The impact of testing on VLSI design methods

The question `why design for testability'? is answered by discussing some existing test philosophies. Exhaustive testing, functional testing, and structural testing are treated, also with regard to their usefulness for VLSI circuits. There is no general agreement on how to design for testability. Various approaches exist, and each has its specific applications. Some of these approaches are discussed in detail, also regarding the influence of the complexity on necessary CAD tools for test pattern generation.