基于低功耗SoC的微型图像采集系统设计

Design of Miniature Image Acquisition System Based on Low Power System on Chip

针对低成本和低功耗的物联网SoC芯片发展要求,基于SMIC 55 nm CMOS工艺,以低功耗开源处理器RI5CY的SoC芯片为平台,结合片内含有DSP与A/D转换功能的低电压CMOS图像传感器OV7725,设计并实现了一款基于开源RISC_V指令集架构SoC芯片的图像采集控制系统.文中介绍了图像采集控制系统的结构,并详细阐述基于AHB总线的图像采集控制器的设计.控制器采用一种改进的异步FIFO来实现不同时钟域的同步设计,具有小面积和低功耗的特点.通过Modelsim仿真、DC综合以及FPGA验证,结果表明:该系统实现了视频图像数据的采集和传输,操作流程简单,易于软件调试,支持应用最高带宽可达37 MB/s. SoC芯片系统的时钟主频为200 MHz,芯片总面积为3 250×3 648μm2,总功耗仅为24.419 mW.

Based on the development requirements of low-cost and low-power Internet SoC chip, an image acquisition and control system is designed and implemented based on open source RISC_V instruction set architecture SoC chip and SMIC 55nm CMOS process, which uses the low-power open source processor RI5CY SoC chip as a platform and combined with the Low-Voltage CMOS Image Sensor OV7725 with the integrated DSP and A/D conversion chip inside. This paper introduces the block diagram of the image acquisition and control system, and describes a design of image acquisition controller based on AHB bus in detail. An improved asynchronous FIFO with low power and small area is used to realize the synchronous design of different clock domains. According to the results of Modelsim simulation, DC synthesis and FPGA verification shows that the system realizes the video image data acquisition and transmission,which operation flow is simple and easy to debug, and the maximum of the data transmission bandwidth come up to 37MB/s. The chip total area is 3250 μm x 3648 μm and power consumption is only 24.419 mW.