initialize_floorplan produces an invalid or unexpected boundary. What do you check?
From PDVerse PnR Interview Handbook · pdVerse Mentor Guide
Short Answer
Check control type, shape, side lengths or ratios, boundary points, orientation, offsets, retained objects, site definition, and whether an old boundary was intentionally kept.
Technical Explanation
Several options can describe the outline; mixing assumptions can produce a surprising result. Compare requested geometry with report_design, row creation, grid snapping, and imported physical constraints. Verify units before recalculating.
Formula Or Decision Rule
Decision rule: boundary and core dimensions must match the documented calculation after legal snapping.
What To Check
• Warning sign: The command is rerun repeatedly with guessed offsets. • Inspect: choose one affected region, macro, row, pin, path, or net and trace the physical cause. • Correct: Return to one declared geometry method, clear conflicting assumptions, regenerate, and report.
Command Checks & Actions
• initialize_floorplan -control_type <core_or_die> -shape R -side_length {<side_a> <side_b>} -core_offset <offset>: creates the initial die, core, rows or site array, and tracks from declared controls
• report_design -floorplan: reports the floorplan state understood by the tool
Run only the commands needed for this question. Save the report with the floorplan version and analysis context.Healthy, Suspicious & Hard-stop Results
• Healthy: Check control type, shape, side lengths or ratios, boundary points, orientation, offsets, retained objects, site definition, and whether an old boundary was intentionally kept. • Suspicious: The command is rerun repeatedly with guessed offsets. • Hard stop: required legality or physical feasibility is missing or unexplained. Return to one declared geometry method, clear conflicting assumptions, regenerate, and report.
Common Mistake
Do not hide the symptom with an arbitrary utilisation, halo, channel, blockage, pin move, or die-size change. The command is rerun repeatedly with guessed offsets.
What The Interviewer Is Testing
The interviewer is testing whether you can connect “initialize_floorplan produces an invalid or unexpected boundary. What do you check?” 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 the command is rerun repeatedly with guessed offsets. I would use the named objects and reports to decide whether to iterate, waive, or return the issue.”
Practical Example
Symptom: The command is rerun repeatedly with guessed offsets. Corrective path: Return to one declared geometry method, clear conflicting assumptions, regenerate, and report.
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