应用嵌入式微控制器的数字频率合成实现方法  

Digital Frequency Synthesis Method for Embedded Microcontrollers

作　　者：陈砚圃 刘含 郭博 石立春 CHEN Yanpu;LIU Han;GUO Bo;SHI Lichun(School of Computer Science,Xijing University,Xi’an 710123,China;School of Electronic Information,Xijing University,Xi’an 710123,China)

机构地区：[1]西京学院计算机学院,陕西西安710123 [2]西京学院电子信息学院,陕西西安710123

出　　处：《探测与控制学报》2023年第5期77-81,87,共6页Journal of Detection & Control

基　　金：国家自然科学基金项目(62275079);陕西省重点研发计划项目(2022GY-118)。

摘　　要：无需专用集成电路,仅由嵌入式微控制器实现直接数字频率合成(DDS)而生成波形信号具有经济、灵活、可靠等优点。借助嵌入式微控制器内的定时器、直接存储器存取(DMA)与数模转换(DAC)等片上外设,提出基于定时中断和DMA实现DDS生成波形信号的方法。基于定时中断实现DDS生成波形信号的方法无需借助片上DMA,对嵌入式微控制器的要求较低。基于DMA实现DDS生成信号的方法,数据从信号预存区到DAC的传送由并行于CPU工作的DMA完成,支持较高的DDS时钟频率。以正弦信号为例,采用中高端嵌入式微控制器对实现DDS生成信号的两种方法进行实验,结果表明,基于定时中断与DMA的两种方法均能生成波形优异、幅度稳定的信号,但DMA法支持更宽的信号频率范围。It is economical,flexible and reliable to generate waveform signal by realizing direct digital frequency synthesis(DDS)only by embedded microcontroller without introducing ASIC chips.With the help of on-chip peripherals such as timer,direct memory access(DMA)and digital-to-analog converter(DAC)in the embedded microcontroller,two methods of generating waveform signals by DDS based on timing interrupt or DMA were proposed.The method of DDS generating waveform signal based on timing interrupt did not need the support of on-chip DMA and high-performance embedded microcontroller.The DMA-based DDS signal generation method completed the transmission from signal storage area to DAC through the parallel work of DMA and CPU.It supported high DDS clock frequency and can generate signals in a wide frequency range.Taking the generation of sine signal as an example,two methods of signal generation were tested experimentally using the medium to high end embedded microcontroller.The experiment showed that both methods based on timer interrupt and DMA could generate signals with excellent waveform and stable amplitude,but DMA supported a wider signal frequency range.

关 键 词：直接数字频率合成 直接存储器存取 数模转换 嵌入式微控制器 

分 类 号：TN741[电子电信—电路与系统]