A Combinatorial Approach to X-Tolerant Compaction Circuits

Yuichiro Fujiwara, Charles J. Colbourn
2010 IEEE Transactions on Information Theory  
Test response compaction for integrated circuits (ICs) with scan-based design-for-testability (DFT) support in the presence of unknown logic values (Xs) is investigated from a combinatorial viewpoint. The theoretical foundations of X-codes, employed in an X-tolerant compaction technique called X-compact, are examined. Through the formulation of a combinatorial model of X-compact, novel design techniques are developed for X-codes to detect a specified maximum number of errors in the presence of
more » ... specified maximum number of unknown logic values, while requiring only small fan-out. The special class of X-codes that results leads to an avoidance problem for configurations in combinatorial designs. General design methods and nonconstructive existence theorems to estimate the compaction ratio of an optimal X-compactor are also derived.
doi:10.1109/tit.2010.2048468 fatcat:jz2uxmv5azcfbpozryqcbjc2aa