基于SOPC的便携式数字示波器设计与实现

摘要

To facilitate the external measurements and maintenance tasks, we proposed an implementation of portable digital storage oscilloscope system, based on programmable chip (System on Programmable Chip) technology. Unlike the traditional design of FPGA for date access process and MCU for display control, the design of portable digital oscilloscope based on SOPC embeds Nios II into FPGA. The embedded system acts as a CPU which controls display of LCD waveform and parameters. In addition, FPGA logical resources are used to design access control module of sampling data and realize trigger access function of that. The practical test results indicate that for the portable digital oscilloscope, the measurement range of signal amplitude is 50 mV~20 V with measuring error less than 4%and the measurement range of frequency is 1 Hz~50 MHz with measuring error less than 2.5%.%为了方便外场测量及维护工作，提出了一种基于片上可编程系统（System On Programmable Chip）技术的便携式数字示波器实现方案。与传统FPGA作为数据存取处理MCU作为显示控制的设计方案不同，基于SOPC的便携式数字示波器设计方案通过在FPGA中嵌入Nios II系统，作为CPU实现对LCD波形及参数显示控制；利用FPGA的逻辑资源，设计采样数据的存取控制模块，实现采样信号的触发存取功能。实际测试结果表明，该便携式数字示波器信号幅度测量范围为50 mV~20 V，测量误差小于4%，频率测量范围为1 Hz~50 MHz，测量误差小于2.5%。