基于FPGA的数字频率计设计毕业论文

武汉轻工大学

毕业设计外文参考文献译文本

2013届

原文出处：from Vin Skahill.VHDL for Programmable Logic page 76-88

毕业设计题目：基于FPGA的数字频率计设计

院（系）：电气与电子工程学院

专业名称：电子信息科学与技术

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学生学号：

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Introduction of digital frequency meter

Digital Frequency is an indispensable instrument of communications equipment, audio and video, and other areas of scientific research and production . In addition to the plastic part of the measured signal, and digital key for a part of the show, all the digital frequency using Verilog HDL designed and implemented achieve in an FPGA chip. The entire system is very lean, flexible and have a modification of the scene.

1 、And other precision measuring frequency Principle

Frequency measurement methods can be divided into two kinds:

(1) direct measurement method, that is, at a certain time measurement gate measured pulse signal number.

(2) indirect measurements, such as the cycle frequency measurement, VF conversion law. Frequency Measurement indirect measurement method applies only to low-frequency signals.

Based on the principles of traditional frequency measurement of the frequency of measurement accuracy will be measured with the decline in signal frequency decreases in the more practical limitations, such as the accuracy and frequency of measurement not only has high accuracy, but also in the whole frequency region to maintain constant test accuracy. The main method of measurement frequency measurement Preferences gated signal GATE issued by the MCU, GATE time width on the frequency measurement accuracy of less impact, in the larger context of choice, as long as the FPGA in 32 of 100 in the counter b M Signals are not overflow line, in accordance with the theoretical calculation GATE time can be greater than the width Tc 42.94 s, but due to the single-chip microcomputer data processing capacity constraints, the actual width of less time, generally in the range of between 0.1 s choice, that is, high-frequency, shorter gate;, low gate longer. This time gate width Tc based on the size of the measured frequency automatically adjust frequency measurement in order to achieve the automatic conversion range, and expanded the range of frequency measurement; realization of the entire scope of measurement accuracy, reduce the low-frequency measurement error.

The design of the main methods of measuring the frequency measurement and control block diagram as shown in Figure 1. Figure 1 Preferences gated signal GA TE issued by the MCU, GA TE time width of less frequency measurement accuracy, in the larger context of choice, as long as the FPGA in 32 of 100 in the counter b M