Conditional Fault Collapsing in Digital Circuits with Shared Structurally Synthesized BDDs

The paper presents a scalable method with linear complexity for structural fault collapsing in digital circuits using Shared Structurally Synthesized BDDs (S3BDDs) to reduce search space for test generation, speed up fault simulation and make fault diagnosis easier. The paper introduces a new term of conditional fault collapsing, and identifies the conditionally collapsed faults, produced as the result of transforming SSBDDs into S3BDDs. The necessary and sufficient conditions, to be satisfied by test patterns, are developed to guarantee that the collapsed faults are detected without special targeting them. Experiments demonstrate better results for structural fault collapsing compared to state-of-the-art.