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ECO Regression Matrix: Review Checklist

Review Checklist for ECO Regression Matrix.

Review checklist

Review Checklist for ECO Regression Matrix focuses on corners re-run, new violations introduced, signoff delta. 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 lead.

Sign-off ownership

diagram

OWNERSHIP MAP — ECO Regression Matrix

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

Every WNS cluster needs a named owner before ECO.

STA deep dive

ECO without regression is a coin flip.

Concept diagram

diagram

ECO LOOP

failing path -> fix -> setup check -> hold check -> SI -> MMMC matrix

Metric graph

diagram

ECO PROGRESS

WNS
 0 |              o target
-50|        o
-100|   o baseline
    +-----------------> ECO #

Reports and artifacts

pre/post WNS
hold delta
leakage delta
ECO ticket log

Mini case study

48-hour tapeout crunch: VT swap fixed setup; hold fixed with route on short path — order mattered.

Debug branches

Never ship setup-only proof
Logical ECO needs equivalence

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

Every ECO must re-run the agreed MMMC matrix plus SI; regression hygiene prevents shipping a fix that breaks another corner.

Metric: corners re-run, new violations introduced, signoff delta

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