Hardware/Software co-design with the HMS framework

Hardware/Software co-design is an increasingly common design style for integrated circuits. It allows the majority of a system to designed quickly with standardized parts, while special purpose hardware is used for the time critical portions of the system. The framework considered in this paper performs Hardware/Multi-Software (HMS) co-design for iterative loops, given an input specification that includes the system to be built, the number of available processors, the total chip area, and the required response time. Originally, all operations are done in software. The system then substitutes hardware (adder, multiplier, bus) for software based on the needability of each type of hardware unit. After a new hardware unit is introduced the system is rescheduled using a variation of rotation scheduling in which operations may be moved between processors. Experimental results are shown that illustrate the efficiency of the algorithms as well as the savings achieved.