The VLSI circuit test problem-a tutorial

Defect-free integrated circuits (IC) cannot be guaranteed by VLSI circuit manufacturers. Circuit complexity, IC defect anomalies, and economic considerations prevent complete validation of VLSI circuits. These VLSI test problems are especially acute in high-reliability designs and will only worsen as IC circuit size increases. Designers of IC, board, and system projects must be aware of the difficult engineering challenges that are involved in verifying high-quality ICs. The authors discuss these topics and emphasize the need for basic design for testability methods that must be used to alleviate these problems.<>