An Approach to Functional Level
Testability Analysis · 1989
Published methods of testability analysis have concentrated on circuits with gates and relatively small functional primitives. As a result, they are applicable only after the detailed logic design of the circuit is complete. The design of testable systems requires that testability issues be considered throughout the design process. This requires methods of testability analysis that are applicable at higher levels than the currently available methods. In this paper, we present an approach to testability analysis applicable to circuits containing functional modules described behaviorally. We consider two types of modules - combinational modules described by binary decision diagrams, and sequential modules defined by state tables. Controllability and observability measures for such modules are defined, and algorithms developed for computing them. The method has been applied to a few small modules and circuits, and appears to be feasible.