Design Of Protocol Decoding And Waveform Feature Searching Algorithm In Digital Oscilloscope

With the rapid development of electronic information industry,testers’ demand for signal testing is growing rapidly.How to find interesting events in the mass of data and how to quickly obtain the information hidden in the complex protocol signals has become the essential function of many oscilloscopes.This paper takes the research of a digital oscilloscope project as the background,adopts the overall architecture of FPGA+IPC,uses C# language to develop softwarerelated functions on VisualStudio platform,and mainly realizes the protocol analysis,waveform feature search algorithm and software design of function modules.The specific contents are as follows:1.Protocol analysis module: on the premise of guaranteeing the smoothness of human-computer interaction,real-time access to user-set parameters and send hardware,control hardware triggering,decoding,RAM storage,synchronize hardware storage RAM and software data buffers and parse data packets,and display the result label in corresponding waveforms accurately under strict time constraints.This module adds the parsing function of MIL-STD-1553 B protocol signal on the basis of more than ten protocols that have been implemented.2.Research on waveform feature search algorithm: This paper explores eight common search types of waveform features,such as edge,pulse width/burr,window,slope,timeout,under-amplitude,logic,setup/hold time,and summarizes the search algorithm based on waveform features along sequence and pulse sequence.For the case of severe dithering waveform,a search algorithm based on basic point position along sequence and pulse sequence is proposed.3.Waveform feature search function module: realize the upper application of waveform feature search.The function of waveform scaling and translation can realize the expansion of horizontal and vertical directions.Save multiple groups of functions can set the search type and search conditions for many times and save the search results and parameters.The saved results will be marked with dark triangle.The details of parameters can be viewed through the event list.The automatic search function provides several search conditions of edge,pulse width / burr and under amplitude for training.The effect of search intensity can be controlled by adjusting the training proportion.This paper mainly uses the object-oriented design idea and multi-threaded design idea,completes the coding and function implementation of each module,and the test results of each module achieve the expected results.