Advanced coupled voltage-frequency control for power efficient DVFS management

Power management is a hot-topic in complex System-on-Chip (SoC) designs. In the context of advanced technologies, Dynamic Voltage-Frequency Scaling (DVFS) techniques are widely proposed to improve efficiency. Nowadays, these mechanisms are composed of independent actuators controlling the applied voltage and clock frequency. A predefined sequence has to be used to switch from one state to another in order to avoid timing faults but increasing the energy cost. The timing of the sequence depends on the dynamic response of actuators. In this work, an external controller is designed in order to couple both actuators to manage the voltage and frequency transient periods, increasing power efficiency. The proposed controller has been implemented to couple a Vdd-hopping mechanism with a Frequency-Lock Loop circuit.