Arithmetic spectrum applied to fault detection for combinational networks

A method for the derivation of fault signatures for the detection of faults in single-output combinational networks is described. The approach uses the arithmetic spectrum instead of the Rademacher-Walsh spectrum. It is a form of data compression that serves to reduce the volume of the response data at test time. The price which is paid for the reduction in the storage requirements is that some of the knowledge of exact fault location is lost. The derived signatures are short and easily tested using very simple test equipment. The test circuitry could be included on the chip since the overhead involved is comparatively small. The test procedure requires a high-speed counter cycling at maximum speed through selected subsets of all input combinations. Hence, the network under test is exercised at speed, and a number of dynamic errors that are not testable by means of conventional test-set approaches will be detected