Complete Search in Test Generation for Industrial Circuits with Improved Bus-conflict Detection

Test Pattern Generation (TPG) for sequential and/or 3-state circuits involves two important aspects which often are handled incorrectly: Bus conflict detection and completeness of search in TPG. The correct handling of both aspects strongly depends on the signal model used by TPG. We propose a novel, set-based, signal model using the power-set (i.e., the set of all possible subsets) of the basic values f0 ; 1 ; Zg. TPG using this signal model guarantees complete search, provides exact bus-conflict detection, and is more efficient than TPG using the traditional signal models for 3-state and sequential circuits. Experimental results demonstrate this by higher fault efficiencies combined with a large reduction of backtracking and computing time for sequential ISCAS'89 and industrial circuits. 1. Introduction Research on stuck-at fault TPG for Boolean and 3-state circuits, with or without scannable FlipFlops (FFs) has been carried out for many years now [4-15]. Still, fault efficiencies ..