Functional scan chain testing

TitleFunctional scan chain testing
Publication TypeConference Paper
Year of Publication1998
AuthorsChang, D, Lee, T-C, Cheng, K-T, Marek-Sadowska, M
Conference NameDesign, Automation and Test in Europe, 1998., Proceedings
Date Publishedfeb
KeywordsATPG, automatic testing, fault detection, flip-flops, functional logic, functional scan chain testing, functional scan paths, logic testing, sequential circuits, sequential fault simulation, test point insertion
AbstractFunctional scan chains are scan chains that have scan paths through a circuit's functional logic and flip-flops. Establishing functional scan paths by test point insertion (TPI) has been shown to be an effective technique to reduce the scan overhead. However, once the scan chain is allowed to go through functional logic, the traditional alternating test sequence is no longer enough to ensure the correctness of the scan chain. We identify the faults that affect the functional scan chain, and show a methodology to find tests for these faults. Our results have the number of undetected faults at only 0.006% of the total number of faults, or 0.022% of the faults affecting the scan chain