基于FPGA的DDS设计及实现

针对DDS频率转换时间短，分辨率高等优点，提出了基于FPGA芯片设计DDS系统的方案。该方案利用Altera公司的QuartusⅡ开发软件，完成DDS核心部分即相位累加器和ROM查找表的设计，可得到相位连续、频率可变的信号，并通过单片机配置FPGA的E^2 PROM完成对DDS硬件的下栽，最后完成每个模块与系统的时序仿真。经过电路设计和模块仿真，验证了设计的正确性。由于FPGA的可编程性，使得修改和优化DDS的功能非常快捷。

Design and Implementation of DDS Based on FPGA

A design scheme of DDS system based on FPGA is introduced for the merits of fast frequency conversion time and high resolution of DDS. The design of the phase accumulator and ROM lookup table which are the cores of DDS is achieved with the Quartus Ⅱ development software produced by Altera Company. The phase continuous and frequency variable signal can be obtained with design scheme. The download of DDS hardware is implemented by E^2 PROM based on MCU allocation FPGA, the time sequence simulation of each module and system is completed. After designing and testing circuit,it illustrates the validity of DDS. As the advantage of the programmable of FPGA,it is convenient to modify,add and optimize the functionof DDS.