Reducing the Storage Requirements of a Set of Functional Test Sequences by Using a Background Sequence

An existing storage scheme for a functional test sequence T uses a vector B, called a background vector, to store only the differences between the test vectors of T and B. After selecting B, modifying T based on B reduces the storage requirements of T. This paper describes a storage scheme for a set of test sequences T that uses a test sequence B, called a background sequence, to store only the differences between the sequences in T and B. The use of a background sequence allows more flexibility in matching B to T. By selecting B from the sequences in T, storage of B does not increase the storage requirements of T, and B itself contributes to the fault coverage. The paper describes a procedure for selecting a background sequence B from a set of sequences T, and for modifying T (including B) in order to reduce the storage requirements of T.