Power analysis of a 32-bit embedded microcontroller

A new approach for power analysis of microprocessors has recently been proposed (Tiwari et al 1994). The idea is to look at the power consumption in a microprocessor from the point of view of the actual software executing on the processor. The basic component of this approach is a measurement based, instruction-level power analysis technique. The technique allows for the development of an instruction-level power model for the given processor, which can be used to evaluate software in terms of the power consumption, and for exploring the optimization of software for lower power. This paper describes the application of this technique for a comprehensive instruction-level power analysis of a commercial 32-bit RISC-based embedded microcontroller. The salient results of the analysis and the basic instruction-level power model are described. Interesting observations and insights based on the results are also presented. Such an instruction-level power analysis can provide cues as to what optimizations in the micro-architecture design of the processor would lead to the most effective power savings in actual software applications. Wherever the results indicate such optimizations, they have been discussed. Furthermore, ideas for low power software design, as suggested by the results, are described in this paper as well.