Fast predictive control of micro controller´s energy-performance tradeoff

A two voltage level electronic device is interesting because the clock frequency and the supply voltage level could be reduced in order to decrease the energy consumption. However, these two quantities have to be controlled respecting certain rules, and decreasing them leads to a reduced computational speed. In this paper a control architecture is proposed to deal with this power performance tradeoff. First, a fast predictive control technique gives the best computational speed set point to minimize the penalizing high voltage running time. Then, the frequency and the supply voltage are controlled together in order that the measured speed tracks this set point. Finally, the proposal clearly gives an important reduction of the energy consumption. Moreover, the control strategy is robust to process variability and therefore suitable for 45 nm, 32 nm or smaller implementations.