Sequential circuit testing: from DFT to SFT

Sequential circuit testing is an active research area due to its applicability, its practicality, and its complexity. This paper gives an overview of the sequential automatic test pattern generation approaches and the classical and more recent design-for-testability methods. However, recent trend is to move towards synthesis-for-testability (SFT) approach. In this paper, we describe some of the work done by others as well as our current research using SFT techniques. In particular, the ability to perform SFT on large sequential circuits is discussed.