JouleQuest: An Accurate Power Model for the StarCore DSP Platform

This paper describes the design, validation and integration of JouleQuest: a comprehensive power estimation framework for the StarCore DSP platform. The goal of this work is to provide a power model coupled to a fast platform simulator, that can accurately predict the power variability on the platform. The power consumption model for the DSP core is an instruction level model while the power models for the peripheral components are based on functional operations executed by the blocks. The DSP core instruction level power model is a generic model applicable to any VLIW DSP core and improves on existing VLIW models by reducing the model complexity to O(n) where n is the number of processor instructions. The peripheral power models are based on a novel technique of characterizing the power of operations and operation sequences executed on the peripheral block. This allows accurate power modeling for complex peripheral blocks like cache controllers, arbiters etc. having significant parallel operation execution. The platform power has been verified to give an average error of approximately 5% across a large suite of DSP and control benchmarks having high power variability. The paper concludes with a case study demonstrating the usage of the power simulator for energy optimization of ITU-T G.729 speech-codec software.