Abstract
Power estimation at the Register Transfer Level (RTL) often suffers from inadequate accuracy when applied to large designs, under realistic functional patterns. This problem is mainly due to the large variations of the switching activities induced in a circuit from one functional mode to another. We address this issue by a multi-mode methodology with two major enhancement techniques. Firstly, we use a power mode classification scheme to refine the power-consuming behaviors of a large design. Secondly, we incorporate a simulation-based linear approximation scheme for more efficient power characterization. The combination of these two techniques jointly contributes to higher accuracy. The proposed methodology has been realized as a practical tool that can fit into the commercial design flow. Experimental results of a number of real designs show that the estimation error can be reduced down to only 3.98 % on the average under realistic functional patterns.