Physical DFT Debug: Review Checklist

Review checklist

Review Checklist for Physical DFT Debug focuses on physical root-cause turnaround, repeat DFT route violations, signoff escape risk. The goal is to convert metric movement into mechanism, owner, and release decision.

• Run tags and scenario context are explicit.

• Constraints and legality assumptions are documented.

• Quality, timing, and test-power checks are included.

• Diagnosis evidence supports residual-risk decision.

• Owners signed: PD owner, STA owner, DFT owner.

Signoff ownership

OWNERSHIP MAP - Physical DFT Debug

artifact              owner
----------------      -----------------
architecture/report PD owner
constraints/setup   STA owner
physical/test       DFT owner

Name an owner for each failing metric cluster.

DFT deep dive

Physical integration quality decides whether DFT architecture survives implementation realities.

Concept diagram

PHYSICAL DFT FLOW

chain planning -> floorplan placement -> route -> test timing/power validation

Metric graph

ROUTING BURDEN

poor chain order -> longer routes -> more hold buffers

Reports and artifacts

• scan physical wirelength

• congestion heatmap

• test clock skew

• handoff issue tracker

Mini case study

Late scan reorder reduced route detours and eliminated a major shift hold cluster before signoff.

Debug branches

• Correlate chain order with congestion

• Place compression logic near chain clusters

• Keep DFT-PD handoff versioned

Senior review question

Ask: what evidence proves this DFT decision is safe for production?

Key takeaways

• State metric, lot/corner context, and pattern tag with every claim.

• Treat timing, power, and quality as one signoff problem.

Common pitfalls

• Chasing coverage without legality checks.

• Ignoring test-power side effects of pattern changes.

• Debugging silicon without reproducible tags.

Principal DFT review addendum

Physical DFT debug traces violations to chain ordering, buffering strategy, clock topology, or extraction/view mismatches.

Metric: physical root-cause turnaround, repeat DFT route violations, signoff escape risk