On the use of Feedback Systems to Dynamically Control the Supply Voltage of Low-Power Circuits

In this paper a complete environment to design, model, and simulate DVS based processor system is proposed. It is based on the use of a co-processor which continuously computes the real average speed of the microprocessor. The whole system is modeled as a feedback system and simulated using a mixed signal simulation environment. It is shown how energy saving can be achieved using software and hardware dynamic voltage regulation. Key parameters, such as the set point management, the application computational load profile and the DC/DC output voltage characteristics are considered and their influence on the energy reduction studied. Therefore the proposed architecture and validation environment enable the designer to optimize the overall energy consumption of the system by making relevant trade-offs between software and hardware energy reduction techniques and the overheads brought by the implementation.