Low-power multiplexer decomposition by suppressing propagation of signal transitions

Most circuits contain a number of multiplexers. An n-to-1 multiplexer is generally implemented by decomposition into 2-to-1 multiplexer. Due to its ordered tree structure, the n-to-1 multiplexer decomposition problem can be relatively easily solved for minimizing design considerations such as timing, area, and power consumption. In this paper, we propose an efficient and accurate method for estimating the number of signal transitions in multiplexer tree and a low-power multiplexer decomposition method using the proposed estimation method without any change of boolean functions of selection signals. The decomposition method is a kind of re-engineering method. Experimental results show that our proposed method can accurately estimate the number of internal signal transitions and their propagations, and our optimization technique using the proposed method reduces power consumption by considerable amount in multiplexer trees.