Abstract
Many test schemes use signature analyzers to compact the responses of a circuit under
test. Unfortunately, there can be some faulty circuits with erroneous test responses but
exactly the same signature as in the fault-free case. Hence, methods are required to determine
how many faults become undetectable due to aliasing. Whereas previous work
concentrated on combinational circuits, this paper investigates signature analysis for
a wide range of sequential circuits, where the errors in successive responses are correlated.
It is shown that for almost all faults of these circuits the probability of aliasing
in a signature analyzer with k bits asymptotically approaches