How do you make the final floorplan proceed, iterate, waive, or return decision?
From PDVerse PnR Interview Handbook · pdVerse Mentor Guide
Short Answer
Proceed only when boundaries, rows, macros, channels, pins, feedthroughs, tracks, PG reservation, voltage areas, congestion, and early timing are physically credible and reproducible. Iterate quality risks, waive only justified intent, and return upstream defects to their owner.
Technical Explanation
The gate converts many reports into one owned engineering decision. Classify each finding as hard stop, design-intent question, quality risk, expected warning, or documented waiver. Reopen the written floorplan and reproduce the evidence.
Formula Or Decision Rule
Decision rule: no unexplained hard stop; every open risk has evidence, owner, action, and review date.
What To Check
• Warning sign: A clean automated check is treated as approval. • Inspect: choose one affected region, macro, row, pin, path, or net and trace the physical cause. • Correct: Run the staged gate, inspect quality reports, record dispositions, reload the write-out, and sign the decision matrix.
Command Checks & Actions
• get_design_checks: lists checks supported by the installed release
• check_design -checks {dp_pre_macro_placement dp_pre_power_insertion dp_pre_pin_placement dp_floorplan_rules}: runs named design-planning check groups
• check_floorplan_rules: reports configured floorplan-rule violations
• check_pin_placement: checks pin-placement legality and access-related conditions
• check_feedthroughs: checks targeted feedthrough classes and constraints
• report_design -floorplan: reports the floorplan state understood by the tool
• write_floorplan -output <output_dir>: writes reproducible floorplan information to files
Run only the commands needed for this question. Save the report with the floorplan version and analysis context.Healthy, Suspicious & Hard-stop Results
• Healthy: Proceed only when boundaries, rows, macros, channels, pins, feedthroughs, tracks, PG reservation, voltage areas, congestion, and early timing are physically credible and reproducible. Iterate quality risks, waive only justified intent, and return upstream defects to their owner. • Suspicious: A clean automated check is treated as approval. • Hard stop: required legality or physical feasibility is missing or unexplained. Run the staged gate, inspect quality reports, record dispositions, reload the write-out, and sign the decision matrix.
Common Mistake
Do not hide the symptom with an arbitrary utilisation, halo, channel, blockage, pin move, or die-size change. A clean automated check is treated as approval.
What The Interviewer Is Testing
The interviewer is testing whether you can connect “How do you make the final floorplan proceed, iterate, waive, or return decision?” to measurable physical evidence and an owned correction.
Follow-up Question & Model Response
Follow-up probe: What would make you change your decision? Model response: “I would change it if the same controlled rerun shows that a clean automated check is treated as approval. I would use the named objects and reports to decide whether to iterate, waive, or return the issue.”
Practical Example
Symptom: A clean automated check is treated as approval. Corrective path: Run the staged gate, inspect quality reports, record dispositions, reload the write-out, and sign the decision matrix.
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