基于嵌入式ARM的波形发生器的研究与实现

【作者】 刘国栋；

【导师】 任立勇； 李贤温；

【作者基本信息】 电子科技大学 ， 软件工程， 2008， 硕士

【摘要】 任意波形发生器(AWG, Arbitrary Waveform Generator)是随着不断进步的计算机技术和微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信号源。AWG能够产生各种标准波形信号和用户自定义任意波形信号,并且精度高、稳定性强、可重复性和易操作性好,具有广阔的应用前景。本文研究的是一种基于ARM (Advanced RISC Machines)嵌入式系统和直接数字合成技术(DDS, Direct Digital Synthesis)的新型任意波形发生器系统。其中,DDS是其核心技术原理。DDS技术是一种先进的频率合成技术,其主要优点是易于程控,相位连续,输出频率稳定度高、范围宽、分辨率高,是任意波形发生器研究的一个重要方向。本文详细讨论了DDS系统的基本组成、工作原理和特点。同时,对应用DDS技术合成信号的频谱杂散性作了详细分析,给出了改善合成信号频谱纯度的方法。DDS技术的实现依赖于高速、高性能的数字器件。本文选择基于S3C44B0X微处理器的ARM嵌入式系统实现DDS技术。S3C44B0X是三星公司的一款ARM7芯片,基于ARM公司的16/32位RISC处理器内核ARM7TDMI设计,拥有高速、低功耗、多功能、高性价比,特有双指令集等诸多优异的性能,适于作为仪器的主控制芯片。本文从工程应用的角度出发,深入研究基于ARM嵌入式系统、以DDS技术为核心的任意波形发生器技术。设计了一个以S3C44B0X+TMS320VC5416双核系统和AD9854 DDS专用芯片为主要功能单元的实际任意波形发生器,阐述了软/硬件详细开发过程,给出了任意波形发生器的电路框图、电路原理图、设计过程和详细的软件流程图,介绍了任意波形编辑软件的开发流程。通过测试,证明本任意波形发生器达到了预期的设计要求。最后,对全文的主要研究内容进行了总结,指出了设计过程中遇到的问题及存在的不足之处,给出了主要研究结论和今后的研究方向。更多还原

【Abstract】 With the development of the technique of computer and microelectronics, a new measure instrument--Arbitrary Waveform Generator (AWG) comes into being. AWG can generate many kinds of standard and arbitrary waveform signals. It has good future with its precision, stabilization, repeatability and facility.The intention of this thesis is to design a new-style AWG that based on ARM (Advanced RISC Machines) embedded system and Direct Digital Synthesis (DDS) technique. DDS is the key technique. DDS is an advanced technique on frequency synthesis. Its primary advantages are controlling facility, continuous phase and fine frequency resolution. It is an important field of the AWG design. This paper introduces in detail the composition, the working principle and the properties of DDS, analyses the reason of DDS phase noise, and gives the method of reducing the noise.Realization of DDS depends on the digital devices of high speed and high performance. In this thesis, the ARM embedded system based on S3C44B0X is selected to realize DDS. The Samsung ARM7 microprocessor chip S3C44B0X was developed using a 16/32-bit ARM7TDMI RISC processor core designed by Advanced RISC Machines, Ltd. Its high-speed, low-power, multifunctional, cost effective, simple and elegant design is particularly suitable for the central controller chip of instruments.This thesis attempts to use the advanced embedded system, deeply researches how to design the AWG based on ARM embedded system and DDS technique from the view of project application. The author has researched and developed an AWG with the technique of DDS. The circuit framework, designing method, detailed software flow chart and program of arbitrary waveform editor are given in this paper. The result of experimentation proves that this AWG has attained the desire of design.Finally, the main research contents of full thesis are summarized, main research conclusions and innovation points are given, and the insufficiency of this paper and research emphases in the future are pointed out.更多还原