A Design Of High Speed And Real-time DSO Based On FPGA

Although Digital Storage Oscilloscope (DSO) appeared from 80s of last century,but it didn't have certain characters of Analog Oscilloscope.For example,it's bandwidth was narrow, resolution was low and real-time performce was bad.However, after decades of years,as the development of digital circuit and large-scale intergrated circuits,especially the performance of high speed A/D Converter and the storage capacity of RAM grown rapidly,the sampling rate and real-time performance of DSO are greatly improved.More and more engineers used DSO instead of analog oscilloscope.This thesis introduce a design of DSO which has dual-channel,1GSPG sampling rate,8-Bit resolution and 200MHz bandwidth.According to these performance characters, a structure based on ARM+FPGA is presented. The author explained three modules of the design, which include hardware composed by high speed A/D Converter and FPGA, software composed by interpolation, FFT and digital filter, GPIB interface logic module design.This thesis put forwords design idea and method based on the traditional DSO. National Semiconductor company introduced a new series high performance,low power,Dual 8-Bit,500MSPS A/D Converter which had Dual-Edge Sampling mode in 2005.In DES mode,a single input is sampled by twice,resulting in 1GSPS with a 500MSPS input clock.As digital data buffer and memory,FPGA is selected from Xilinx company's Sparten-3E series by considering the price and high performance.FPGA can extract useful data from A/D Converter's muti-channel based on different time-base,it also finish some digital signal process task such as Sinc interpolation filter.The other digital signal process include FFT and digital filter are finished in ARM.GPIB interface is universal in DSO,in order to make good use of the FPGA's internal resource and reduce circuit scale, The GPIB function is integrated in the FPGA.At lase, we debug the A/D Converter Sampling system by Chipscope Pro.A analyse about why the bad data is appeared is given,and the author propse a solution about how to eliminate the glich.At last,the useful data is given.