A novel scheduling-based CAD methodology for exploring the design space of ASICs for low power

This paper describes a novel approach to scheduling with multiple supply voltages in the high-level synthesis of ASICs. In a significant shift from the existing scheduling algorithms for multiple voltages, the proposed approach considers, identifies, and exploits the maximal parallelism available in an initial schedule, and applies a modified stochastic evolution mechanism to iteratively improve, or re-schedule, the previously obtained best-schedule to reduce the maximal power consumption of function-units. Based on simulation and evaluation of the proposed approach (using standard benchmarks), it is observed that a power savings of up to 80% is possible when three supply voltage levels, 5 V, 3.3 V, and 2.4 V are considered. In addition to scheduling for low power, the proposed methodology can serve as a vital guiding tool to a designer for studying the efficacy of different design choices before a final design option is selected.