Low Power Behavioral Synthesis

In this paper, a framework for reducing power during behavioral synthesis is proposed. A new parameter called Cycle Power Product (CPP) is defined which captures the power characteristics as an equally weighted sum of normalized mean cycle power. To minimize this parameter uses multiple supply voltages and dynamic frequency clocking and results in reduction of both energy and transient power. The cycle differential power can be modeled either as the mean deviation from the average power or as the cycle-to-cycle power gradient. The switching activity information is obtained from behavioral simulations. Based on the above we develop a new datapath scheduling algorithm which attempts at power and energy minimization by minimizing the CPP parameter during the scheduling process. The type and number of functional units available becomes the set of resource constraints for the scheduler. Experimental results indicate that the scheduler that minimizes CPP instead of conventional energy or average power as objective function could achieve significant reductions in power and energy.