Easily testable network based on positive polarity OR-Coincidence expansion.
Chen Xie-xiong · Journal of Zhejiang University(Science Edition) · 2008
For improving testability of digital circuits, easily testable realizations of positive polarity OR-Coincidence network(PPOC network) for arbitrary logic functions were proposed and universal test sets which detect all single stuck-at faults in the network were given.The realizations were based on positive polarity OR-Coincidence expansion(PPOC) of logical functions and the Exclusive-NOR(EXNOR) part of the network emploied cascade or tree structure.For improving testability,only one control point and one observation point are needed for the realization with EXNOR-cascade and three control points and one observation point for the realization with EXNOR-tree were needed.For an n-variable function,the cardinal numbers of universal test sets for the two realizations were(n+4) and(n+5) respectively.It's very suitable to be generated by Built-in Self-Test for such short universal test sets and test time can be saved greatly.