sta

Diagnose STA setup/hold violations by mapping report_timing fields to the slack equation.

1|1|Updated Jan 29, 2026
One-click install
npx skills add https://github.com/KishoreDamam/VLSI-agkit --skill sta
Or copy as Structured Prompt for Agent
Please help me install this Agent Skill.
Skill: sta
Source: https://github.com/KishoreDamam/VLSI-agkit/tree/main/.agent/skills/sta
Command: npx skills add https://github.com/KishoreDamam/VLSI-agkit --skill sta

SYSTEM DOCUMENTATION & REQUIREMENTS

💡 This Skill includes references (resource) components.

What problem does it solve?

This Skill helps you interpret static timing analysis results and determine why WNS/WHS fail, so you can close setup/hold violations correctly instead of blindly changing RTL.

Core Features & Use Cases

  • Timing-report triage and field-to-equation mapping: explains how launch/capture arrival, skew, uncertainty, derating, CRPR credit, and SI/crosstalk delta-delay terms affect slack.
  • Violation closure playbook: provides a practical decision process for classifying path types, sanity-checking constraint integrity, selecting the least disruptive fix tier, and validating with before/after report diffs.
  • Sign-off realism: guides correct MMMC view selection (setup at slow-slow, hold at fast-fast), and choosing the right derating model (OCV vs AOCV vs POCV), including how to avoid common STA misinterpretations.

Quick Start

Ask an AI coding agent to analyze your failing STA output by walking through report_timing (full_clock_expanded), extracting the key terms (skew, uncertainty, CRPR, derate, and SI deltas), classifying the path group, and recommending the cheapest constraint-then-logic fix with a validation checklist.

Frequently Asked Questions about sta

High-intent search queries and answers about installing and using this skill.

FAQPage Schema
How do I close static timing analysis setup and hold violations without changing RTL?

Static timing analysis setup and hold violations are closed by translating report_timing fields into the slack equation, classifying path groups, and selecting the least disruptive constraint or logic fix before validating with report diffs.

What do CRPR, OCV, and SI delta-delay mean in a timing report?

CRPR removes redundant clock path pessimism, OCV applies launch and capture derating, and SI delta-delay accounts for crosstalk impacts on arrival times within the slack equation during static timing analysis.

How do I interpret report_timing across MMMC corners for setup and hold?

Interpreting report_timing across MMMC corners requires selecting slow-slow views for setup analysis and fast-fast views for hold analysis, while extracting skew, uncertainty, and derating terms to verify report-to-equation consistency.

When should I use OCV versus AOCV or POCV derating models?

Choose OCV for flat path derating, AOCV for depth-based derating, and POCV for statistical variation modeling, selecting based on sign-off realism requirements and static timing analysis flow support.

Why does my timing closure fix fail validation after modifying constraints?

Timing closure fixes fail validation when ad-hoc changes bypass systematic path classification, meaning the report_timing slack equation terms like uncertainty, derate, or CRPR credit were not checked for consistency before applying the fix.

Does latch time borrowing affect setup violation analysis in static timing?

Latch time borrowing affects setup violation analysis by allowing arrival times to exceed the clock period, requiring specific latch semantics in static timing analysis to correctly classify and close the violation.