New Design Of The Central Control System In Reflectance Difference Spectrometer Using Field Programmable Gate Array

Field Programmable Gate Array (FPGA) becomes favored by engineers andtechnicians, since it has been invented. The design approach based on hardwaredescription language (HDL) makes FPGA to have competitive advantages in thefields of high-speed, high-density digital logic circuit design. Promoted by the hugedemand of the market for system-level design tools, the embedded systemdevelopment mode (such as Altera company’s NiosII soft-core processor) based onsoft-core processor is accepted and popularized quickly after it is introduced. For themixed complex application requirements of controlling, communication and dataprocessing, the use of soft-core embedded FPGA and self-developed functional modebased on HDL, is an efficient, fast and flexible solution.In the thesis, the electronic control system for reflectance difference spectrometeris developed for the purpose of improving the performance of the instrument andstrengthening the ability of adapting to the environment, the main contents of thisthesis are as follows:1.The working principle of the reflectance difference spectrometer is introduced,some defects of the old control system are also analyzed, and a new design schemebased on FPGA is put forward.2.The synchronous serial communication between FPGA and angle encoderbased on Verilog hardware description language, and the real-time data acquisition ofangle is completed on the system. The detectors and the synchronization control ofangle encoder in the system are also designed.3.Based on NiosII soft-core processor and ISP1362type USB interface chip,. Thesoftware in USB master-slave mode is programmed in FPGA, achieving the USBcommunication of FPGA, computer and detector, and then the control of detector andthe data acquisition, storage, transmission for spectrum using FPGA is designed.4.Combined the HDL design mode and the embedded soft-core design mode, thesynchronization control system between detector and angle encoder and the real-timedata acquisition module is developed. A larger number of experimental results showthat the accuracy of acquired data, the synchronization performance and theacquisition speed meet the instrument needs well.