Analysis and generation of control and observation structures for analog circuits

Using control and observation structures (COSs) to enhance the testability of analog circuits has recently received much attention. However, previous methods for generating COSs are rather ad hoc. In this paper, we present an algorithm that can systematically generate all possible COSs based on the user's requirements. Extensive analysis on the common features, constraints, possible operations, and required number of switches and nodes for a COS has been carried out. Various kinds of matrices to represent the properties of COSs are defined. A compatibility checking method based on a transitive closure procedure is developed to identify, the required COSs. Experimental results show that the algorithm can effectively generate all required COSs, including many COSs that are previously not identified.