A fast untestability proof for SAT-based ATPG

—Automatic Test Pattern Generation (ATPG) based on Boolean satisfiability (SAT) has been shown to be a beneficial complement to traditional ATPG techniques. Boolean solvers work on instances given in Conjunctive Normal Form (CNF). The required transformation of the ATPG problem into CNF is one main part of SAT-based ATPG and needs a significant portion of the overall run time. Solving the SAT instance is the other main part. Here, the time needed is often negligible – especially for untestable faults This paper presents a preprocessing technique that accelerates the classification of untestable faults. Those occur more frequently with increasing design sizes in industrial practice. In order to avoid overhead on testable faults, an untestability prediction is motivated. This increases the robustness of the entire ATPG process. The efficiency of the proposed method is shown during the experiments.

• Type: Conference
• Year: 2009
• Where: DDECS
• Authors: Daniel Tille, Rolf Drechsler
• Keywords: Conjunctive Normal Form, DDECS 2009, Faults This Paper, Hardware, Untestable Faults