I/O contract, metrics, debug, worked example, pitfalls, interview drills, checklist, theory, design tradeoffs, expanded case study, walkthrough, comparison matrix, software view, and silicon impact.

Key takeaways

• Classify crossing/reset hazards before proposing fixes.

• Pair structural results with protocol/reset behavioral proof.

• Treat waivers as bounded risk contracts, not cleanup shortcuts.

Common pitfalls

• Mass-waiving warnings near tapeout.

• Assuming local IP cleanliness guarantees SoC behavior.

• Skipping reconvergence and reset stress after CDC fixes.

CDC/RDC deep dive

RDC closure must connect IP assumptions to SoC reality.

Concept diagram

RDC CLOSURE

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

Metric graph

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.