【作者】 邱大强；

【导师】 胡兵；

【作者基本信息】 西华大学 ， 电力电子与电力传动， 2008， 硕士

【摘要】 任意波形发生器是随着计算机技术和电子技术在测量仪器中的应用而形成和发展起来的一类新型号的信号源,是现代测试领域内广泛应用的通用仪器之一。本文针对现有波形发生器普遍存在波形存储容量小、速度慢、操作不灵活等问题,设计了一款基于PCI总线的任意波形发生器。在设计时,本文根据DDS原理,提出使用专用DDS芯片和外扩高速动态存储器(SDRAM)的方法来构建系统,实现了对大容量长周期的任意波形的产生和对采集的波形回放的功能。由于PCI总线是一个地址和数据复用的高速总线,本文使用PLX公司的PCI专用接口芯片完成PC机对板卡的控制,同时采用可编程芯片完成动态存储器、系统时序逻辑及I/O口的控制。最后,完成了高速D/A转换、程控滤波、输出驱动等电路的设计和虚拟仪器界面的程序编写。本文的主要工作包括以下几个方面:1分析了DDS的原理和结构,提出使用专用DDS芯片和外扩波形存储器来构建系统的方案,从而实现高频率分辨率和高稳定度的任意波形发生器设计。2对系统模拟部分进行详细设计,通过使用PCI总线实现了PC机对板卡的控制。在分析了输出信号的频谱特性后,提出采用多频段的程控滤波方法,用户可自己选择合适的滤波器来确保输出波形的纯度。3对大容量存储器进行了研究,通过使用可编程芯片设计了SDRAM的控制器,实现了长周期的任意波形存储,同时也解决了板卡上主要信号的逻辑译码问题,提高了板卡的集成度和系统可靠性。4介绍了控制软件的设计,通过使用虚拟仪器技术完成友好的人机操作界面的程序设计,实现了生成标准波形和任意波形的功能,同时介绍了使用Windriver软件快速编写底层控制软件的方法。5根据设计要求制定了测试方案,针对调试和测试中出现的问题,提出了一些实际的解决措施。最后的测试结果基本达到了设计要求,并给出了主要的测试结果。更多还原

【Abstract】 With the application of the electronic and computer technology in measurement instrument, a new signal generator—Arbitrary Waveform Generator (AWG) emerges as the times require. It is wildly used in the modern testing field. In the paper, a new type of AWG is presented for the ubiquity problems which has a small memory resources for waveform data, low-speed or complex to handle.In the design, a scheme that used special DDS chip and high speed SDRAM to construct AWG system based on DDS theory was proposed. It made the AWG has the function that could generate large storage and long periodic waveform or reproduce waveform which had been sampled. Because the PCI Bus is a high speed bus that data and address transmitted in the same bus, we use a special PCI chip to fulfill the control that PC computer to card. In the same time, through the programmable chip (FPGA) to fulfill the function of SDRAM controller, system timing logic control and I/O control. At last it finished the design of high speed D/A conversion, filter, output drive circuit and software design of interface. The main contents of this paper are following:1 After analyzed the theory and structure of DDS, a scheme that use special DDS chip and SDRAM to build system is proposed. Through this scheme we can get an AWG which has a high-resolution and high stability.2 Finished analog circuit design of system, realized control that PC computer to card by PCI bus. Meanwhile, a scheme of multi-filter has been proposed after the analyzed the of output waveform. The user can choose suitable filter to ensure the pure of output waveform.3 Finished the research of large storage and utilizing FPGA to design the SDRAM controller. Fulfilled long period waveform storaged and resolve system’s main logic decode problems, meanwhile, improved the integration and reliability of system.4 Introduced software design and got a friendly operation interface by virtual instrument. The paper introduced the way of utilizing Windriver to build DLL file.5 Make out a test scheme accoding to design demand and proposed some effective solutions to the problems which are encountered in system debug. At last the main test result which indicated the design achieves the demand.更多还原