Pseudorandom Test Pattern Generator, LFSR Layout

In order to verify the functionality of a circuit, one usually needs to apply all possible inputs to the circuit and check the corresponding outputs for functionality. Since most circuits are complex and have many inputs and outputs, such an exhaustive testing takes a prohibitively long amount of time. To address this problem, a pseudo-random test vector generator can be used for such a test, which cycles through an unrelated sequence of vectors in an attempt to achieve maximum fault coverage for the circuit under test.