Evaluation of an Adaptive Dynamic Voltage Scaling Scheme for Hard Real-Time Applications

In this paper we briefly describe the implementation method for an Adaptive Dynamic Voltage Scaling algorithm which supports a finite number of clock frequencies we then evaluate its performance and finally profile its implementation complexity on a fixed point DSP. The proposed algorithm is an intra-task DVS scheme that calculates the voltage-frequency profile based on the past execution history of the task. Using the Adaptive Multi-Rate speech encoder as an example of a task we show that the overhead imposed by the extra complexity of the algorithm is less than 1% of the speech encoder and gives a power saving of over 15%. We finally conclude the complexity of calculating the voltage-frequency profile is not a limiting factor, if applied to a sufficiently complicated task.