Behavioral-level DFT via formal operator testability measures

摘要

The focus of this research is on the testability analysis of the operators in the behavioral description prior to synthesis. The controllabilities of the inputs to an operator and the observabilities of the outputs of the operation are computed from the value ranges of the variables that serve as the inputs and outputs. Candidate hard-to-test operations are selected for testability enhancement based on the computed testability measures for all the involved operations in the behavioral description. While value ranges have been applied to compute variable testability measures, this paper addresses computation of the operator testability. Experimental results show that circuits synthesized using our technique exhibit higher testability than variable selection while keeping the area-performance overhead to a minimum.