A Fine-Grain Variation-Aware Dynamic ${\rm Vdd}$ -Hopping AVFS Architecture on a 32 nm GALS MPSoC

In order to optimize global energy efficiency in the context of dynamic process, voltage and temperature variations in advanced nodes, a fine-grain adaptive voltage and frequency scaling architecture is proposed for multiprocessor systems-on-chip (MPSoC), where each processing element is an independent voltage-frequency island. This architecture has been implemented on a 32 nm globally asynchronous locally-synchronous MPSoC. It shows up to 18.2% energy gains thanks to local adaptability compared with a global dynamic voltage and frequency scaling approach using 25% timing margins between slow and nominal process, by reducing margins to 60 ps of the real process. These gains are obtained for a total area overhead of 10% including local frequency/voltage actuators, sensors, and digital controller.