基于FPGA和鎖相環4046實現波形發生器

電子機電論文編號:JD166    字數:16320,頁數:43

目    錄

摘  要........................................................................... 1
Abstract ........................................................................ 2
引言 ............................................................................ 4
1 設計任務 ...................................................................... 5
1.1 基本要求....................................................................  5
1.2 發揮部分 .................................................................... 5
2 方案論證與比較 ................................................................ 5
2.1 常見信號源制作方法原理 .......................................................5
2.2 常見信號產生電路..............................................................7
3  系統電路的設計 ................................................................7
3.1 系統框圖及說明................................................................7
3.2 主要電路設計說明.............................................................10
3.2.1晶體振蕩電路................................................................10
3.2.2 倍頻電路 ..................................................................11
3.2.3 數模轉換和放大濾波電路.....................................................11
3.2.4數碼管顯示電路 .............................................................12
3.2.5 輸入去抖電路...............................................................13
3.3 主要軟件設計說明.............................................................14
3.3.1 前端核心軟件設計...........................................................14
3.3.2波形產生模塊軟件設計 .......................................................15
3.4 主要元器件介紹 ..............................................................18
3.4.1 FPGA介紹...................................................................18
3.4.3 VHDL介紹 ..................................................................22
 3.4.4 MAX+PLUSII介紹............................................................23
4  軟件仿真與硬件調試和測試......................................................23
4.1 軟件部分仿真.................................................................23
4.2 硬件調試 ....................................................................25
4.3 硬件電路測試v ...............................................................25
4.4 誤差分析 ....................................................................26
5  工程設計 .................................................................... 26
6  制作 ........................................................................ 27
7 結論 .................................................................... .....28
謝    辭 ....................................................................... 29
參考文獻 ....................................................................... 30
附  錄 ......................................................................... 31

摘  要

本設計采用FPGA和鎖相環4046實現波形發生器。系統由波形產生模塊和可調頻率的時鐘產生模塊，數模轉換模塊和顯示模塊四部分組成。波形產生模塊完成三種波形的產生，并根據控制信號完成選定波形的輸出。可調頻率的時鐘產生模塊能夠產生具有不同頻率的方波clk，用此方波作為時鐘完成輸出波形頻率的調整。顯示模塊用于顯示輸出波形的頻率。數模轉換模塊將波形產生模塊輸出的數字信號轉換為模擬信號；并完成濾波以及放大等功能。此設計的特點在于結合了直接數字頻率合成技術和鎖相技術各自的優點，同時利用了FPGA的強大處理能力使系統易于實現，結構簡單。本設計能產生正弦波，三角波，占空比可調的方波以及它們的線性組合；頻率在100Hz~20KHz之間能以100Hz為步進進行調整；幅度可調范圍為0~5V。

關鍵詞：正弦波；三角波；占空比可調的方波；頻率可調；FPGA；鎖相環4046

Abstract

The system is designed to construct an Arbitrary Waveform Generator based on DDFS,with a PLL4046 and FPGA as the key,complimented by necessary analog circuit,so the system is very simple and convenience to realize.In the design ,there are four main module.The first module is oscillator,the modules are responsible for the formation of oscillogram and prefer waveform to output,in other words it can form square waveform,sinusoid waveform and delta waveform and output one kind waveform or the linear combination of several kind waveform;so this module is the key of the system.we use FPGA to realize this module,because FPGA have enough speed and logic unit to use ,and because of its programmable attribute,we can write procedure to complete our design,it is very convenience and reliable.The second module is the control of frequency.in this module,PLL(Phase Lock Loop)4046 plays a key role,iwhich realioze the change of frequency.In fact this module is also the key of the system,if there is not this module ,the frequency of the system can’t be changed and the frequency of waveform can’t be changed,too.PLL4046 have many function,for example:multiply frequency ,modulation.now we use it to multiply frequency,so the range of system frequency  is very wide and having high definition.The third module is the digital-to-analog module.Obviously,it change the digital signal which is from the output port of FPGA into analogy signal by DAC0832,at the same time amplifer is used to amplify analogy signal and  control of its amplitude range. The last module is demonstration module,its duty is to display the frequency of waveform.Then,by cascading every module,this system is realized. At last,this system can form square waveform,sinusoid waveform and delta waveform and linear combination of them.The frequency can be adjusted from 100Hz to 15KHz,its interval is 100Hz.It can gratify the request of the design.

Keywords:：sinusoid waveform；delta  waveform ；square  waveform；FPGA；PLL4046