用于IToF传感器的极低功耗RISC-V专用处理器设计

IToF深度探测技术是当前主流的3D感知实现方案之一，该技术的核心部件是IToF传感芯片。随着当今社会数字化与智能化进程的加快，各科技领域对IToF传感芯片的需求日益提高，然而IToF传感芯片产能的提升引起了由芯片运行所带来的功耗问题。针对IToF传感器设计一款基于第五代精简指令集架构（RISC-V）的极低功耗专用处理器IToF-miniRV。IToF-miniRV包含支持RV32I指令集、RV32M指令集和自定义IToF型指令的处理器，以及用于加速深度计算和光幅度运算的IToF硬件加速器。将IToF-miniRV处理器与蜂鸟E203、PULPissimo这两款开源的基于RISC-V的超低功耗处理器分别部署在Xilinx Zynq-7000芯片上，进行FPGA资源使用情况和运行功耗的对比实验，结果表明，相比蜂鸟E203和PULPissimo，IToF-miniRV处理器的FPGA资源使用率分别减少5.2和10.9个百分点，运行功耗分别下降37.6%和89.7%。

Design of Ultra-Low-Power RISC-V Dedicated Processor for IToF Sensor

Indirect Time of Flight(IToF) depth detection technology is one of the current mainstream solutions to realize 3D perception.The core component of this technology is the IToF sensor chip.With the acceleration of digitization and intellectualization, the demand for IToF sensor chips is increasing in various scientific and technological fields.However, the increase in the production capacity of IToF sensor chips has created a power consumption problem caused by chip operation.To address this challenge, an ultra-low-power dedicated processor IToF-miniRV is designed based on Reduced Instruction Set Computer-Five(RISC-V) instruction set architecture.The IToF-miniRV includes a processor that supports the RV32I instruction set, the RV32M instruction set, custom IToF type instructions, and an IToF hardware accelerator for accelerating depth and optical amplitude calculations.The IToF-miniRV processor is deployed on an Xilinx Zynq-7000 chip with two open-source RISC-V-based ultra-low-power processors:Hummingbird E203 and PULPissimo.A comparison experiment on FPGA resource utilization and running power consumption shows that, compared with Hummingbird E203 and PULPissimo, the FPGA resource utilization rate of the IToF-miniRV processor decreased by 5.2 and 10.9 percentage points, respectively, and the running power consumption decreased by 37.6% and 89.7%, respectively.