基于FPGA的数字频率计设计与仿真

发布时间：2018-04-20 01:38

本文选题：频率测量 + FPGA　；参考：《黑龙江大学》2015年硕士论文

【摘要】：本文综述了频率计的发展,介绍了测量频率的常用方法,并进行优缺点比较后,选择脉冲计数法作为本次设计的方法。由于计数法中内部计数器的个数决定了频率计的总量程,设计上中选择七个计数器作为频率计测量单位。阐述了查找表原理和结构,给出了组合逻辑电路当中,如果输入量固定,那么输出量也是相对固定的原理。对FPGA的数字逻辑实现原理进行了相关分析,通过进位逻辑将多个单元相连,可以由FPGA来实现复杂的逻辑,最后采用Verilog语言对数字频率计各功能模块和系统进行了设计仿真。本文在Quartus II软件平台上,采用Verilog语言设计了一种频率范围为1Hz~100MHz的高精度数字频率计,频率测量的相对误差小于10-5,对本文设计的数字频率计进行了优化,降低了频率计的可见误差,提高频率测量精度,为了在1Hz~100MHz频率范围内能够达到较小的误差,本文以100kHz为分界点,当被测信号频率小于100kHZ趋向低频时,采用测周法,而当被测信号频率大于100kHz时趋向高频时,使用测频法使测量精度更高,最终测量精度基本达到设计要求。
[Abstract]:In this paper, the development of frequency meter is reviewed, and the common methods of frequency measurement are introduced. After comparing the advantages and disadvantages, the pulse counting method is selected as the method of this design. Because the number of internal counters in the counting method determines the total process of the cymometer, seven counters are chosen as the measuring units of the cymometer in the design. The principle and structure of look-up table are expounded. The principle of relative fixed output is given in combinatorial logic circuit if input is fixed. This paper analyzes the realization principle of digital logic of FPGA, connects several units through carry logic, and realizes complex logic by FPGA. Finally, the function modules and systems of digital frequency meter are designed and simulated by Verilog language. In this paper, a high precision digital cymometer with frequency range of 1Hz~100MHz is designed by using Verilog language on Quartus II software platform. The relative error of frequency measurement is less than 10 ~ (-5). The digital cymometer designed in this paper is optimized. The visible error of the cymometer is reduced, and the accuracy of frequency measurement is improved. In order to achieve a smaller error in the frequency range of 1Hz~100MHz, in this paper, when the frequency of the measured signal is less than the low frequency of 100kHZ, the cycle measurement method is adopted when the frequency of the measured signal is less than the low frequency of 100kHZ. When the signal frequency is larger than 100kHz, the frequency measurement method is used to make the measurement accuracy higher, and the final measurement precision basically meets the design requirements.
【学位授予单位】：黑龙江大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TM935.133;TN791

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