The Design And Realization Of A Signal Acquisition And Processing System Based On DSP

With the rapid development of computer and information technology, Digital signal processing technology has been more and more important in high-speed and real-time processing. It is widely used in graph and image processing, voice identification, intelligent checking, industry control and other fields. A lot of real-time data acquisition and processing systems choose DSP (Digital Signal Processor) as his core processor, which ask for dealing with the collecting image data fast. In this paper, we proposed a high-speed data collection system based on the digital signal processing. We solved a lot of technology problems and difficulties in the system design and implement. The implement way of all kinds of function units is also introduced and analyzed in this paper.The thesis analyzes the characteristics, the working principle and the means of the chip selections, and brings forward the detailed schemes about the complete design, hardware circuit, software program and performance testing. This thesis lays emphasis on the hardware circuitry and construction and the software design.The data acquisition and processing system completes acquisition and processing to the analog signals and control of the machine using the chip of TMS320F2812. As this chip has abundant of peripheral, we can have a simple circuit architecture, a low cost and a short development time by using it. We choose USB (Universal Serial Bus) as the communication interface of DSP and the computer which can fulfill up data transfer and the control to DSP. The acquisitioned and processed data is transferred to PC through the USB and dealed with by the top software.According to the system's need, we choose the analog to digital unit inside DSP as the system's through the compare of two design themes, which is proved to meet the need of the system totally through the results of tests. Some methods are also bringed forward to improve to the precision of the internal A/D converter and remove the electric disturb. Furthermore, we use simultaneous sampling mode and cascaded sequencer mode to improve the acquisition and convert speed.As for the order of electrifying for core professor-TMS320F2812, it's CPU is electrified earlier than the I/O peripherals which is different from others. Aiming at this problem, a power supply design method has been brought forward, which solves the order of electrifying. For the large amount of image data that requires to be processed, the inter memory resources of F2812 can't meet the demand. As for this point, this theme extends the outside memory according to the internal memory characters of the DSP chip.In addition, this theme gives the flow chart of the main program and the detail methods about the system's software design and implement, including system's initialization, data acquisition, analog to digital converter unit, data processing, data communication and code optimization. The development flow of USB firmware is also introduced in this theme. At the end, some questions and the means how to solved them are referred to in the system debugging.The system designed in this theme has the characters of small cubage, high-speed, low cost, flexible programming, simple interface and convenient, which can settle the problems of the system's cubage and the cost in practical applications. It's common to the image acquisition and processing system whose data quantity is less than 1M×8bit. And it have broad implication future.