# Rtl P5s Cdc Verify

> P5 CDC analysis: finds missing synchronizers and metastability risks, emits SDC constraints. Use for multi-clock designs or pre-synthesis CDC signoff.

- Skill: `babyworm/rtl-p5s-cdc-verify` (Agent Skill, multi-file: 4 files)
- Install (CLI): `npx skillmds@latest add babyworm/rtl-p5s-cdc-verify`
- Raw SKILL.md: https://api.skillmd.com/api/skills/babyworm/rtl-p5s-cdc-verify/raw
- Safety review: pending
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Coding & Dev Tools
- Author: babyworm (https://skillmd.com/u/babyworm)
- Updated: 2026-09-17
- Page: https://skillmd.com/skills/babyworm/rtl-p5s-cdc-verify

---


<Purpose>
Perform static CDC analysis on RTL to identify missing synchronizers, metastability risks,
and CDC constraint gaps. Outputs: lint/cdc/cdc_report.md + syn/constraints/cdc_constraints.sdc.

See `references/cdc-patterns.md` for synchronizer types, common violations, and SDC constraint templates.
</Purpose>

<Use_When>
- RTL design has multiple clock domains
- Pre-synthesis CDC sign-off required
- New clock domain or crossing signal added to existing design
- CDCcheck in pre-tapeout checklist
</Use_When>

<Do_Not_Use_When>
- Design is single-clock (CDC analysis not applicable)
- Only functional simulation needed
- Synthesis timing analysis needed (use rtl-synth-check instead)
</Do_Not_Use_When>

<Why_This_Exists>
CDC bugs are among the hardest to find in simulation because metastability is
non-deterministic. Static analysis catches structural CDC violations reliably
before they become intermittent silicon failures.
</Why_This_Exists>

## Prerequisites

RTL modules required with multiple clock domains:
- `rtl/**/*.sv` files must exist with `{domain}_clk` signals

If prerequisite is missing: WARNING — recommend running `/rtl-agent-team:rtl-p4-implement`.
Proceed with available artifacts — orchestrator will adapt scope.

## Execution

Task(subagent_type="rtl-agent-team:p5s-cdc-orchestrator",
     prompt="Execute CDC verification. User input: $ARGUMENTS")

Do not perform any work directly.
The orchestrator agent manages clock domain identification, cross-domain analysis,
SDC constraint generation, and optional commercial CDC tool integration.

## Output

- `reviews/phase-5-verify/{module}-cdc-report.md` — CDC analysis with VIOLATION/CAUTION/PASS verdict
- `syn/constraints/cdc_constraints.sdc` — generated SDC constraints for identified crossings