设计背景:近年来现场可编程门阵列( FPGA) 技术得到了迅速的发展和广泛的应用, 其资源容量、工作频率以及集成度都得到了极大的提高, 使得利用FPGA 实现某些专用数字集成电路得到了大家的关注, 而基于FPGA 实现的直接数字频率合成器即DDS（Direct Digital Synthesizer）则更具其优点, 有着灵活的接口和控制方式、较短的转换时间、较宽的带宽、以及相位连续变化和频率分辨率较高等优点, 其也为设计者在此基础之上实现电路集成提供了另一种方法,同D/ A 转换器和低通滤波器( LPF) 一起便可以组成任意波形信号的发生器。-Design background: in recent years field programmable gates array (FPGA) technology obtained A rapid development and extensive application of its resource capacity, working frequency and integration have been greatly improved, make use of FPGA realizing some special Digital integrated circuit got everyone s attention, and based on FPGA realizing Direct Digital frequency Synthesizer namely Direct Digital Synthesizer (DDS) is more the advantages, has the flexible interface and the control mode, A relatively short period of time, A wide conversion bandwidth, and phase change and continuous frequency resolution higher advantages, its also to designers based on integrated circuit to realize provides an alternative method, with the D/A converter and low pass filter (together) and can form LPF of arbitrary wave form of signal generator.