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Signoff Regression Hygiene: Review Checklist

Review Checklist for Signoff Regression Hygiene.

Review checklist

Review Checklist for Signoff Regression Hygiene focuses on run-to-run WNS drift, database tag consistency, closure memo completeness. The goal is to connect the observable symptom to timing mechanism, ownership, and regression risk.

  • SDC revision and implemented clock/exception policy are named.

  • Clock/reset and CDC assumptions are reviewed.

  • Path groups, IO delays, and exception rationale are documented.

  • MMMC scenario list maps back to signoff requirements.

  • WNS/TNS artifact stored with corner/mode/view tags.

  • Owners signed: STA lead, CAD owner, program management.

Sign-off ownership

diagram
OWNERSHIP MAP — Signoff Regression Hygiene

artifact              owner
----------------      -----------------
timing report       STA lead
SDC/constraint      CAD owner
implementation      program management

Every WNS cluster needs a named owner before ECO.

STA deep dive

Debug hygiene separates senior STA leads from report readers.

Concept diagram

diagram
DEBUG ORDER

1. same tags?  2. constraints?  3. view?  4. real path?  5. ECO

Metric graph

diagram
ROOT CAUSE MIX (typical)

constraint bugs  ████████  35%
view mismatch    ██████    25%
real path        ██████    25%
methodology      ████      15%

Reports and artifacts

  • run manifest

  • SDC diff

  • SPEF tag

  • scenario isolation

Mini case study

Mystery regression: SPEF corner tag typo in run script — not a design bug.

Debug branches

  • Manifest every run

  • War room by path group

Senior review question

Ask: what corner/mode/view proves this topic is closed or failing?

Key takeaways

  • State corner, mode, view, and database tag with every slack claim.

  • Run setup and hold plus MMMC regression after every ECO.

Common pitfalls

  • Comparing STA runs with different SPEF or SDC tags.

  • Broad false_path to green-wash violations.

  • Setup-only ECO without hold check.

Principal STA review addendum

Signoff quality depends on reproducible runs: same lib, SPEF, SDC, scenarios, and tool versions — tagged and archived.

Metric: run-to-run WNS drift, database tag consistency, closure memo completeness

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