What does dp_pre_floorplan actually prove?
From PDVerse PnR Interview Handbook · pdVerse Mentor Guide
Short Answer
It checks technology-file information, layer directions, and the presence of horizontal and vertical layers; it is only one readiness component.
Technical Explanation
dp_pre_floorplan is a narrow technology readiness check. It checks technology-file information and routing-layer directions, including the presence of horizontal and vertical layers.
What To Check
• Warning sign: A passing dp_pre_floorplan result is misreported as proof that the netlist and SDC are correct. • Inspect: Compare one named object across the related reports; the same object should tell a consistent story. • Correct: Run structural, unbound, SDC, clock, scenario, exception, and timing-health checks separately.
Command Checks & Actions
• check_design -checks {dp_pre_floorplan}: runs the selected design-readiness checks
• get_design_checks: lists checks supported by the installed release
Run the commands in order. Each line answers a separate part of the check.Healthy, Suspicious & Hard-stop Results
• Expected: It checks technology-file information, layer directions, and the presence of horizontal and vertical layers; it is only one readiness component. • Investigate: A passing dp_pre_floorplan result is misreported as proof that the netlist and SDC are correct. • Stop before floorplanning when required logic or timing coverage is missing or unexplained. Run structural, unbound, SDC, clock, scenario, exception, and timing-health checks separately.
Common Mistake
Do not assume the check passed just because ICC2 continued: A passing dp_pre_floorplan result is misreported as proof that the netlist and SDC are correct. 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 passing dp_pre_floorplan result is misreported as proof that the netlist and SDC are correct.
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: Run structural, unbound, SDC, clock, scenario, exception, and timing-health checks separately. Then I would reopen the clean checkpoint and rerun the same evidence.”
Practical Example
Symptom: A passing dp_pre_floorplan result is misreported as proof that the netlist and SDC are correct. Corrective path: Run structural, unbound, SDC, clock, scenario, exception, and timing-health checks separately.
Continue practising