Two-pattern generation based on accumulators with 1´s complement adders

Built-in self test (BIST) techniques are widely used in today´s complex integrated circuits, since they employ on-chip test pattern generation and response verification. Arithmetic BIST techniques utilize modules that commonly exist in datapath modules (accumulators, counters etc.). In order to perform the test generation and response verification operations. In order to detect sequential faults that occur into current CMOS circuits, two-pattern tests are required. Furthermore, delay testing, commonly used to assure correct temporal circuit operation at clock speed, requires two-pattern tests. In this paper a novel algorithm for the generation of two-pattern tests is presented. The presented algorithm utilizes modules included in datapath circuitry to generate two-pattern tests; its implementation in hardware compares favorably with techniques that have been presented in the open literature