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STA Mastery · All levels

Path Group War Room: Step-by-Step Walkthrough

Step-by-Step Walkthrough for Path Group War Room.

Step-by-step analysis walkthrough

Use when you own Path Group War Room in a timing war room.

  1. Open signoff scenario list — note worst WNS corner.

  2. report_timing -max/-min on failing group.

  3. Trace launch and capture clocks on critical path.

  4. Check exceptions and generated clocks on path.

  5. Break down cell vs net delay.

  6. Compare implementation vs signoff view if delta suspicious.

  7. Assign owner: RTL, synth, PD, CTS, SI.

  8. Propose ECO with hold/SI check plan.

  9. Run regression matrix.

  10. Update closure dashboard and memo.

Artifacts to collect

  • path group heatmap, owner assignment sheet, daily WNS standup notes

  • SDC file

  • SPEF tag

  • MMMC scenario list

  • ECO ticket

Decision memo template

diagram
STA DECISION MEMO — Path Group War Room
corner/mode:
WNS/TNS:
hypothesis:
ECO:
regression:
owners: timing closure lead, STA lead

Reference visuals

War room board

diagram
PATH GROUP | WNS  | OWNER    | ACTION
reg2reg    | -80  | PD       | upsize buf
in2reg     | -40  | STA+pkg  | IO delay review
reg2cg     | -25  | CTS      | skew check

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

War rooms assign failing path groups to owning teams (RTL, synth, PD, CTS) based on delay breakdown and path class.

Metric: WNS per path group, endpoint owner assignment rate

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