What command order preserves the meaning of failures?
From PDVerse PnR Interview Handbook · pdVerse Mentor Guide
Short Answer
Establish identity and libraries, link, check structure/unbound objects, validate and apply SDC, inspect clocks/scenarios/exceptions, then run timing-health checks.
Technical Explanation
Each check depends on earlier facts. If linking is broken, clock and exception reports built on that design cannot be treated as trustworthy evidence.
What To Check
• Warning sign: Running one combined check first obscures whether the root cause is linking, structure, or constraints. • Inspect: Compare one named object across the related reports; the same object should tell a consistent story. • Correct: Run separate reports into distinct files and stop at the first dependency failure.
Command Checks & Actions
• current_block: confirms the active design block
• report_ref_libs: shows the reference libraries used for linking
• check_design -checks {netlist unbound dp_pre_floorplan}: runs the selected design-readiness checks
• check_netlist: reports structural connectivity problems
• check_timing: finds missing or inconsistent timing setup
Run the commands in order. Each line answers a separate part of the check.Healthy, Suspicious & Hard-stop Results
• Expected: Establish identity and libraries, link, check structure/unbound objects, validate and apply SDC, inspect clocks/scenarios/exceptions, then run timing-health checks. • Investigate: Running one combined check first obscures whether the root cause is linking, structure, or constraints. • Stop before floorplanning when required logic or timing coverage is missing or unexplained. Run separate reports into distinct files and stop at the first dependency failure.
Common Mistake
Do not assume the check passed just because ICC2 continued: Running one combined check first obscures whether the root cause is linking, structure, or constraints. 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: Running one combined check first obscures whether the root cause is linking, structure, or constraints.
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 separate reports into distinct files and stop at the first dependency failure. Then I would reopen the clean checkpoint and rerun the same evidence.”
Practical Example
Symptom: Running one combined check first obscures whether the root cause is linking, structure, or constraints. Corrective path: Run separate reports into distinct files and stop at the first dependency failure.
Continue practising