Early sample test technique

Classical test pattern generator (TPG) only concern about producing maximum length of test vector. It does not consider the previous (history) of test vectors which have been generated in producing next test vectors. As a result, succeeding test vector may capture the same fault which resulted in low accumulated fault coverage. In this paper we introduced a new approach for testing both combinational circuits and sequential circuits with the aim to highlight on the importance to consider previous test vectors which have been generated in trying to capture different faults as the generation proceeds to produce consequence test vector. The proposed test method also manages to produce high fault coverage even though the test was sampled early without the need to wait till the last clock. Several experiments have been carried out on ISCAS benchmarks circuit and the results were compared with different test methods. The proposed test method proved effective, producing high fault coverage with a limited number of test vectors.