等精度數字頻率計

電子通信論文編號:TX080        論文字數:16039,頁數:39

目   錄

摘  要   I
ABSTRACT   II

1  緒論   1
2  系統設計方案   2
2.1系統設計方案的選擇   2
2.1.1 頻率測量模塊   2
2.1.2 周期測量模塊  4
2.1.3 脈寬測量模塊   4
2.1.4 占空比測量模塊  4
3  系統總體設計方案  5
4  CPLD/FPGA測頻專用模塊的VHDL程序設計   6
4.1 測頻模塊邏輯結構   6
4.2 各模塊功能和工作步驟如下  6
4.2.1 測頻/側周期的實現  6
4.2.2 控制部件設計  7
4.2.3 脈沖寬度測量和占空比測量模塊設計  7
4.2.4 電路顯示模塊   9
4.2.5 數碼管的編碼表   10
5  單片機控制與運算程序的設計  11
5.1 AT89C51RC單片機簡介   11
5.2 軟件調試系統   19
5.3具體試驗過程   20
5.3.1 第一次測試  20
5.3.2 第二次計算   22
5.4 系統調試的方法   23
5.4.1 調試的軟/硬件   23
5.4.2 系統的仿真結果  23
5.5 設計技巧分析  24
5.6 系統擴展思路   24
6  VHDL程序語言和FPGA簡介   29
6.1 vhdl程序語言介紹   29
6.2 FPGA 簡介  31
6.3 VHDL 在FPGA中的運用  32
結論  35
參 考 文 獻  36
附錄A：XX公式的推導  37
致 謝  38

摘  要

基于傳統測頻原理的頻率計的測量精度將隨著被測信號頻率的下降而降低，在實用中有很大的局限性，而等精度頻率計不但有教高的測量精度，而且在整個測頻區域內保持恒定的測試精度。運用等精度測量原理，結合單片機技術設計了一種數字頻率計，由于采用了屏蔽驅動電路及數字均值濾波等技術措施，因而能在較寬定的頻率范圍和幅度范圍內對頻率，周期，脈寬，占空比等參數進行測量，并可通過調整閘門時間預置測量精度。選取的這種綜合測量法作為數字頻率計的測量算法，提出了基于FPGA 的數字頻率計的設計方案。給出了該設計方案的實際測量效果，證明該設計方案切實可行，能達到較高的頻率測量精度。
 

關鍵詞  等精度測量，單片機，頻率計，閘門時間

ABSTRACT

Along with is  measured based on the traditional frequency measurement principle frequency meter measuring accuracy the signalling frequency the drop but to reduce, in is practical has the very big limitation, but and so on the precision frequency meter not only has teaches the high measuring accuracy, moreover maintains the constant test precision in the entire frequency measurement region. Using and so on the precision survey principle, unified the monolithic integrated circuit technical design one kind of numeral frequency meter, because has used the shield actuation electric circuit and technical measure and so on digital average value filter, thus could in compared in the frequency range and the scope scope which the width decided to the frequency, the cycle, the pulse width, occupied parameter and so on spatial ratio carries on the survey, and might through the adjustment strobe time initialization measuring accuracy. Selection this kind of synthesis measured the mensuration took the digital frequency meter the survey algorithm, proposed based on the FPGA digital frequency meter design proposal. Has produced this design proposal actual survey effect, proved this design proposal is practical and feasible, can achieve the high frequency measurement precision.……
 

Keywords  Precision survey, monolithic integrated circuit, frequency meter, strobe time