ATS单片微机控制直接数字频率合成器DDS AD进行参数设置和软件编程.doc

摘 要 在一些电子设备中，往往需要频率、幅度都能由计算机自动调节的信号源。采用诸如MAX038信号发生器芯片外加电阻及切换开关等器件虽然也能调节频率和幅度，但这种调节是离散的，且电路复杂，使用不方便。而采用直接数字合成芯片AD7008构成的可控信号源，可生产正弦波、调频波、调幅波及方波等，并且其信号的频率和幅度可由微机来精确控制，调节非常方便。  本论文介绍用AT89S51单片微机控制直接数字频率合成器DDS AD7008进行参数设置和软件编程，实现可生产正弦波、调频波、调幅波及方波等，并且其信号的频率和幅度可由微处理器来精确控制，调节非常方便。本设计课题是利用所学的电路和编程语言知识，用５１系列的单片机控制DDS芯片(AD7008)来完成的，可实现调频，调相，调幅信号的输出。 论文重点介绍了DDS的理论知识，然后详细介绍了实现这种理论的硬件设备，根据硬件设备确定设计方案。然后是对设计方案的具体描述。在描述中，详细介绍了AD7008的功能特点。 关键字：直接数字合成(DDS)；AD7008；AT89S51单片微机。 Abstract In some electronic equipments, which are often needed signal-source whose frequency and scope all can be automatically controlled by computers. If we use signal generating device such as MAX038 chip component and so on sur- resistance and cut switch,it can controll the frequency and the scope. However, this kind of modulation is discrete,and its electric circuit is complex, so it is not convenient for ues. But if we use the controllable signal-source that constituted by the direct digital synthesis chip AD7008, it can produce the sine wave, the frequency-modulation wave, the amplitude-modulation wave and the square-wave and so on. its signal frequency and its scope may come from the accuracy control by the microcomputer. Its modulation is extremely convenient. The paper introduced the parameter establishment and the software programming which are controlled directly by AT89S51 monolithic microcomputer through the direct digital synthesis DDS chip AD7008. To realize the producible sine wave, the frequency-modulation wave, the amplitude-modulation wave and the square-wave and so on, and its signal frequency and scope may come the accuracy control by the microprocessor. The modulation is extremely convenient. This design topic using the electric circuit knowledge and the programming language knowledge to control the DDS chip (AD7008) with AT89S51 monolithic microcomputer to complete and realize the frequency modulation, phase modulation, and amplitude-modulation signal output. The paper in