【正文】 ll be traveling fast, so despite the distance, it will not be like 33 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。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(qiáng)心劑，或者說(shuō)，是自以為是的精神寄托罷了。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(gè)人的時(shí)候，自己的想法總是特別地清晰。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。 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。 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(kāi)頭的年齡已經(jīng)到了尾聲。s 21 win. Michel Platini, president of European football39。s 31 antiracism taskforce, is in London for the Football Association39。t agree with the disciplinary action your employer has taken against you ? your employer dismisses you and you think that you have been dismissed unfairly. For more information about dismissal and unfair dismissal, see Dismissal. You can make a claim to an employment tribunal, even if you haven39。 我們的 學(xué)習(xí)不但要 立足于 書(shū)本 ，以解決 理論和實(shí)際 教學(xué)中的實(shí)際問(wèn)題為目的， 還要 以 實(shí)踐相結(jié)合 ， 理論 問(wèn)題即 實(shí)踐 課題， 解決問(wèn)題 即 課程研究 ， 學(xué)生自己就是一個(gè) 專家， 通過(guò)自己的手來(lái)解決問(wèn)題比用腦子解決問(wèn)題更加深刻 。 在同學(xué)及指導(dǎo)教師孔老師的一些指點(diǎn)和引導(dǎo)下，真正 培養(yǎng) 了我 運(yùn)用所學(xué)知識(shí)解決實(shí)際問(wèn)題的能力 。我在這一次畢業(yè)設(shè)計(jì)過(guò)程中，很是受益匪淺。 （ 3） 設(shè)置三個(gè)按鍵分別處理 3 種不同的緊急情況。 （ 5） 程序執(zhí)行了很長(zhǎng)時(shí)間沒(méi)結(jié)果。 （ 2） 沒(méi)有通過(guò)連接編譯。 （ 2） 跟蹤過(guò)程 此時(shí)的跟蹤程序流程，即把自己當(dāng)作計(jì)算機(jī)。 仔細(xì)檢查 K K K3 三個(gè)按鍵是否焊牢，并且三個(gè)鍵是否與相應(yīng)的 I/O 借口對(duì)應(yīng)準(zhǔn)確。若不亮，仔細(xì)查看與該腳相連的電阻及數(shù)碼管是否虛焊。 第二步：用萬(wàn)用表檢測(cè)，先用萬(wàn)用表復(fù)核目測(cè)中有疑問(wèn)的連接點(diǎn)，在檢測(cè)各種電源線與地線之間是否有短路現(xiàn)象。通過(guò) Proteus 軟件的使用我們能夠輕易地獲得一個(gè)功能齊全、實(shí)用方便的單片機(jī)實(shí)驗(yàn)室。交通燈南北綠，東西紅 MOV R7,37H PP: LCALL DISP MOV A,P3 CJNE A,0FFH,READKEY DJNZ R7,PP MOV P1,0CCH 。鍵盤(pán)掃描 CJNE A,0FFH,READKEY DJNZ R7,MM 21 MOV P1,0E1H 。啟動(dòng)定時(shí)器 T1 HERE: MOV 88H,15H 。定時(shí)器 T1 工作在方式 1 MOV TH1,9EH 。*主程序 *。定時(shí)器 T1 中斷入口 LJMP liu ORG 0100H 。查表獲取個(gè)位數(shù)的字型碼 MOV 31H,A MOV A,30H MOV P0,A 。重新給倒計(jì)時(shí)數(shù)賦初值 DIR1: MOV B,0AH DIV AB 。*顯示子程序 *。重新給循環(huán)次數(shù)賦值 LCALL DISP BN: MOV TH1,9EH 。****************。****************。東西方向亮綠燈，南北方向亮紅燈 MOV A,0FFH MOV P3,A MOV A,P3 JNB ,YY1 。******************。******************。判斷 K3 鍵是否按下 RET K1: MOV P0,0FFH 。***************。***************。*1 秒延時(shí)子程序 *。只要按規(guī)律控制各發(fā)光段亮、滅，就可 12 以顯示各種字形或符號(hào)。 LED 顯示器是現(xiàn)在最常用的顯示器之一，如圖 25所示。復(fù)位電路通常采用上電自動(dòng)復(fù)位和按鈕復(fù)位兩 11 種方式，此電路系統(tǒng)采用的是上電與按鈕復(fù)位電路。復(fù)位后 P0－ P3 口均置 1 引腳表現(xiàn)為高電平，程序計(jì)數(shù)器和特殊功能寄存器 SFR 全部清零。對(duì)外接電容的值雖然沒(méi)有嚴(yán)格的要求，但電容的大小會(huì)影響震蕩器頻率的高低、震蕩器的穩(wěn)定性、起振 的快速性和溫度的穩(wěn)定性。 AT89 單片機(jī)內(nèi)部有一個(gè)用于構(gòu)成振蕩器的高增益反相放大器。內(nèi)部方式時(shí)，時(shí)鐘發(fā)生器對(duì)振蕩脈沖二分頻， 如晶振為 12MHz，時(shí)鐘頻率就為 6MHz。然而，初始復(fù)位不改變 RAM（包括工作寄存器 R0R7）的狀態(tài)， 8052的初始態(tài) 。現(xiàn)在我們對(duì)這些引腳的功能加以說(shuō)明： 9 的引腳說(shuō)明： MCS52系列單片機(jī)中的 803 8051及 8751均采用 40Pin封裝的雙列直接 DIP結(jié)構(gòu)，右圖是它們的引腳配置， 40 個(gè)引腳中，正電源和地線兩根，外置石英振蕩器的時(shí)鐘線兩根， 4 組 8 位共 32 個(gè) I/O 口，中斷口線與 P3 口線復(fù)用。 ： 8052 內(nèi)置一個(gè)全雙工串行通信口，用于與其它設(shè)備間的串行數(shù)據(jù)傳送，該串行口既可以用作異步通信收發(fā)器，也可以當(dāng)同步移位器使用。 (RAM) 8052 內(nèi)部有 128 個(gè) 8 位用戶數(shù)據(jù)存儲(chǔ)單元和 128 個(gè)專用寄存器單元，它們是統(tǒng)一編址的，專用寄存器只能用于存放控制指令數(shù)據(jù)，用戶只能訪問(wèn)，而不能用于存放用戶數(shù)據(jù)，所以，用戶能使用的 RAM 只有 128 個(gè)，可存放讀寫(xiě)的數(shù)據(jù)，運(yùn)算的中間結(jié)果或用戶定義的字型表 。 鍵盤(pán)及狀態(tài)顯示，開(kāi)關(guān)鍵盤(pán)輸入 交通 燈初始時(shí)間，通過(guò)單片機(jī) P1 輸入到系統(tǒng)。 由于該系統(tǒng) 是 對(duì)交通燈及數(shù)碼管的控制，只 需 用單片機(jī)本身的 I/O 口就可實(shí)現(xiàn)，且本身的計(jì)數(shù)器及 RAM 已經(jīng)夠用，故 選擇 方案二。該方案的優(yōu)點(diǎn)是使用靈活可編程，并且有 RAM 及計(jì)數(shù)器。 時(shí)鐘電路 復(fù)位電路 單片機(jī) AT89C51 紅綠燈裝置 驅(qū)動(dòng)裝置 倒計(jì)時(shí)顯示裝置 6 方案二：完全采用數(shù)碼管顯示。 綜上所述，選擇第二種方案。本次設(shè)計(jì)考慮了兩種電源方案： 方案一：采用獨(dú)立的穩(wěn)壓電源。 4 目錄 摘 要 ........................................