Parallel sequence fault simulation for synchronous sequential circuits

A novel parallel sequence fault simulation (PSF) algorithm for synchronous sequential circuits is presented. The algorithm successfully extend the parallel pattern method for combinational circuits to sequential circuits by proposing a multiple-pass mechanism to overcome the state dependency in sequential circuits. The fault simulation is performed in parallel by partitioning the entire sequence into subsequences of equal length. Furthermore, techniques are developed to minimize the number of simulation passes. Notably, two compact counters, C-x and C-d, are proposed to faciliate the early stabilization detection of faulty circuit simulation with minimum space overhead. The experimental results on the benchmark circuits show that the speedup ratio over a serial sequence fault simulator based on ROOFS is 9.16 on average for pseudo random vectors. The parallel sequence algorithm of PSF is especially adaptable to parallel and distributed simulation which exploits sequence partition.