【正文】 對于圖 214 中的 4 位顯示器，在 AT89C52RAM 存貯器中設(shè)置 4 個顯示緩沖器單元 30H－ 34H，分別存放 4 位顯示器的顯示數(shù)據(jù)，AT89C52 的 P2 口掃描輸出總是只在一位為低電平，即 4 位顯示器中僅有一位公共陰極為低電平，其它位為高電平， AT89C52 的 P0 口相應(yīng)位（陰極為低）的顯示數(shù)據(jù)的段數(shù)據(jù)，使該位顯示出一個字符，其它們 為暗，依次地改變 P2 口輸出為高的位， P0 口輸出對應(yīng)的段數(shù)據(jù)， 4 位顯示器就顯示出由緩沖器中顯示數(shù)據(jù)所確定的字符。 根據(jù)設(shè)計的要求，單片機(jī)的 任務(wù)是：內(nèi)部進(jìn)行計數(shù)，在計算出速度后顯示。此部分要反復(fù)進(jìn)行多次才能完全調(diào)試出來。通過 Project 菜單中的 New Project 命令建立項(xiàng)目文件，過程如 圖 41。如果沒有現(xiàn)成的程序，那么就要新建一個程序文件。選“ Add File to Group Source Group1 ”彈南京鐵道職業(yè)技術(shù)學(xué)院 第 20 頁 共 30 頁 20 出文件窗口，選擇剛剛保存的文件，按 Add 按鈕，關(guān)閉文件窗口，程序文件已加到項(xiàng)目中了。打開項(xiàng)目選項(xiàng)窗口，轉(zhuǎn)到 Output 選項(xiàng)頁，選擇編譯輸出的路徑，設(shè)置編譯輸出生成的文件名決定是否要創(chuàng)建 HEX 文件，選中它就可以輸出 HEX 文件到指定路徑中。它是目前最好的仿真單片機(jī)及外圍器件的工具。給出了硬件和軟件的設(shè)計方案 并通過仿真軟件進(jìn)行仿真 。系統(tǒng)在硬件設(shè)計上也充分考慮了可擴(kuò)展性，經(jīng)過簡單的修改程序，很容易實(shí)現(xiàn)功能的擴(kuò)展。本文從開題、寫作直至最終定稿， 鄭 老師給予了諸多建設(shè)性建議，并在百忙之中三閱其稿。 南京鐵道職業(yè)技術(shù)學(xué)院 第 25 頁 共 30 頁 25 附錄一 光電傳感器測轉(zhuǎn)速原理圖： P 0. 0/ A D 039P 0. 1/ A D 138P 0. 2/ A D 237P 0. 3/ A D 336P 0. 4/ A D 435P 0. 5/ A D 534P 0. 6/ A D 633P 0. 7/ A D 732P 2. 0/ A 821P 2. 1/ A 922P 2. 2/ A 1023P 2. 3/ A 1124P 2. 4/ A 1225P 2. 5/ A 1326P 2. 6/ A 1427P 2. 7/ A 1528P 3. 0/ R X D10P 3. 1/ T X D11P 3. 4/ T 014P 3. 3/ I N T 113P 3. 5/ T 115P 3. 6/ W R16P 3. 7/ R D17X T A L 119X T A L 218R S T9P S E N29A L E30EA31P 1. 0/ T 21P 1. 1/ T 2E X2P 1. 23P 1. 34P 1. 45P 1. 56P 1. 67P 1. 78P 3. 2/ I N T 057A T 89C 52U1C130pFC230pFX1C R Y S T A LV C CC310uFR 116KV C CA B C D E F DP 1 2 3 410k10kG N D 南京鐵道職業(yè)技術(shù)學(xué)院 第 26 頁 共 30 頁 26 附錄二 光電傳感器測轉(zhuǎn)速主程序： include define uchar unsigned char define uint unsigned int define ulong unsigned long define LED_DAT P1 sbit pin_SpeedSenser = P3^5。 //時間計數(shù)器 bit Flag_Fresh = 0。 //初始化定時器 T0 void init_timer0()。 //d 定時器 T0 用于數(shù)碼管的動態(tài)刷新 // TH0 = 0xC0。 if(TcounterTIME_CYLC) { Flag_clac = 1。 Disbuf[3] = 0。 // 定時刷新數(shù)碼管顯示 if(Flag_clac) { Flag_clac = 0。//脈沖計數(shù)清零 } } } //在數(shù)碼管上顯示一個四位數(shù) void DisplayFresh() { P2=P2amp。 P2=P2|0xf0。 Delay(1)。 LED_DAT = table[Disbuf[2]]。0xef。 } //計算轉(zhuǎn)速，并把結(jié)果放入數(shù)碼管緩沖區(qū) void ClacSpeed() { long speed 。//據(jù)公式計數(shù)轉(zhuǎn)速 Disbuf[0] = (speed/1000)%10。 } //初始化定時器 T0 void init_timer0() { TMOD amp。 C/T0=0。 /* init values */ TL0 = 0x00。 /* timer0 run */ } //延時函數(shù) void Delay(uint ms) { uchar i。 } //初始化定時器 T1 void init_timer1() { TMOD amp。 C/T0=1。 /* init values */ TL1 = 0x00。 /* timer1 run */ } 南京鐵道職業(yè)技術(shù)學(xué)院 第 29 頁 共 30 頁 29 附錄三系統(tǒng)實(shí)物圖： 南京鐵道職業(yè)技術(shù)學(xué)院 第 30 頁 共 30 頁 30 參考文獻(xiàn)： [1] 楊少春 傳感器原理與應(yīng)用 電子工業(yè)出版社， [2] 賈海瀛 傳感器技術(shù)與應(yīng)用 清華大學(xué)主板社， [3].何立民 單片機(jī)應(yīng)用技術(shù)選編 北京航空航天大學(xué)出版社， 1997， 10 [4].張有德 單片微機(jī)原理、應(yīng)用與實(shí)驗(yàn) 復(fù)旦大學(xué)出版社， 1997， 8 [4] 楊文龍 單片機(jī)原理及應(yīng)用系統(tǒng)設(shè)計 清華大學(xué)主板社， [6].梁廷貴、王裕琛 現(xiàn)代集成電路實(shí)用手冊 科學(xué)技術(shù)文獻(xiàn)出版 社， 1999， 6 [7].于海生 微型計算機(jī)控制技術(shù)選編 清華大學(xué)出版社， [8].徐愛鈞 智能化測量控制儀表原理與設(shè)計 北京航空航天大學(xué)出版 社， [9].周興華 手把手教你學(xué)單片機(jī) 北京航空航天大學(xué)出版社， 1996， 7 [10] 譚浩強(qiáng) C 程序設(shè)計 清華大學(xué)主板社， g an employment tribunal claim Employment tribunals sort out disagreements between employers and employees. You may need to make a claim to an employment tribunal if: ? you don39。re clear about the terms of the agreement. It might be best to get advice from an experienced adviser, for example, at a Citizens Advice Bureau. To find your nearest CAB, including those that give advice by , click on nearest CAB. For more information about making a claim to an employment tribunal, see Employment tribunals. 南京鐵道職業(yè)技術(shù)學(xué)院 第 31 頁 共 30 頁 31 The (lack of) air up there Watch mCayman Islandsbased Webb, the head of Fifa39。s about how he felt and I would like to speak to him first to find out what his experience was. Uefa has opened disciplinary proceedings against CSKA for the racist behaviour of their fans during City39。s plaint. In a statement the Russian side added: We found no racist insults from fans of CSKA. Age has reached the end of the beginning of a word. May be guilty in his seems to passing a lot of different life became the appearance of the same day。二十年的人生軌跡深深淺淺，突然就感覺到有些事情，非做不可了。或許是愧疚于自己似乎把轉(zhuǎn)瞬即逝的很多個不同的日子過成了同一天的樣子；或許是追溯過去，對自己那些近乎偏執(zhí)的怪異信念的醒悟，這些天以來，思緒一直很凌亂，在腦海中不斷糾纏。s governing body, has also ordered an immediate investigation into the referee39。s 150th anniversary celebrations and will attend City39。t appealed against the disciplinary action your employer has taken against you. However, if you win your case, the tribunal may reduce any pensation awarded to you as a result of your failure to appeal. Remember that in most cases you must make an application to an employment tribunal within three months of the date when the event you are plaining about happened. If your application is received after this time limit, the tribunal will not usually accept it. If you are worried about how the time limits apply to you, take advice from one of the anisations listed under Further help. Employment tribunals are less formal than some other courts, but it is still a legal process and you will need to give evidence under an oath or affirmation. Most people find making a claim to an employment tribunal challenging. If you are thinking about making a claim to an employment tribunal, you should get help straight away from one of the anisations listed under Further help. If you are being represented by a solicitor at the tribunal, they may ask you to sign an agreement where you pay their fee out of your pensation if you win the case. This is known as a damagesbased agreement. In England and Wales, your solicitor can39。 /* enable time