On test data compression and n-detection test sets

We consider the relationship between test data compression and the ability to perform comprehensive testing of a circuit under an n-detection test set. The size of an n-detection test set grows approximately linearly with n. Therefore, one may expect a decompresser that can decompress a compressed n-detection test set to be larger than a decompresser required for a compact conventional test set. The results presented in this work demonstrate that it is possible to use a decompresser designed based on a compact one-detection test set in order to apply an n-detection test set. Thus, the design of the decompresser does not have to be changed as n is increased. We describe a procedure that generates an n-detection test set to achieve this result.