Coupled voltage and frequency control for DVFS management

During the last decade, Dynamic Voltage-Frequency Scaling (DVFS) techniques have been widely proposed to improve integrated circuit efficiency. When these mechanisms are composed of independent actuators for supply voltage and clock frequency, a predefined sequence has to be used to switch from one state to another one in order to avoid undesirable conditions. On the contrary, when they are based on coupled drivers, the actuators need to be jointly designed. In the present work, a control mechanism is proposed to jointly control the voltage and frequency transient periods where both actuators are developed independently. At the same time that it ensures the global system stability and promotes design reuse, the proposed controller also increases the system performance during the transition. Implemented in STMicroelectronics 32nm bulk and 28nm FD-SOI technologies, it requires a relatively small silicon area and power consumption. Experimental results with two independently developed drivers are provided.