QUENTIN: A Near-Threshold Soc for Energy-Efficient IoT End-Nodes in 22Nm FDX Technology

Davide Rossi1,3, Pasquale Davide Schiavone2, Antonio Pullini2, Francesco Conti2,3, Frank K. Gurkaynak2 and Luca Benini2,3
1 Università di Bologna, IT
2 Integrated System laboratory, ETH, Zurich, Switzerland
3 Energy Efficient Embedded Systems Laboratory, University Of Bologna, Bologna, Italy


An increasing number of end-node IoT applications require high performance and extreme energy efficiency to deal with the high computational requirements of near-sensor data analytics algorithms, within a power envelope of few milliWatts for long battery lifetime. A significant improvement of energy efficiency for digital computing systems can be achieved exploiting near-threshold operation. We present Quentin: a near-threshold SoC based on the open-source PULPissimo architecture, implemented in 22nm FDX technology. The proposed SoC is built around a 32-bit RISC-V core “RISCY” optimized for energy efficient digital signal processing, 512 kByte of L2 memory, and an autonomous I/O subsystem featuring an IO DMA coupled with a standard set of peripherals. RISCY features a 32-bit, 4-stages in-order pipeline implementing the RV32IMFC RISC-V ISA plus domain-specific extensions for near-sensor data analytics such as packed-SIMD (additions, comparisons, logic, shuffle and dot product), bit manipulation, hardware loops, etc. This talk will present the implementation of the SoC in 22nm FDX, featuring an area of 2 mm2, a maximum operating frequency of 170 MHz (SSG, 0.59V, -40 C) and an estimated power consumption of 5 mW.