【正文】 功耗、帶4K字節(jié)閃存可編程可擦除只讀存儲器（FPEROM—Flash Programmable and Erasable Read Only Memory）的8位CMOS單片微型計(jì)算機(jī)芯片。 圖22 AT89C51內(nèi)部框圖2）主要技術(shù)指標(biāo)和特性 指令系統(tǒng)兼容 ：1000寫/擦循環(huán) ：10年 ：0Hz24MHz 8位內(nèi)部RAM 3）引腳排列AT89C51的引腳排列見圖23。當(dāng)P0口的管腳第一次寫1時(shí)，被定義為高阻輸入。P1口管腳寫入1后，被內(nèi)部上拉為高，可用作輸入，P1口被外部下拉為低電平時(shí)，將輸出電流，這是由于內(nèi)部上拉的緣故。這是由于內(nèi)部上拉的緣故。 P3口——P3口管腳是8個(gè)帶內(nèi)部上拉電阻的雙向I/O口，可接收輸出4個(gè)TTL門電流。RST——復(fù)位輸入。——外部程序存儲器的選通信號。注意加密方式1時(shí)，將內(nèi)部鎖定為RESET；當(dāng)端保持高電平時(shí)，此間內(nèi)部程序存儲器?！脕碚{(diào)節(jié)上下限，組成按鍵輸入模塊。復(fù)位電路:單片機(jī)的復(fù)位電路見圖24。由于微機(jī)電路是時(shí)序數(shù)字電路，它需要穩(wěn)定的時(shí)鐘信號，因此在電源上電時(shí)，復(fù)位信號才被撤除，微機(jī)電路開始正常工作。圖25 時(shí)鐘電路1)DS18B20性能。 64位ROM和單線接 口 高速緩存存儲器 存儲器和控制器8位CRC生成器溫度傳感器 低溫觸發(fā)器TL高溫觸發(fā)器TH配置寄存器電源檢測I/OVDD圖26 DS18B20的內(nèi)部結(jié)構(gòu)DS18B20的外形及管腳排列見圖27。計(jì)數(shù)器1對低溫度系數(shù)晶振產(chǎn)生的脈沖信號進(jìn)行減法計(jì)數(shù)，當(dāng)計(jì)數(shù)器1的預(yù)置值減到0時(shí)，溫度寄存器的值將加1，計(jì)數(shù)器1的預(yù)置將重新被裝入，計(jì)數(shù)器1重新開始對低溫度系數(shù)晶振產(chǎn)生的脈沖信號進(jìn)行計(jì)數(shù)，如此循環(huán)直到計(jì)數(shù)器2計(jì)數(shù)到0時(shí)，停止溫度寄存器值的累加，此時(shí)溫度寄存器中的數(shù)值即為所測溫度。圖210 液晶電路接線原理圖 LM016L引腳介紹：Vss（1腳）：一般接地。E（6腳）：E(或EN)端為使能(enable)端，下降沿使能。DB3（10腳）：低4位三態(tài)、 雙向數(shù)據(jù)總線 3位。DB7（14腳）：高4位三態(tài)、 雙向數(shù)據(jù)總線 7位（最高位）。向LCD的顯示緩沖區(qū)中送字符，程序中采用2個(gè)字符數(shù)組，一個(gè)顯示字符，另一個(gè)顯示電壓數(shù)據(jù)，要顯示的字符或數(shù)據(jù)被送到相應(yīng)的數(shù)組中，,判斷是否夠顯示的個(gè)數(shù)，不夠則地址加一取下一個(gè)要顯示的字符或數(shù)據(jù)。按鍵輸入電路連接圖見圖211。也可以通過斷開與D1相連的開關(guān)，使其斷電，停止報(bào)警。主程序的主要功能是負(fù)責(zé)讀出并處理DS18B20的測量的當(dāng)前溫度值，溫度的實(shí)時(shí)顯示，并根據(jù)設(shè)置的上下限判斷是否報(bào)警。結(jié)束報(bào)警模塊，LED燈閃爍是否越限？是開始初始化調(diào)用溫度傳感器模塊DS18B2存在？錯(cuò)誤處理處理溫度值轉(zhuǎn)換送AT89C51處理按鍵掃描按鍵顯示模塊，液晶顯示否是否 圖31 主程序流程圖(二)子程序的設(shè)計(jì)讀出溫度子程序：讀出溫度子程序的主要功能是讀出RAM中的9字節(jié)，在讀出時(shí)需要進(jìn)行CRC校驗(yàn)，校驗(yàn)有錯(cuò)時(shí)不進(jìn)行溫度數(shù)據(jù)的改寫。 圖33 溫度轉(zhuǎn)換命令子程序計(jì)算溫度子程序：計(jì)算溫度子程序?qū)AM中讀取值進(jìn)行BCD碼的轉(zhuǎn)換運(yùn)算，并進(jìn)行溫度值正負(fù)的判定。Proteus軟件可以對以微控制器的設(shè)計(jì)和所有的周圍電子器件一起仿真為基礎(chǔ)，用戶甚至可以實(shí)時(shí)采用例如LED/LCD、鍵盤等動(dòng)態(tài)外設(shè)模型來對設(shè)計(jì)進(jìn)行交互的仿真。程序無誤。見圖42。將“上限減一”鍵按2下，“下限加一”鍵按6下，可以得到S=28 X=16。在這次設(shè)計(jì)中，我們運(yùn)用了以前學(xué)過的專業(yè)課知識，如：proteus仿真、源程序、模擬和數(shù)字電路知識等。在這次的課程設(shè)計(jì)中，我真正的意識到，在以后的學(xué)習(xí)中，要理論聯(lián)系實(shí)際，把我們所學(xué)的理論知識用到實(shí)際當(dāng)中，知識只有結(jié)合實(shí)踐才能化為成就與力量，這就是此次課程設(shè)計(jì)的最大收獲。 最后，再次向所有關(guān)心支持指導(dǎo)幫助過我完成論文的老師和同學(xué)，表示最誠摯的謝意！七、參考文獻(xiàn)[1][J].電子測量技術(shù), 2007，810. [2][M].北京：北京航空航天大學(xué)出版社,2004，5660. [3]楊剛,[M].北京：電子工業(yè)出版社,2004，2426.[4][M]，北京：清華大學(xué)出版社，2005，2024. [5][M]北京：國防工業(yè)出版社，2005，1419. [6][M].西安：西安電子科技大學(xué)出版社，2002，3034.為你提供優(yōu)秀的畢業(yè)論文參考資料，請您刪除以下內(nèi)容，O(∩_∩)O謝謝！！！2 Many people have the same mixed feelings when planning a trip during Golden Week. With heaps of time, the sevenday Chinese為你提供優(yōu)秀的畢業(yè)論文設(shè)計(jì)參考資料，請您刪除一下內(nèi)容，O(∩_∩)O謝謝！??！National Day holiday could be the best occasion to enjoy a destination. However, it can also be the easiest way to ruin how you feel about a place and you may bee more fatigued after the holiday, due to battling the large crowds. During peak season, a dream about a place can turn to nightmare without careful planning, especially if you travel with children and older people. As most Chinese people will take the holiday to visit domestic tourist destinations, crowds and busy traffic are inevitable at most places. Also to be expected are increasing transport and acmodation prices, with the possibility that there will be no rooms available. It is also mon that you39。Nestled close to the country39。Shutterbugs flock to see for themselves the marvel of splendid colors around the mountains and waters, many of whom have travel a long distance and even camp here only to capture a moment of the nature wonder. s misery, the cow told him to turn its hide into a pair of shoes after it died. The magic shoes whisked Niulang, who carried his two children in baskets strung from a shoulder pole, off on a chase after the empress. The pursuit enraged the empress, who took her hairpin and slashed it across the sky creating the Milky Way which separated husband from wife. But all was not lost as magpies, moved by their love and devotion, formed a bridge across the Milky Way to reunite the family. Even the Jade Emperor was touched, and allowed Niulang and Zhinu to meet once a year on the seventh night of the seventh month. This is how Qixi came to be. The festival can be traced back to the Han Dynasty (206 BCAD 220). Traditionally, people would look up at the sky and find a bright star in the constellation Aquila as well as the star Vega, which are identified as Niulang and Zhinu. The two stars shine on opposite sides of the Milky Way. Customs In bygone days, Qixi was not only a special day for lovers, but also for girls. It is also known as the Begging for Skills Festival or Daughters39。s Day! in shops, hotels and restaurants. But few young women will mark the festival with their boyfriends, or take part in traditional activities to pray for cleverness. A largescale of exhibition on the Silk Road opened to the public in the National Museum on Thursday. The exhibition displays more than 400 treasures from Shaanxi province, Gansu province and 14 other regions. It is largest scale exhibition that shows the history of the Silk Road in recent years. As16