Boundary-scan design principles for efficient LSSD ASIC testing

A boundary-scan logic design method that depends only on level-sensitive scan design (LSSD) principles has been developed for IBM CMOS application-specific integrated circuit (ASIC) products. This technique permits comprehensive testing of LSSD ASICs with high signal input/output (I/O) pin counts, using relatively inexpensive reduced-pin-count automatic test equipment (ATE). This paper describes the LSSD logic structures required, the reduced-pin-count testing and burn-in processes used, and the ASIC product design decisions that must be made to establish a consistent boundary-scan implementation.