A HYBRID METHODOLOGY FOR SWITCHING ACTIVITIES ESTIMATION

In this paper, we propose a hybrid approach for estimating the switchi ng activities of the internal nodes in logic circuits. The new approac h combines the advantages of the simulation-based techniques and the p robability-based techniques. We use the user-specified control sequenc e for simulation, and treat the weakly correlated data inputs using th e probabilistic model, The new approach, on one hand, is more accurate than the probabilistic approaches because the strong temporal and spa tial correlations among control inputs are well taken into considerati on. On the other hand, the new approach is much more efficient than th e simulation-based approaches because the weakly correlated data input s are not explicitly simulated. We also discuss the situation where BD D's are built in terms of internal nodes so that large circuits can be handled. Extensive experimental results are presented to show the eff ectiveness and efficiency of our algorithms.