Patent ID: 7539958

Claim:
A method for estimating the average-case activity in a digital circuit, the method comprising: assigning initial activity values to outputs of flops in the digital circuit; and repeatedly updating the activity values in an iterative procedure until a predetermined termination criterion is met, wherein the updating of the activity values uses: stochastically derived predetermined formulae for predesignated types of circuit elements when a search in the iterative procedure finds any one of the predesignated types of circuit elements, wherein: the predesignated types of circuit elements include at least one of a flop with a recirculation multiplexer coupled to an input of the flop, a clock gated flop or an enable flop, the predetermined formulae are used to calculate the activity values at an output of the predesignated types of circuit elements using the activity values at inputs of the predesignated types of circuit elements, and the predetermined formulae are based on a stationary distribution of a Markov chain that is associated with the predesignated types of circuit elements, and probability propagation techniques for combinational logic elements that are not predesignated types of circuit elements when the search finds any one of the combinational logic elements in the digital circuit.