Dynamic voltage scaling based on supply current tracking using fuzzy Logic controller

It has been demonstrated that dynamic voltage and frequency scaling (DVFS) leads to a considerable saving in dynamic and static power of a processor. In this paper, we present an adaptive framework that can be used to dynamically adjust supply voltage and frequency of a processor under different application workloads. Voltage scaling decisions are made by a fuzzy logic (FL) block based on variations of the processor's workload. By observing the supply-current of the processor and also its variation rate, the FL block can drive the processor to operate at the lowest possible voltage and also the corresponding minimum frequency, in which a specific application can meet all of its deadlines under time-constrained operation. As the voltage can change at the same time as the workload varies, significant savings in both dynamic and static power are achieved. Simulation results show that our approach outperforms a PID controller under distinct working loads.