STA Mastery · All levels

Library Set & Opcond Mapping: Review Checklist

Review Checklist for Library Set & Opcond Mapping.

Review checklist

Review Checklist for Library Set & Opcond Mapping focuses on library mismatch count, opcond alignment errors, derate mapping gaps. 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: library owner, STA owner, CAD owner.

Sign-off ownership

diagram

OWNERSHIP MAP — Library Set & Opcond Mapping

artifact              owner
----------------      -----------------
timing report       library owner
SDC/constraint      STA owner
implementation      CAD owner

Every WNS cluster needs a named owner before ECO.

STA deep dive

Signoff WNS is the minimum across the full scenario matrix.

Concept diagram

diagram

MMMC

corners (ss/tt/ff) x modes (func/test) x views (signoff RC)
= scenario set -> min(WNS) is signoff

Metric graph

diagram

WNS HEATMAP BY CORNER

        ss    tt    ff
setup  -80   +10   +5
hold   -15   -2    -8

Reports and artifacts

per-corner WNS
mode summary
lib map audit
view delta

Mini case study

Passed TT typical but failed SS hold — signoff matrix was incomplete; added low-voltage mode.

Debug branches

Isolate failing scenario first
Never compare unlike SPEF tags

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

Each corner binds liberty libraries and operating conditions; wrong mapping makes every slack number meaningless.

Metric: library mismatch count, opcond alignment errors, derate mapping gaps

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