System Integration of RISC-V Processors with FD-SOI

Improving the energy efficiency of processor systems-on-chip (SoCs) is key to improving their performance and utility. The FD-SOI silicon process enables integrated systems that can deliver dramatic improvements in energy efficiency through system integration. This chapter presents the Raven-3 and Raven-4 testchips, fully integrated and fully featured SoCs which achieve energy-efficient operation with low overhead. RISC-V processors allow for innovation and experimentation in the context of a free, open architecture. Integrated switched-capacitor voltage regulators can achieve high conversion efficiency when coupled with adaptive clock generators. Custom SRAM macros operate at low supply voltages, enabling wide voltage scaling. An integrated body-bias generator allows run-time tuning of threshold voltage for improved performance or reduced leakage. Taken together, these innovations showcase the possibilities of FD-SOI technology.