The primary objective of digital testing is to ensure that the manufactured hardware performs exactly as designed. A "high quality" test solution is defined by three critical metrics:
Without high-quality testing, a manufacturer risks shipping defective products, leading to costly recalls, damage to brand reputation, and safety hazards in critical applications like medical devices or avionics.
Boundary scan places a shift register between each chip pin and internal logic. It allows testing of interconnects on PCBs without physical probes.
Standard instruction set:
Consider an ADAS controller chip (16nm, 200M gates, 500MB memory). The requirement: Zero Defect ( < 1 DPPM). The primary objective of digital testing is to
The High-Quality DFT Solution implemented:
Result: The chip passed AEC-Q100 Grade 1 (-40°C to +125°C) qualification. The test cost per device dropped by 40% due to compression, while DPPM remained under 2 for 100 million shipped units.
ML models predict:
Solution: Use a D-algorithm (or PODEM, FAN) for combinational logic; extend to sequential via time-frame expansion. Result: The chip passed AEC-Q100 Grade 1 (-40°C
Example (D-algorithm for SA0):
Output: A test vector set achieving >99% stuck-at fault coverage.
Modern DFT integrates test compression to reduce data volume. A decompressor expands a small number of input channels into many internal scan chains, while a compactor reduces output pins.
Result: 10–100× reduction in test data volume and test time. FAN) for combinational logic
AI is revolutionizing test quality. Neural networks can now:
✅ Do's:
❌ Don'ts: