| The oscillograph is a kind of most electronic measurements instrument that can directly and availably display measured signal in common use, the convenience observe and tests to measured various parameter of signal, complete to measure the purpose that the other instrument could not reach, is a beneficial tool of electron the engineer completing electrocircuit design and debug.Along with the electron technical progress, the step - down, function of the creation cost of digital oscilloscope are perfect, performance exaltation, become the basic testing tool of electricity laboratory gradually.Self-make the DSO(Digital Storage Oscilloscope) of one set in keeping with usage is also valid means of toughen, exaltation experiment personnel technique horizontal.This paper introduced development and present condition of DSO and elaborated work principle of DSO real-time samlping, equivalence samlping, analyzed basis theories of the DSO which adoptted the cost cheap double embedded controllers, the FPGA of the Cyclone2 series and the MCU of the AT89 series, were the controlling parts, applied the high-speed AD device which is cooperated with the high-speed DA device to make up of a programed control sampling circuit, combined with LCM of the OCMJ series to display, assistted the design and implementation of the USB interface which is controlled with CH375. Passed researching the work theories of DSO, analysis the test and the experiment conclusion of the related contents, put forward a set of low cost and more practical design project, then adopted FPGA, MCU double embedded controller, combined the control of USB interface controller with the programed control attenuation circuit, assistance module of LCM displaying and etc, completed the core contents development of self-made DSO.The DSO of this paper researched and designed was high-speed DA device AD5424 and high-speed Operational Amplifier AD8009 composing high speed of programed control attenuation circuit, implement the attenuation without distortion to the analog signal which peak to peak value is no higher than 10V; The signal that the attenuation got delivers to high-speed AD device AD9054 to carry on sampling; The digital data that the sampling got collects to FIFO that generated by FPGA for slowly saving; After the sampled data which slowly saves attains certain depth, FPGA sends the digitize waveform that save temporary in the FIFO to the MCU; Digitize waveform data send to LCM to display after MCU further analysis and handle, then completed the basic function of DSO.The paper mainly completed following task:1. Through analysising and researching for DSO, Created model of DSO In the hardware and software aspects. Created the model composed of the programed control data sampling circuit, MCU mainly control and PC, and created control software model according to the hardware model.2. Put forward the design and development project of self-made DSO. According to theories knowledge and technique means have had, put forward core technique and solution means of design and development of programed control attenuation technique, embedded PLL and FIFO technique, double embedded controllers communication of DSO, etc.3. Completed analysising in theories and investigate in practice for the programed control attenuation circuit under FPGA controlling, the programed control clock generating circuit, embedded FIFO circuit, embedded controller communication interface, LCM display under MCU controlling, etc. Carried out the data sampling and saving with programed control, and double directs communication in the double embedded system, and waveform displaying function, etc.4. It is Completed that is programed control data sampling circuit, design of MCU mainly control circuit layout, sealling, debugging etc. Create a basic embryo of self-make DSO.5. It is Completed that is writing each of main parts software code and debugging of DSO.Study the design and technique of carrying out of the DSO in paper, put forward newer theories and means for develop a DSO, provide precious experience for the similar system designning and developping. Through the research toward the programed control data sampling circuit, put forward a embedded programed control clock generator, a programmed control waveform generator, a programed control attenuation controller, a programed control waveform collection circuit further, provide valid means for design and studying system of controlling the frequency conversion, the waveform occurrence, waveform collection; Through the research of LCM displaying, solved the problem of adopting dot type LCM to display, provide new means for the system displaying; Through the research toward the USB interface, discuss possibility of self-made U type interface, provide one project to choose for data exchanging with PC in future; Through studying mode, method and means of multilayer circuit for each part circuit design, develop and sealing, lay the foundation of theories and practice for research and development that the future is engaged in this aspect.Because the limit in ability and time of author, just roughly completed research and investigate core technical of the DSO, basically completed the key technical in the whole system to link up and debug, there is gap to perfect whole system, have many worthy contentses for discussing and research further. In process of research future, the suggested begins to do to consider further from a few following aspects: Firstly, limited by research aim of this paper, attenuation circuit with program control was just designed and made. In future, high speed amplifier with program control will be design and research in order to make up limitation of measure range.Secondly, there is great blank to research in display interface development of LCM. As the most important aspect for a favorable testing apparatus, display should be paid more attention to. To add information of display, perfect interface of display, and enhance quality of display in the research process in future.Thirdly, touching screen will be applied. Nowadays, technique of touching screen has already been ripeness. In the process of researching for the paper, it had been considered, and had prepared the hardware for this function in advance. In future, it can be one aspect to think it over.Finally, double embedded controller system will be applied. Double embedded system was used to research and devise DSO in this paper, just for thinking about one much newer technique exploring. In future, single FPGA controller with higher ability or DSP controller can be considered to carry out in the research in order for the researcher to reduce the complexity of design and improve efficiency of instrument.A much more efficient self made DSO will be published by further analyzing, researching and perfecting.
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