A method is presented for identifying primitive path-delay faults in non-scan sequential circuits and generating robust tests for all robustly testable primitive faults. It uses the concept of sensitizing cubes introduced in an earlier paper and a new, more efficient algorithm for generating them. Sensitizing cubes of the nextstate and output logic are used to obtain static sensitizing vectors that can be applied to the non-scan sequential circuit as part of a vector-pair. These vector-pairs are also used in deriving robust tests. Initializing sequences from a reset state and sequences that propagate fault effects from flip-flops to primary outputs are also generated. The proposed method has been implemented and used to derive tests for primitive faults in ISCAS'89 and MCNC'91 benchmark circuits.
Ramesh C. Tekumalla, Premachandran R. Menon