摘要:由于模拟示波器CRT的余晖时间很短，很难显示频率很低的信号且具有快速上升、下降时间的低重复速率信号就很难显示，而数字示波器的扫描轨迹亮度和扫描速度与信号重复速率无关，故可以很好地反映出来。利用FPGA的速度和计算优势，进而分析显示出信号各种参数。
本设计运用单片机和FPGA进行双CPU控制，配合交直流切换模块、继电器模块、缓冲器模块、可控集成运算放大器模块、增益可控模块、波形线基准电平控制电路、AD采样芯片和TFT彩色液晶，完成信号波形数据处理及显示的功能。
双CPU指的是按键扫描用ATMega8单片机来扫描，AD以及其他TFT显示等用FPGA来编程实现；增加了按键软开机和PWM控制屏幕渐亮渐灭功能，实用性得到增强；FIFO存储电路、显示控制电路、时钟产生电路、测频与控制电路这几部分电路设计在FPGA内部，使得程序设计比较方便。利用FPGA速度优势和计算优势，同时利用单片机价格优势设计，提高波形显示和处理精度，而且运用高对比度显示器件提高便携式时代野外性能。
此设计成果可以显示任意波形（频率带宽在20MHz、可实现正弦波频率3~5MHz、方波500KHz）。还实现了示波器的频率计算、幅值计算、FFT变换及双通道信号输入。
关键字：示波器；单片机；FPGA
ABSTRACT:Due to the very short afterglow time analog oscilloscope CRT, It's hard to show a low frequency signal and with fast rise and fall times of the low repeat rate signal is less likely to show, However scanning scan digital oscilloscope trace brightness and fast repeat rate has nothing to do with signal, it can be reflected very well. Using FPGA speed and calculation of advantage, further analysis showed the signal parameters.
This double CPU and FPGA design using single-chip microcomputer control, combined with, relay modules, AC-DC switching module buffer modules, control module, integrated operational amplifier gain control module, wavy line datum level, AD sample chips of control circuit and TFT color LCD, complete signal waveform data processing and display functions.
Double CPU means of is press scan with ATMega8 single tablets machine to scan, AD and other TFT displayed, with FPGA to programming implementation; increased has press soft power and PWM control screen gradually light gradually fight function, practical are enhanced; FIFO storage circuit, and displayed control circuit, and clock produced circuit, and measuring frequency and control circuit this several part circuit design in FPGA internal, makes programming comparison easy. Using FPGA speed and computing advantages and price advantage using single-chip design, improving the waveform display and handling precision and using high-contrast display devices to improve portable field performance of the times.
This design any waveform can be displayed (20MHz, frequency bandwidth can achieve 3~5MHz sine wave frequency, wave 500KHz). Also implements the oscilloscope frequency amplitude calculation, calculation, and dual channel FFT transform a signal input.
Keywords: Oscilloscope；Single-chip computer；FPGA
