【正文】 ....................................................................................................................... 1 引 言 .................................................................................................................................... 3 1 頻率計的設(shè)計原理 ................................................................................................................... 4 ............................................................................................. 4 頻率計測量周期的原理 ................................................................................................... 5 .......................................................................................... 5 ...................................................................................... 5 2 頻率計測量頻率的層次化設(shè)計方案 .......................................................................................... 6 4位十進制計數(shù)器模塊 .................................................................................................... 6 ...................................................................................... 6 4位十進制計數(shù)器的頂層設(shè)計 ............................................................................... 8 .................................................................................................................. 9 .................................................................................................... 9 D觸發(fā)器的設(shè)計 .................................................................................................. 13 ........................................................................................... 16 ............................................................................................................. 17 ............................................................................................... 17 .................................................................................................. 19 譯碼模塊 ...................................................................................................................... 21 寄存器設(shè)計 ........................................................................................................ 21 動態(tài)掃描電路 ..................................................................................................... 22 七段數(shù)碼管驅(qū)動電路的 VHDL設(shè)計 ....................................................................... 25 碼電路的設(shè)計 .................................................................................................. 26 ......................................................................................................... 28 3 頻率計測量頻率的頂層設(shè)計和仿真 ........................................................................................ 31 4 頻率計測量周期的層次化設(shè)計方 案 ........................................................................................ 32 ....................................................................................................................... 32 ....................................................................................................................... 32 ....................................................................................................................... 32 ....................................................................................................................... 36 ................................................................................................................ 38 5 頻率計測量周期頂層電路原理圖設(shè)計 ..................................................................................... 41 6 下載測試 ............................................................................................................................... 42 .............................................................................................................................. 42 ....................................................................................................................... 42 ............................................................................................................. 43 編程下載 ............................................................................................................ 43 測試 ................................................................................................................... 43 結(jié) 束 語 .................................................................................................................................... 44 致 謝 ......................................................................................................................................... 45 參考文獻： ........................................................