A fault analysis method for synchronous sequential circuits

A new fault analysis method for synchronous sequential circuits is presented. Using the iterative array method, extended forward propagation and backward implication are performed, based on the observed values at primary outputs, to deduce the actual values of each line to determine its fault status. Any stuck fault can be identified, even in a circuit without any initialization sequence. A fault which is covered is tested unconditionally; thus the results obtained would not be invalidated in the presence of tested or untestable lines. Examples are given to demonstrate the ability of the method.<>