Scan Compression

Scan Compression is test-data reduction using on-chip decompression and compaction to cut tester bandwidth and test time - It is a core technique in advanced digital implementation and test flows.

What Is Scan Compression?

• Definition: test-data reduction using on-chip decompression and compaction to cut tester bandwidth and test time.
• Core Mechanism: Compressed stimuli expand internally into scan patterns while response compactors generate manageable signatures.
• Operational Scope: It is applied in design-and-verification workflows to improve robustness, signoff confidence, and long-term product quality outcomes.
• Failure Modes: Uncontrolled X propagation or excessive aliasing can hide defects and weaken diagnostics.

Why Scan Compression Matters

• Outcome Quality: Better methods improve decision reliability, efficiency, and measurable impact.
• Risk Management: Structured controls reduce instability, bias loops, and hidden failure modes.
• Operational Efficiency: Well-calibrated methods lower rework and accelerate learning cycles.
• Strategic Alignment: Clear metrics connect technical actions to business and sustainability goals.
• Scalable Deployment: Robust approaches transfer effectively across domains and operating conditions.

How It Is Used in Practice

• Method Selection: Choose approaches by failure risk, verification coverage, and implementation complexity.
• Calibration: Tune compression ratio with X-masking policy and verify retained coverage against baseline ATPG.
• Validation: Track corner pass rates, silicon correlation, and objective metrics through recurring controlled evaluations.

Scan Compression is a high-impact method for resilient design-and-verification execution - It is essential for cost-effective test of modern high-gate-count SoCs.