Minimizing Observation Points for Fault Location

We investigate the benefit of inserting observation points in a circuit in order to improve its diagnostic resolution. The insertion of the points is done so that each fault has a unique signature on these points under at least one of the applied test patterns. The observation points are scan-like elements that serve as test-phase outputs and can be organized in and observed through one or multiple chains. Experimental results show good tradeoffs between number of observation points that need to be inserted and diagnostic resolution achieved.