Ignored exceptions appear in the report. What does that mean?
From PDVerse PnR Interview Handbook · pdVerse Mentor Guide
Short Answer
An exception may be overridden, redundant, malformed, or dominated by another constraint; its presence in SDC does not mean it affects analysis.
Technical Explanation
Treat this as a readiness check. It should produce named objects and a result that another engineer can repeat from the same handoff.
What To Check
• Warning sign: A carefully written multicycle or false path has no effect. • Inspect: Keep at least two possible causes open, then use one named object and the active mode or scenario to separate them. • Correct: Inspect ignored and dominant relationships, object resolution, and precedence; correct or remove stale intent with the STA owner.
Command Checks & Actions
• report_exceptions -ignored: shows timing exceptions and their scope
• report_exceptions -dominant: shows timing exceptions and their scope
Run the commands in order. Each line answers a separate part of the check.Healthy, Suspicious & Hard-stop Results
• Expected: An exception may be overridden, redundant, malformed, or dominated by another constraint; its presence in SDC does not mean it affects analysis. • Investigate: A carefully written multicycle or false path has no effect. • Stop before floorplanning when required logic or timing coverage is missing or unexplained. Inspect ignored and dominant relationships, object resolution, and precedence; correct or remove stale intent with the STA owner.
Common Mistake
Do not assume the check passed just because ICC2 continued: A carefully written multicycle or false path has no effect. Fix or narrowly justify the named objects, then rerun the same command.
What The Interviewer Is Testing
Be ready to explain why this matters before floorplanning: A carefully written multicycle or false path has no effect.
Follow-up Question & Model Response
Model response: “I would save the report, inspect one affected object in the correct block and scenario, and make or request this correction: Inspect ignored and dominant relationships, object resolution, and precedence; correct or remove stale intent with the STA owner. Then I would reopen the clean checkpoint and rerun the same evidence.”
Practical Example
Symptom: A carefully written multicycle or false path has no effect. Corrective path: Inspect ignored and dominant relationships, object resolution, and precedence; correct or remove stale intent with the STA owner.
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