STA Mastery · All levels
SI Signoff Reports: Review Checklist
Review Checklist for SI Signoff Reports.
Review checklist
Review Checklist for SI Signoff Reports focuses on SI-clean path %, remaining aggressor violations, signoff waiver count. 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: SI lead, STA lead, signoff owner.
Sign-off ownership
OWNERSHIP MAP — SI Signoff Reports
artifact owner
---------------- -----------------
timing report SI lead
SDC/constraint STA lead
implementation signoff owner
Every WNS cluster needs a named owner before ECO.STA deep dive
Coupling makes delay a function of neighbors, not just wire RC.
Concept diagram
SI ON VICTIM
victim net delay = base_RC + coupling_from_aggressorsMetric graph
DELTA DELAY ON CRITICAL PATHS
no SI ████████ 1.2ns
with SI ██████████ 1.35ns (+150ps)Reports and artifacts
delta delay report
aggressor list
noise peaks
SI WNS delta
Mini case study
Setup fixed by upsize but SI worsened — spacing ECO on bus bits recovered margin.
Debug branches
Re-run SI after every timing ECO
Shield wide switching buses
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
SI signoff aggregates delta delay and noise against foundry rules and product margin; reports must map to fix ownership.
Metric: SI-clean path %, remaining aggressor violations, signoff waiver count