Review checklist

Review Checklist for Compression Architectures focuses on compression ratio, decompressor channel utilization, aliasing 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: DFT architect, ATPG owner, test engineering owner.

Signoff ownership

OWNERSHIP MAP - Compression Architectures

artifact              owner
----------------      -----------------
architecture/report DFT architect
constraints/setup   ATPG owner
physical/test       test engineering owner

Name an owner for each failing metric cluster.

DFT deep dive

Compression saves tester time only when diagnosis observability remains credible.

Concept diagram

COMPRESSION LOOP

EDT/decompressor -> compressed patterns -> compactor responses -> diagnosis

Metric graph

PATTERN vs COVERAGE

coverage up   -> pattern count up
compression up -> pattern count down (until aliasing risk)

Reports and artifacts

• compression ratio dashboard

• pattern count trend

• X-source report

• diagnosis bucket summary

Mini case study

Compactor overflow plus unknown inflation caused false diagnosis; masking policy and channel map corrected.

Debug branches

• Separate X issues from silicon defects

• Replay failing patterns uncompressed

• Track tester memory budget

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

Compression inserts on-chip decompressors/compactors to reduce external tester pattern volume while preserving defect detection quality.

Metric: compression ratio, decompressor channel utilization, aliasing risk