Bellevue: A 50MHz variable-width SIMD 32bit microcontroller at 0.37V for processing-intensive wireless sensor nodes

In the context of wireless sensor nodes for the Internet-of-Things, there is a need for low-power high-performance computing cores for video monitoring applications. In this paper we present a custom 50MHz 32-bit microcontroller running at 0.37V built on a 65nm LP/GP CMOS process. Part of an energy-harvesting SoC with on-chip CMOS imager, it features adaptive voltage scaling, low-power 1.55μW sleep mode, and a variable-width SIMD pipeline and multiply/divide unit, achieving 7.7μW/MHz overall.