Energy Consumption Estimation of Software Components based on Program Flowcharts

This paper presents and evaluates a new approach of energy estimation for single software components based on program flowcharts. This estimation is designed to be applicable early in the design process, which enables system designer to evaluate different design variants with respect to the energy consumption of the later system. The energy estimation model is based on individual flowchart elements and execution probabilities for branches and iterations. The used flowchart elements are for arithmetical calculations, flow control and reads/writes, which are a selection of possible elements used to show the feasibility of the approach. The estimation model is verified in a first step by using three commercially available benchmarks. The flowcharts of these are utilized to estimate the energy consumption by using the presented model. The comparison between estimated and measured energy consumption of an exemplary embedded system results in an estimation error bandwidth between -11.9 % and +6.9 %. The main benefit of the presented approach is the applicability within the development phase "System Design" [1], i.e. previous to any software implementation. This is realized by using only available information of that development phase and generic elements to estimate the energy consumption.