A macro is inside the core but off-grid or illegally oriented. Is this a minor warning?
From PDVerse PnR Interview Handbook · pdVerse Mentor Guide
Short Answer
No. It can break manufacturing/block-grid requirements, pin access, array alignment, or power connectivity; treat it as a hard stop for that macro placement.
Technical Explanation
Inside the fence is not the same as standing on a legal coordinate. Check allowed orientation, alignment grid and point, origin, dimensions, pin sides, power pins, and repeated-instance consistency.
Formula Or Decision Rule
Decision rule: the final transformed macro satisfies every applicable legality and interface condition.
What To Check
• Warning sign: The macro is manually nudged until one warning disappears. • Inspect: choose one affected region, macro, row, pin, path, or net and trace the physical cause. • Correct: Apply the approved constraints, snap deliberately, and rerun macro and floorplan-rule checks.
Command Checks & Actions
• set_macro_constraints -allowed_orientations <orientation_list> -alignment_grid <grid_name> <macro_collection>: records allowed macro or I/O placement constraints
• check_design -checks {dp_pre_macro_placement}: runs named design-planning check groups
• check_floorplan_rules: reports configured floorplan-rule violations
Run only the commands needed for this question. Save the report with the floorplan version and analysis context.Healthy, Suspicious & Hard-stop Results
• Healthy: No. It can break manufacturing/block-grid requirements, pin access, array alignment, or power connectivity; treat it as a hard stop for that macro placement. • Suspicious: The macro is manually nudged until one warning disappears. • Hard stop: required legality or physical feasibility is missing or unexplained. Apply the approved constraints, snap deliberately, and rerun macro and floorplan-rule checks.
Common Mistake
Do not hide the symptom with an arbitrary utilisation, halo, channel, blockage, pin move, or die-size change. The macro is manually nudged until one warning disappears.
What The Interviewer Is Testing
The interviewer is testing whether you can connect “A macro is inside the core but off-grid or illegally oriented. Is this a minor warning?” 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 macro is manually nudged until one warning disappears. I would use the named objects and reports to decide whether to iterate, waive, or return the issue.”
Practical Example
Symptom: The macro is manually nudged until one warning disappears. Corrective path: Apply the approved constraints, snap deliberately, and rerun macro and floorplan-rule checks.
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