【正文】 allcapacity data memory can be integrated in the form of highspeed RAM MCU in order to accelerate the pace of implementation of SCM. But within the single chip RAM is used as a data memory, rather than as a cache memory (CACHE) to use. Controloriented instruction. To satisfy the control needs a stronger microcontroller logic control, especially with strong bit processing power. MCU I / O pins are usually multifunctional. Microcontroller chip pins as the limited number of pins and need to solve real contradiction between the signal line, using the method of multiplexed pin functions. In which pins function may be to set the instruction or by the state machine to distinguish. MCU external expansion capability. In some of the various functions within the application can not meet demand, can be extended in the external (such as extended ROM, RAM, I / O port, timer / counter, interrupt system, etc.), and many chip patible with mon puter interface to application systems designed to bring great convenience and flexibility. SCM is widely used in instruments and meters, household appliances, medical equipment, aerospace, specialized equipment for the intelligent management and process control and other fields, roughly divided into the following several areas: Intelligent instrumentation in the application: SCM has a small size, low power consumption, the control function is strong, expansion flexibility, miniaturization and ease of use, widely used in instrumentation, the bination of different types of sensors can be realized, such as voltage, power, frequency, humidity, temperature, flow, speed, thickness, angle, length, hardness, elements, pressure measurement of physical quantities. SCM makes use of digital instruments, intelligence, miniaturization, and capabilities than the use of electronic or digital circuits more powerful. For example, precision measurement equipment (power meter, oscilloscope, various analyzers). Application in industrial control: The MCU can constitute a variety of control systems, data acquisition systems. For example, the intelligent management of the factory assembly line, lift intelligent control, all kinds of alarm systems, and puter work constitutes a secondary control system. In Household appliances: You can say, now basically using the SCM appliance control, pliment from the electric rice, washing machines, refrigerators, air conditioners, color TV and other audio video equipment, to the electronic weighing equipment, a wide variety , everywhere. In the field of puter works and munication applications: modern munication interface with microcontroller general, you can easily municate with the puter data, puter works and munications in the application of devices provides an excellent physical condition, and now the munications equipment basically realized the MCU intelligent control, from cell phones, 模擬電梯控制系統(tǒng)設(shè)計(jì)第 23 –頁(yè) 共 33 頁(yè)telephones, small programcontrolled switches, building automation munication call system, train radio munication, to the daily work can be seen everywhere in the mobile phones, trunked mobile munication, wireless munication and so on. SCM in the field of medical devices: SCM use in medical devices is also quite extensive, such as medical ventilator, a variety of analyzers, monitors, ultrasound diagnostic equipment and hospital beds call system and so on. In addition, the microcontroller in the business, financial, scientific research, education, defense aerospace and other fields have a very wide range of uses. This design mainly AT89S51 chip. AT89S51 is a lowpower, highperformance CMOS 8 bit microcontroller chip contains 4k Bytes ISP (Insystem programmable) can be repeated 1,000 times rewritable readonly Flash program memory, the device using ATMEL39。運(yùn)城學(xué)院計(jì)算機(jī)科學(xué)與技術(shù)系畢業(yè)論文第 20 –頁(yè) 共 33 頁(yè)(2) 實(shí)驗(yàn)步驟 1) 按照系統(tǒng)硬件連線圖連好。動(dòng)態(tài)調(diào)試的一般方法是由近及遠(yuǎn)、由分到合。檢查外部的各種元件或者是電路是否有斷點(diǎn)。二層門(mén)關(guān)的聲音開(kāi)SSX2_3: CJNE A,17,ZHUAN2 。一層門(mén)關(guān)的聲音開(kāi)SSX1_3: CJNE A,17,ZHUAN2 。若按下則把對(duì)應(yīng)的紅色發(fā)光二極管點(diǎn)亮ONE: JB ,TWO LCALL YS10MS JB ,TWO 。電梯下降時(shí)則進(jìn)行 8 到 1 層按鍵的循環(huán)檢測(cè)。在單片機(jī)系統(tǒng)設(shè)計(jì)中，程序設(shè)計(jì)是重要的一環(huán)，它的質(zhì)量直接影響到整個(gè)系統(tǒng)的功能，用匯編語(yǔ)言進(jìn)行程序設(shè)計(jì)的過(guò)程大致可以分為以下幾個(gè)步驟：（1） 明確課題對(duì)程序功能、運(yùn)算精度、執(zhí)行速度等方面的要求及硬件條件。ISP 在線編程接口為 89S51 單片機(jī)提供了方便的在線編程方法。晶體可在 之間選擇。如果這些芯片復(fù)位端的復(fù)位電平與單片機(jī)的復(fù)位電平的要求一致，則可以將復(fù)位信號(hào)與之相連。當(dāng)然，LED 的電流通常較小，一般均需在回路中接上限流電阻。XTAL1：振蕩器反相放大器及內(nèi)部時(shí)鐘發(fā)生器的輸入端。此外，該引腳會(huì)被拉高，單片機(jī)執(zhí)行外部程序時(shí)，應(yīng)設(shè)置 ALE 無(wú)效。WDT 溢出將使該引腳輸出高電平，設(shè)置 SFR AUXR的 DISRTO 位（地址 8EH）可打開(kāi)或關(guān)閉該功能。在訪問(wèn) 8 位地址的外部數(shù)據(jù)存儲(chǔ)器（如執(zhí)行 MOVX Ri　指令）時(shí)，P2 口線上的內(nèi)容（也即特殊功能寄存器（SFR）區(qū)中 P2 寄存器的內(nèi)容） ，在整個(gè)訪問(wèn)期間不改變。在 Flash 編程時(shí)，P0 口接收指令字節(jié)，而在程序校驗(yàn)時(shí)，輸出指令字節(jié)，校驗(yàn)時(shí)，要求外接上拉電阻。 看門(mén)狗（ WDT）電路 2 個(gè) 16 位可編程定時(shí)/計(jì)數(shù)器 空閑模式下，CPU 暫停工作，而 RAM 定時(shí)計(jì)數(shù)器，串行口，外中斷系統(tǒng)可繼續(xù)工作。而 Microchip 公司的 PIC 精簡(jiǎn)指令集(RISC)也有著強(qiáng)勁的發(fā)展勢(shì)頭，中國(guó)臺(tái)灣的 HOLTEK 公司近年的單片機(jī)產(chǎn)量與日俱增，與其低價(jià)質(zhì)優(yōu)的優(yōu)勢(shì)，占據(jù)一定的市場(chǎng)分額。CMOS雖然功耗較低，但由于其物理特征決定其工作速度不夠高，而 CHMOS 則具備了高速和低功耗的特點(diǎn)，這些特征，更適合于在要求低功耗像電池供電的應(yīng)用場(chǎng)合。例如工廠流水線的智能化管理，電梯智能化控制、各種報(bào)警系統(tǒng)，與計(jì)算機(jī)聯(lián)網(wǎng)構(gòu)成二級(jí)控制系統(tǒng)等。要利用某型號(hào)單片機(jī)開(kāi)發(fā)自己的應(yīng)用系統(tǒng)，掌握其結(jié)構(gòu)特征和技術(shù)特征是必須的。 單片機(jī)簡(jiǎn)介 單片機(jī)是一種集成電路芯片，采用超大規(guī)模技術(shù)把具有數(shù)據(jù)處理能力(如算術(shù)運(yùn)算，邏輯運(yùn)算、數(shù)據(jù)傳送、中斷處理)的微處理器(CPU)，隨機(jī)存取數(shù)據(jù)存儲(chǔ)器(RAM)，只讀程序存儲(chǔ)器(ROM)，輸入輸出電路(I/O 口)，可能還包括定模擬電梯控制系統(tǒng)設(shè)計(jì)第 3 –頁(yè) 共 33 頁(yè)時(shí)計(jì)數(shù)器，串行通信口(SCI)，顯示驅(qū)動(dòng)電路(LCD 或 LED 驅(qū)動(dòng)電路)，脈寬調(diào)制電路(PWM)，模擬多路轉(zhuǎn)換器及 A/D 轉(zhuǎn)換器等電路集成到一塊單塊芯片上，構(gòu)成一個(gè)最小,然而完善的計(jì)算機(jī)系統(tǒng)。而單片機(jī)價(jià)格相當(dāng)便宜，如果在抗干擾功能上有所提高的話完全可以代替 PLC 實(shí)現(xiàn)對(duì)工控設(shè)備的控制。電梯是高層賓館、商店、住宅、多層倉(cāng)庫(kù)等高層建筑不可缺少的垂直方向的交通運(yùn)輸工具。 目前，由可編程控制器（PLC）或微型計(jì)算機(jī)組成的電梯運(yùn)行邏輯控制系統(tǒng)，正以很快的速度發(fā)展著。它是將計(jì)算機(jī)的基本部件微型化并集成到一塊芯片上的微型計(jì)算機(jī)，通常片內(nèi)都含有 CPU、ROM、RAM、并行 I/O、串行 I/O、定時(shí)器/計(jì)數(shù)器、中斷控制、系統(tǒng)時(shí)鐘及系統(tǒng)總線等。這里的技術(shù)特征包括功能特性、控制特性和電氣特性等等，這些信息需要從生產(chǎn)廠商的技術(shù)手冊(cè)中得到。采用單片機(jī)控制使得儀器儀表數(shù)字化、智能化、微型化，且功能比起采用電子或數(shù)字電路更加強(qiáng)大。模擬電梯控制系統(tǒng)設(shè)計(jì)第 5 –頁(yè) 共 33 頁(yè) 單片機(jī)的發(fā)展趨勢(shì)現(xiàn)在可以說(shuō)單片機(jī)是百花齊放，百家爭(zhēng)鳴的時(shí)期，世界上各大芯片制造公司都推出了自己的單片機(jī)，從 8 位、16 位到 32 位，數(shù)不勝數(shù)，應(yīng)有盡有，有與主流 C51 系列兼容的，也有不兼容的，但它們各具特色，互成互補(bǔ)，為單片機(jī)的應(yīng)用提供廣闊的天地?，F(xiàn)在的許多單片機(jī)都具有多種封裝形式，其中 SMD(表面封裝)越來(lái)越受歡迎，使得由單片機(jī)構(gòu)成的系統(tǒng)正朝微型化方向發(fā)展。AT89S51 是一個(gè)低功耗，高性能 CMOS 8 位單片機(jī)，片內(nèi)含 4k Bytes ISP(Insystem programmable)的可反復(fù)擦寫(xiě) 1000