Synthesis of power-managed sequential components based on computational kernel extraction

This paper introduces a power optimization paradigm for sequential componen ts based on the concept of computational kernel, a highly simplified logic block whose behavior mimics the steady-state behavior of the original speci fication. We present a flexible framework that supports a number of algorit hmic options for carrying out kernel extraction. We first describe an exact symbolic procedure that is applicable to components for which only a funct ional specification (i.e., the state transition graph) is available. Due to its computational complexity, this procedure is mainly of theoretical inte rest and it is not usable for large circuits. We then propose two approxima te algorithms that can be adopted in practical situations. The first one is simulation-based and it is suitable to cases where input data streams repr esenting typical operation of the component are available. The second appro ach performs kernel extraction by iteratively refining a structural represe ntation of the component obtained through synthesis. The impact of the powe r optimization paradigm based on kernel extraction is demonstrated by the r esults of extensive experimentation carried out on a number of benchmarks o f different characteristics and nature.