Showing papers by "Sanjeevikumar Padmanaban published in 2003"

Exact path delay fault coverage with fundamental ZBDD operations

Abstract: We formulate the path delay fault (PDF) coverage problem as a combinatorial problem that amounts to storing and manipulating sets using a special type of binary decision diagrams, called zero-suppressed binary decision diagrams (ZBDD). The ZBDD is a canonical data structure inherently having the property of representing combinational sets very compactly. A simple modification of the proposed basic scheme allows us to increase significantly the storage capability of the data structure with minimal loss in the fault coverage accuracy. Experimental results on the ISCAS85 benchmarks show considerable improvement over all existing techniques for exact PDF grading. The proposed methodology is simple, it consists of a polynomial number of increasingly efficient ZBDD-based operations, and can handle very large test sets that grade very large number of faults.

An implicit path-delay fault diagnosis methodology

Abstract: The first nonenumerative framework for diagnosing path delay faults (PDFs) using zero suppressed binary decision diagrams is introduced. We show that fault-free PDFs with certain validated nonrobust test may be used together with fault-free robustly tested faults to eliminate faults from the set of suspected faults. All operations are implemented by an implicit diagnosis tool based on the zero-suppressed binary decision diagram. The proposed method is space and time nonenumerative as opposed to existing methods which are space and time enumerative. Experimental results on the ISCAS'85 benchmarks show that the proposed technique is on average three times more efficient than the existing techniques.