基于fpga的dds函数信号发生器.doc

DDS便携式信号源设计 摘 要 函数信号发生器在教学、通信、测量等领域是非常重要的工具，制作高性能信号发生器的关键在于频率合成技术。目前，常用的频率合成技术有直接频率合成、锁相频率合成和直接数字频率合成（DDS）等。其中全数字化的DDS技术是一种新的频率合成方法，由于其具有频率分辨率高、频率切换速度快、相位噪声低和频率稳定度高等优点，DDS技术成为现代频率合成技术中的佼佼者。 现场可编程门阵列（FPGA）设计灵活、速度快，在数字专用集成电路的设计中得到了广泛应用。在本设计中利用FPGA实现了一个DDS系统，该DDS系统的硬件结构是以FPGA为核心实现的，使用的是Xilinx公司的Spartan6系列FPGA。 为建立友好的人机交互界面，实现DDS信号信息的实时显示（包括信号类型和信号频率、幅度参数），在本设计中采用了CPU与FPGA构成联合系统的方案。其中，CPU选用的是Cortex-M4系列ARM单片机。 本设计最终实现了基于FPGA的DDS便携式信号源的设计，并且实现了对DDS信号源的控制及参数的实时显示，实现了预期设定的目标。 关键字：DDS信号源；FPGA；ARM Cortex-M4 Portable Signal Source Design Based on DDS ABSTRACT Function?generator?is?a?very?indispensable?tool?in?communications,?measu-rement,?teaching?and?other?fields, and the key to make a high performance signal generator is the technology of frequency synthesis. At present, the technology of frequency synthesis consists of direct synthesis, phase-locked synthesis and Direct Digital frequency Synthesis (DDS), etc. The fully digital DDS technology has such advantages as high frequency resolution, fast frequency switching speed, low phase noise and high stability, and it outshines other frequency synthesis methods. Field Programmable Gate Array (FPGA), because of its flexible designing and high speed, has been used more widely in digital ASIC. This design mainly discusses how to realize a DDS system with FPGA. The hardware of the design is Spartan6 series FPGA made by Xilinx Inc. In order to build a friendly man-machine interface to make sure the information such as the type, frequency and amplitude of the signal display in the screen at the real time, we choose the design based on both CPU and FPGA. The hardware of the CPU is ARM Cortex-M4 series single chip microcomputer. This design realizes the portable signal source based on DDS in the FPGA board, and it realizes the real-time display and the control of the parameters of the signal source. Finally, it achieves the desired objectives. Keywords：DDS signal source；FPGA；ARM Cortex-M4 目 录 1 绪论 - 1 - 1.1引言 - 1 - 1.2国内外现状及发展史 - 2