【正文】 則轉(zhuǎn)第三行。送掃描的首列。調(diào)用按鍵總掃描程序，無按鍵則繼續(xù)查詢 JNZ LK1 。按鍵掃描子程序。節(jié)省 I/O 口。使用時公共端接高電平（ 51 單 片機系統(tǒng)中通常為＋ 5V）。 LED 數(shù)碼顯示原理 （ 1） LED 數(shù)碼管顯示原理 通常所說的的 LED 顯示器由 7 個發(fā)光二極管組成，因此也稱之為七段數(shù)碼顯示器，其排列形狀如圖 2。若要求更高精度 ,可從本端輸入外部時鐘 (如附錄所列 )。 EOM 標(biāo)志 只在放音中檢測到內(nèi)部的 EOM 標(biāo)志時 ,此狀態(tài)位才置 1。 ISD 未選中時 ,本端呈高阻態(tài)。 同相模擬輸入 (ANA IN+) 這是錄音信號的同相輸入端。 總體設(shè)計方案框圖及分析 總方案框圖分語音報站框圖和 LED 顯示框圖，其中語音報站以 ISD4004 語音 芯片 為主體，顯示部分以矩陣式鍵盤和 LED 顯示器為主體，兩者均與單片機相連接。設(shè)計時需 對單片機進行程序設(shè)計，處理好系統(tǒng) 人機交互界面 。 實施“公交優(yōu)先”是解決我國城市交通發(fā)展問題的有效途徑，也是我國目前城市交通發(fā)展的基本政策。 畢業(yè)設(shè)計用紙 共 頁 第 頁 中文摘要 本設(shè)計主要解決如何方便、準(zhǔn)確地指示乘客到站的問題，具有模擬人聲進行報站和預(yù)報站，對所報站數(shù)和站名進行文字顯示和站名語音信息錄放及站名選擇控制等功能。 近年來，我國城市交通的現(xiàn)狀已引起了政府、公眾、社會各界的廣泛關(guān)注， 有關(guān)專家學(xué)者和交通工程師們在吸取各國城市交通發(fā)展經(jīng)驗的基礎(chǔ)上，找到了一條解決我國城市交通發(fā)展問題的有效途徑，即優(yōu)先發(fā)展城市公共交通，以公共交通為杠桿降低城市交通需求總量，實現(xiàn)道路交通基礎(chǔ)設(shè)施發(fā)展與交通需求增長的均衡。 公共汽車語音報站器主要利用 51 單片機以及 ISD4004 模擬公交車 語音報站系統(tǒng) 。本次設(shè)計主要利用 51單片機以及 ISD4004 模擬公交車 語音報站 器 。 地線 :(VSSA,VSSD) 芯片內(nèi)部的模擬和數(shù)字電路也使用不同的地線。 串行輸出 (MISO) ISD 的串行輸出端。 OVF 標(biāo)志 指示 ISD 的錄、放操作已到達存儲器的未尾。工業(yè)級芯片在整個溫度和電壓范圍內(nèi) ,頻率變化在 6/+4%內(nèi) ,此時建議使用穩(wěn)壓電源。 SPI 協(xié)議是一個同步串行數(shù)據(jù)傳輸協(xié)議 ,協(xié)議假定微控制ISD4004 畢業(yè)設(shè)計用紙 共 頁 第 頁 器的 SPI 移位寄存器在 SCLK 的下降沿動作 ,因此對 ISD4003 而言 ,在時鐘止升沿鎖存 MOSI引腳的數(shù)據(jù) ,在下降沿將數(shù)據(jù)送至 MISO 引腳。 （ 3） LED 顯示器中的發(fā)光二極管共有兩種連接方法： ? 共陽極接法 把發(fā)光二極管的陽極連在一起構(gòu)成公共陽極。矩陣式鍵盤適用于按鍵數(shù)量較多的場合，由行線和列線組成，按鍵位于行列的交叉點上。 第 三 章 程序設(shè)計 程序流程圖 畢業(yè)設(shè)計用紙 共 頁 第 頁 圖 6 公交車語音報站系統(tǒng)程序流程 源程序清單 。初始化數(shù)碼管滅 MOV DIS_GE , 0AH LCALL DISPLAY MAIN: LCALL KEY1 MOV A , R3 MOV B , 10 DIV AB MOV DIS_SHI , A MOV DIS_GE , B LCALL DISPLAY SJMP MAIN 畢業(yè)設(shè)計用紙 共 頁 第 頁 KEY1: LCALL KS1 。 AJMP KEY1 LK2: MOV R2 , 0FEH 。 MOV A , 04H AJMP LKP LTWO: JB , LTHREE 。進行下一列的掃描。 DB 0c0h ,0f9h ,0a4h ,0b0h ,99h ,92h ,82h ,0f8h ,80h ,90h ,0FFH。 在此感謝老師們的指導(dǎo)和幫助，感謝老師們傳授給我的知識，指導(dǎo)老師的嚴(yán)謹(jǐn)和求實的治學(xué)精神 及踏實細(xì)致的科研態(tài)度使我受益非淺。s antiracism taskforce, is in London for the Football Association39。 May be back in the past, to oneself the paranoid weird belief disillusionment, these days, my mind has been very messy, in my mind constantly. Always feel oneself should go to do something, or write something. Twenty years of life trajectory deeply shallow, suddenly feel something, do it. 一字開頭的年齡已經(jīng)到了尾聲。t want to give vent to out your inner voice can be in the high school children of the feelings in a period, but was eventually infarction when graduation party in the throat, later again stood on the pitch he has sweat profusely, looked at his thrown a basketball hoops, suddenly found himself has already can39。那些曾經(jīng)所謂的非做不可，只是青蔥年華里自己給自己注射的一支強心劑，或者說，是自以為是的精神寄托罷了。ll be traveling fast, so despite the distance, it will not be like 畢業(yè)設(shè)計用紙 共 頁 第 頁 diving into the deep end of a pool. It will be like he is diving into the shallow end. Skydiver preps for the big jump When he jumps, he is expected to reach the speed of sound 690 mph (1,110 kph) in less than 40 seconds. Like hitting the top of the water, he will begin to slow as he approaches the more dense air closer to Earth. But this will not be enough to stop him pletely. If he goes too fast or spins out of control, he has a stabilization parachute that can be deployed to slow him down. His team hopes it39。 Have declared the end of the encounter that haven39。s time, your ideas are always special to clear. Want, want, line is clear, as if nothing could shake his. Also once seemed to be determined to do something, but more often is he backed out at last. Dislike his cowardice, finally found that there are a lot of love, there are a lot of miss, like shadow really have been doomed. Those who do, just green years oneself give oneself an arm injection, or is a selfrighteous spiritual. 一個人的時候，自己的想法總是特別地清晰。 The end of our life, and can meet many things really do? 而窮盡我們的一生，又能遇到多少事情是真正地非做不可？ During my childhood, think lucky money and new clothes are necessary for New Year, but as the advance of the age, will be more and more found that those things are optional。s 21 win. Michel Platini, president of European football39。t agree with the disciplinary action your employer has taken against you ? your employer dismisses you and you think that you have been dismissed u