Maximizing the weighted switching activity in combinational CMOS circuits under the variable delay model

A methodology to find the couple of vectors maximizing the weighted switching activity in combinational CMOS circuits under variable delay model is presented. The weighted switching activity maximization problem is shown to be equivalent to a fault testing problem on a transformed circuit. A maximum weighted switching activity is achieved by test vectors covering a selected set of faults of the transformed circuit. Automatic Test and Pattern Generation tools are used to find the maximizing pair of vectors. The validity of the proposal is demonstrated on the ISCAS-85 benchmark circuits and the results show that the simulation time is reduced by an order of magnitude and the estimation of the maximum weighted switching activity is improved in comparison with pseudo-random sample simulation.