安徽工程大學(xué)機(jī)電學(xué)院畢業(yè)設(shè)計(jì)(論文)開題報(bào)告題目單片機(jī)控制的自行車速度、里程表的設(shè)計(jì)學(xué)生姓名羅偉勝學(xué)號313107010417專業(yè)自動(dòng)化一、本課題的研究意義、研究現(xiàn)狀和發(fā)展趨勢（文獻(xiàn)綜述）1.1論文的研究意義自1886年發(fā)明汽車以來,汽車走過了100多年的發(fā)展歷程。但是隨著科技發(fā)展和環(huán)境變化，人們越來越注重環(huán)保，自行車的使用趨勢逐漸增加。因?yàn)樽孕熊囀褂煤喴追奖?，環(huán)保安全，不易擁堵等諸多優(yōu)點(diǎn)被越來越多的人們接受和喜歡。傳統(tǒng)的汽車轉(zhuǎn)速里程表的功能有兩個(gè)，一是用指針指示汽車行駛的瞬時(shí)車速，二是用機(jī)械計(jì)數(shù)器記錄汽車行駛的累計(jì)里程?，F(xiàn)代汽車正向高速化方向發(fā)展,隨著車速的提高，用軟軸驅(qū)動(dòng)的傳統(tǒng)車速里程表受到前所未有的挑戰(zhàn)。這是因?yàn)檐涊S在高速旋轉(zhuǎn)時(shí)，由于受鋼絲交變應(yīng)力極限的限制而容易斷裂，同時(shí)，軟軸布置過長會出現(xiàn)形變過大或運(yùn)動(dòng)遲滯等現(xiàn)象,而且,對于不同的車型,轉(zhuǎn)速里程表的安裝位置也會受到軟軸長度及彎曲度的限制。凡此種種,使得基于非接觸式轉(zhuǎn)速傳感器的電子式轉(zhuǎn)速里程表得以迅速發(fā)展。隨著居民生活水平的不斷提高，自行車不再僅僅是普通的運(yùn)輸、代步的工具，而是成為人們娛樂、休閑、鍛煉的首選。自行車?yán)锍瘫砟軌驖M足人們最基本的需求，讓人們能清楚地知道當(dāng)前的速度、里程等物理量。主要闡述一種基于霍爾元件的自行車?yán)锍瘫淼脑O(shè)計(jì)。以 AT89C52 單片機(jī)為核心，A44E 霍爾傳感器測轉(zhuǎn)數(shù)，實(shí)現(xiàn)對自行車?yán)锍?速度的測量統(tǒng)計(jì)，采用 24C02 實(shí)現(xiàn)在系統(tǒng)掉電的時(shí)候保存里程信息，并能將自行車的里程數(shù)及速度用LED實(shí)時(shí)顯示。文章詳細(xì)介紹了自行車?yán)锍瘫淼挠布娐泛蛙浖O(shè)計(jì)。硬件部分利用霍爾元件將自行車每轉(zhuǎn)一圈的脈沖數(shù)傳入單片機(jī)系統(tǒng)，然后單片機(jī)系統(tǒng)將信號經(jīng)過處理送顯示。軟件部分用匯編語言進(jìn)行編程，采用模塊化設(shè)計(jì)思想。該系統(tǒng)硬件電路簡單，子程序具有通用性，完全符合設(shè)計(jì)要求。1.2單片機(jī)控制自行車速度、里程表的發(fā)展現(xiàn)狀傳統(tǒng)的轉(zhuǎn)速里程表的功能有兩個(gè)，一是用指針指示車輛行駛的瞬時(shí)車速，二是用機(jī)械計(jì)數(shù)器記錄車輛行駛的累計(jì)里程?，F(xiàn)代車輛正向高速化方向發(fā)展,隨著車速的提高，用軟軸驅(qū)動(dòng)的傳統(tǒng)車速里程表受到前所未有的挑戰(zhàn)。這是因?yàn)檐涊S在高速旋轉(zhuǎn)時(shí)，由于受鋼絲交變應(yīng)力極限的限制而容易斷裂，同時(shí)，軟軸布置過長會出現(xiàn)形變過大或運(yùn)動(dòng)遲滯等現(xiàn)象。凡此種種,使得基于非接觸式轉(zhuǎn)速傳感器的電子式轉(zhuǎn)速里程表得以迅速發(fā)展。在其工作原理上作出技術(shù)創(chuàng)新,即徹底放棄了“動(dòng)磁式”或“動(dòng)圈式”模擬電子式儀表，通過線包與磁鋼間產(chǎn)生電磁轉(zhuǎn)矩驅(qū)動(dòng)指針工作的形式。該儀表由傳感器完成各種被測物理量的采集，經(jīng)過換算后直接送入單片機(jī)，再由驅(qū)動(dòng)器驅(qū)動(dòng)指針，在刻度盤上指示被測物理量，同時(shí)輔以被測物理量LCD數(shù)字顯示。該汽車儀表在指示方式上仍然保留了第3代儀表指示直觀、有動(dòng)感、符合日常習(xí)慣等特點(diǎn)，而且批量生產(chǎn)的成本有望低于同等功能的模擬電子式儀表，更可貴的是在工作原理上的創(chuàng)新和突破，帶來了技術(shù)性能質(zhì)的提高。全數(shù)字式汽車儀表后，未來汽車儀表應(yīng)向何方向發(fā)展呢？雖然具體過程不清楚，但總的趨勢還是比較明朗的，那就是充分應(yīng)用光技術(shù)和機(jī)、電一體化技術(shù)，并突出現(xiàn)代信息技術(shù)和網(wǎng)絡(luò)技術(shù)的應(yīng)用，其功能將極大拓寬，指示形式將演變成計(jì)算機(jī)終端顯示器。雖然人們對未來汽車儀表作出種種預(yù)測，并賦予它遠(yuǎn)遠(yuǎn)超出現(xiàn)在汽車儀表多得多的功能。個(gè)人認(rèn)為僅從技術(shù)本身的角度出發(fā)，就目前技術(shù)條件而言，實(shí)現(xiàn)這些功能并沒有什么問題，制約新技術(shù)在汽車儀表上應(yīng)用的主要因素是制造成本。因?yàn)槠噧x表是一個(gè)量大、對成本極為敏感的產(chǎn)品，在其改進(jìn)和創(chuàng)新的過程中，不僅要考慮技術(shù)的可行性、功能的拓寬、性能的改善、使用的可靠性等，更重要的是其制造成本。脫離制造成本談汽車儀表，那只能是概念性的汽車儀表。在有關(guān)技術(shù)使用費(fèi)用，特別是其依賴硬件成本進(jìn)一步降低的前提下，汽車儀表未來可能發(fā)展趨勢如下。1.3直流穩(wěn)壓電源的發(fā)展趨勢1.從近期來看，未來車輛儀表的功能將不局限于現(xiàn)在的車速、里程，可能增添如下功能。（1） 能指示安全系統(tǒng)運(yùn)行狀態(tài)，如輪胎氣壓、制動(dòng)裝置等。這些信號傳輸形式，將不再是簡單的開關(guān)接通和斷開直流信號，而是包含反映這些安全裝置工作狀態(tài)較多信息的調(diào)制信號，供單片機(jī)讀取，以便單片機(jī)能準(zhǔn)確地綜合判斷這些安全裝置的工作狀態(tài)，并給出故障顯示提醒駕駛員，或指導(dǎo)維修人員排除故障，也就是說帶基于單片機(jī)的儀表將有一定水平的智能化。（2） 將防盜系統(tǒng)納入儀表單片機(jī)的監(jiān)管下，如車座、后行李箱等處防盜鎖指紋識別開啟系統(tǒng)，防撬振動(dòng)報(bào)警裝置，防盜點(diǎn)火起動(dòng)裝置等。2.隨著顯示器件，如液晶顯示器件的性能，特別是工作溫度范圍的拓寬，在價(jià)格進(jìn)一步降低的前提下，儀表的功能將被極大地拓寬，形式將發(fā)生根本改變，外觀上就是一個(gè)高清晰度的計(jì)算機(jī)顯示器。（1） 顯示選用高效冷光源發(fā)光器件，如LCD、LED、電致發(fā)光器件等。導(dǎo)光系統(tǒng)更多體現(xiàn)出光學(xué)領(lǐng)域的新技術(shù)，如儀表面板顏色可變等滿足個(gè)性化要求設(shè)計(jì)等。3.自動(dòng)導(dǎo)航和定位系統(tǒng)可能也是未來汽車儀表上不可缺少的部分，包括全球衛(wèi)星定位系統(tǒng)和電子地圖等。4.具備完善的通訊系統(tǒng)，將來車輛上的計(jì)算機(jī)系統(tǒng)會與公共互連網(wǎng)相連，以便充分共享信息資源，處理通訊作業(yè)將是儀表計(jì)算機(jī)系統(tǒng)工作內(nèi)容的一部分。5 .儀表的計(jì)算機(jī)系統(tǒng)具備對路況設(shè)備進(jìn)行監(jiān)管的功能，可以自動(dòng)控制輪胎等其他硬件對不同路面的適應(yīng)。以上在基于當(dāng)今成熟技術(shù)的基礎(chǔ)上，對未來車輛儀表的發(fā)展方向做些簡單設(shè)想。也許，未來車輛儀表的發(fā)展將遠(yuǎn)遠(yuǎn)超出我們今天的想象。在當(dāng)今世界范圍內(nèi)，車輛儀表正處于技術(shù)更新的轉(zhuǎn)型期。為此，業(yè)內(nèi)人士和專家對此都給予極大關(guān)注。什么樣的儀表是今后車輛儀表的主流產(chǎn)品，什么技術(shù)是今后車輛儀表的主導(dǎo)技術(shù)，對于這些問題業(yè)內(nèi)人士的看法可能不盡相同，但有一點(diǎn)是肯定的，帶有基于單片機(jī)的數(shù)字技術(shù)在車輛儀表上的廣泛應(yīng)用，將是車輛儀表發(fā)展的必然。原因主要有4點(diǎn)：1.儀表的功能由軟件和硬件共同實(shí)現(xiàn)，而且主要是通過軟件實(shí)現(xiàn)。這對于量大且對成本極為敏感的車輛儀表有特殊意義，因?yàn)檐浖拈_發(fā)費(fèi)用分?jǐn)偟矫總€(gè)儀表上是非常少的。2.與僅由電子線路硬件組成的車輛儀表相比，帶有基于單片機(jī)的汽車儀表，其功能的實(shí)現(xiàn)手段更加靈活多樣。3.產(chǎn)品的“柔性”更好，即在推出新款產(chǎn)品時(shí)，能最大限度地利用以前產(chǎn)品的硬、軟件設(shè)計(jì)成果，僅做少量修改便可，這在產(chǎn)品更新?lián)Q代很快的今天和未來特別重要。4.隨著車輛電子化水平的提高，必須要求車輛儀表與車輛上其它裝置交換數(shù)據(jù)。二、主要設(shè)計(jì)（研究）內(nèi)容本課題研究的主要內(nèi)容是設(shè)計(jì)一個(gè)能夠?qū)崟r(shí)顯示速度和里程的自行車速度里程表。該里程表能夠滿足自行車騎行者在騎行過程中能夠準(zhǔn)確的了解自行車的行駛狀態(tài)和已行駛的里程數(shù)，提高騎行者的便捷性、安全性和趣味性。三、研究方案及工作計(jì)劃（含工作重點(diǎn)與難點(diǎn)及擬采用的途徑）3.1研究方案圖1 系統(tǒng)控制示意圖3.2工作計(jì)劃第一周：對畢業(yè)設(shè)計(jì)題目進(jìn)行選題；第二周：對選題進(jìn)行分析，收集資料，填寫畢業(yè)設(shè)計(jì)任務(wù)書；第三周：對畢業(yè)設(shè)計(jì)文章排版、格式進(jìn)行指導(dǎo)，準(zhǔn)備開題；第四周：認(rèn)真填寫開題報(bào)告將情況匯報(bào)指導(dǎo)老師，遞交開題報(bào)告與進(jìn)度表；第五周：進(jìn)行畢業(yè)設(shè)計(jì)正文部分，確定設(shè)計(jì)方案；第六周：對常用軟件進(jìn)行學(xué)習(xí)，導(dǎo)師進(jìn)行指導(dǎo)；第七周：整理資料、撰寫畢業(yè)設(shè)計(jì)論文（一）；第八周：完成畢業(yè)設(shè)計(jì)（論文）初稿，指導(dǎo)教師審查初稿，提出修改意見；第九周：完成畢業(yè)設(shè)計(jì)（論文）修改稿一，導(dǎo)師審查修改稿一；第十周：向指導(dǎo)教師匯報(bào)設(shè)計(jì)完成進(jìn)度，同時(shí)進(jìn)行論文中期檢查；第十一周：完成畢業(yè)設(shè)計(jì)（論文）修改稿二，指導(dǎo)教師審查修改稿二；第十二周：整理資料、按導(dǎo)師建議修改畢業(yè)設(shè)計(jì)論文（二）；第十三周：完成設(shè)計(jì)論文（電子版）初稿；第十四周：進(jìn)行畢業(yè)設(shè)計(jì)論文修訂；第十五周：畢業(yè)設(shè)計(jì)論文（打印版）最終定稿，參加論文互評；第十六周：提交畢業(yè)設(shè)計(jì)論文（打印版），參加畢業(yè)答辯；四、閱讀的主要參考文獻(xiàn)（不少于10篇，期刊類文獻(xiàn)不少于7篇，應(yīng)有一定數(shù)量的外文文獻(xiàn)）1陳偉.基于單片機(jī)的測速儀J. 電子制作，2008,10:29-30.,2姚金明，楊俊杰.自行車轉(zhuǎn)速里程表的設(shè)計(jì)J. 上海電力學(xué)院報(bào)，2013，03：249-252+265.3Krassimir T，Atanassov，Nikolai G.etal.Remark on Two Operations Over Intuitionistic Fuzzy SetsJ. Fuzziness and Knowledge-Based Systems，2010，9(1)4徐麗萍.基于AT89S51單片機(jī)自行車?yán)锍?速度計(jì)的設(shè)計(jì)J. 南京工業(yè)職業(yè)技術(shù)學(xué)院學(xué)報(bào)，2010，02：28-29.5賀穎，李盼，王志蘭.自行車智能測速器的設(shè)計(jì)J. 自動(dòng)化與儀器儀表6李華.MCS-51系列單片機(jī)使用接口技術(shù)M.北京航空航天大學(xué)出版社，19937刁文興.自行車電子里程表的初步設(shè)計(jì).南京工業(yè)技術(shù)職業(yè)技術(shù)學(xué)院學(xué)報(bào)，2004，6:25-288謝維成，楊加國.單片機(jī)原理與應(yīng)用及C51程序設(shè)計(jì).清華大學(xué)出版社。20069安宗權(quán).電動(dòng)電子車速里程表轉(zhuǎn)速表的設(shè)計(jì).沈陽建筑學(xué)院學(xué)報(bào),2002,4:145-14810張友德，趙志英等.單片機(jī)微機(jī)原理，應(yīng)用與實(shí)驗(yàn)M上海：復(fù)旦大學(xué)出版社，2003:122-13611Slotine, Weiping.Adaptive manipulator control: A case study J. Transactions on Automatic Control, 1995, 33(11): 995-102212謝自美.電子線路實(shí)驗(yàn)室側(cè)M.武漢：華中科技大學(xué)出版社，2000:212-230Microcomputer Systems Electronic systems are used for handing information in the most general sense; this information may be telephone conversation, instrument read or a companys accounts, but in each case the same main type of operation are involved: the processing, storage and transmission of information. in conventional electronic design these operations are combined at the function level; for example a counter, whether electronic or mechanical, stores the current and increments it by one as required. A system such as an electronic clock which employs counters has its storage and processing capabilities spread throughout the system because each counter is able to store and process numbers. Present day microprocessor based systems depart from this conventional approach by separating the three functions of processing, storage, and transmission into different section of the system. This partitioning into three main functions was devised by Von Neumann during the 1940s, and was not conceived especially for microcomputers. Almost every computer ever made has been designed with this structure, and despite the enormous range in their physical forms, they have all been of essentially the same basic design. In a microprocessor based system the processing will be performed in the microprocessor itself. The storage will be by means of memory circuits and the communication of information into and out of the system will be by means of special input/output(I/O) circuits. It would be impossible to identify a particular piece of hardware which performed the counting in a microprocessor based clock because the time would be stored in the memory and incremented at regular intervals but the microprocessor. However, the software which defined the systems behavior would contain sections that performed as counters. The apparently rather abstract approach to the architecture of the microprocessor and its associated circuits allows it to be very flexible in use, since the system is defined almost entirely software. The design process is largely one of software engineering, and the similar problems of construction and maintenance which occur in conventional engineering are encountered when producing software. The figure1.1 illustrates how these three sections within a microcomputer are connected in terms of the communication of information within the machine. The system is controlled by the microprocessor which supervises the transfer of information betweenitself and the memory and input/output sections. The external connections relate to the rest (that is, the non-computer part) of the engineering system. Fig.1.1 Three Sections of a Typical Microcomputer Although only one storage section has been shown in the diagram, in practice two distinct types of memory RAM and ROM are used. In each case, the word memory is rather inappropriate since a computers memory is more like a filing cabinet in concept; information is stored in a set of numbered boxes and it is referenced by the serial number of the box in question. Microcomputers use RAM (Random Access Memory) into which data can be written and from which data can be read again when needed. This data can be read back from the memory in any sequence desired, and not necessarily the same order in which it was written, hence the expression random access memory. Another type of ROM (Read Only Memory) is used to hold fixed patterns of information which cannot be affected by the microprocessor; these patterns are not lost when power is removed and are normally used to hold the program which defines the behavior of a microprocessor based system. ROMs can be read like RAMs, but unlike RAMs they cannot be used to store variable information. Some ROMs have their data patterns put in during manufacture, while others are programmable by the user by means of special equipment and are called programmable ROMs. The widely used programmable ROMs are erasable by means of special ultraviolet lamps and are referred to as EPROMs, short for Erasable Programmable Read Only Memories. Other new types of device can be erased electrically without the need for ultraviolet light, which are called Electrically Erasable Programmable Read Only Memories, EEPROMs. The microprocessor processes data under the control of the program, controlling the flow of information to and from memory and input/output devices. Some input/output devices are general-purpose types while others are designed for controlling specialhardware such as disc drives or controlling information transmission to other computers. Most types of I/O devices are programmable to some extent, allowing different modes of operation, while some actually contain special-purpose microprocessors to permit quite complex operations to be carried out without directly involving the main microprocessor. The microprocessor processes data under the control of the program, controlling the flow of information to and from memory and input/output devices. Some input/output devices are general-purpose types while others are designed for controlling special hardware such as disc drives or controlling information transmission to other computers. Most types of I/O devices are programmable to some extent, allowing different modes of operation, while some actually contain special-purpose microprocessors to permit quite complex operations to be carried out without directly involving the main microprocessor. The microprocessor , memory and input/output circuit may all be contained on the same integrated circuit provided that the application does not require too much program or data storage . This is usually the case in low-cost application such as the controllers used in microwave ovens and automatic washing machines . The use of single package allows considerable cost savings to e made when articles are manufactured in large quantities . As technology develops , more and more powerful processors and larger and larger amounts of memory are being incorporated into single chip microcomputers with resulting saving in assembly costs in the final products . For the foreseeable future , however , it will continue to be necessary to interconnect a number of integrated circuits to make a microcomputer whenever larger amounts of storage or input/output are required. Another major engineering application of microcomputers is in process control. Here the presence of the microcomputer is usually more apparent to the user because provision is normally made for programming the microcomputer for the particular application. In process control applications the benefits lf fitting the entire system on to single chip are usually outweighed by the high design cost involved, because this sort lf equipment is produced in smaller quantities. Moreover, process controllers are usually more complicated so that it is more difficult to make them as single integrated circuits. Two approaches are possible; the controller can be implemented as a general-purpose microcomputer rather like a more robust version lf a hobby computer, or as a packaged system, signed for replacing controllers based on older technologies such as electromagnetic relays. In the former case the system would probably be programmed in conventional programming languages such as the ones to9 be introduced later, while in the other case a special-purpose language might be used, for example one which allowed the function of the controller to be described in terms of relay interconnections, In either case programs can be stored in RAM, which allows them to be altered to suit changes in application, but this makes the overall system vulnerable to loss lf power unless batteries are used to ensure continuity of supply. Alternatively programs can be stored in ROM, in which case they virtually become part of the electronic hardware and are often referred to as firmware. More sophisticated process controllers require minicomputers for their implementation, although the use lf large scale integrated circuits the distinction between mini and microcomputers, Products and process controllers of various kinds represent the majority of present-day microcomputer applications, the exact figures depending on ones interpretation of the word product. Virtually all engineering and scientific uses of microcomputers can be assigned to one or other of these categories. But in the system we most study Pressure and Pressure Transmitters. Pressure arises when a force is applied over an area. Provided the force is one Newton and uniformly over the area of one square meters, the pressure has been designated one Pascal. Pressure is a universal processing condition. It is also a condition of life on the planet: we live at the bottom of an atmospheric ocean that extends upward for many miles. This mass of air has weight, and this weight pressing downward causes atmospheric pressure. Water, a fundamental necessity of life, is supplied to most of us under pressure. In the typical process plant, pressure influences boiling point temperatures, condensing point temperatures, process efficiency, costs, and other important factors. The measurement and control of pressure or lack of it-vacuum-in the typical process plant is critical. The working instruments in the plant usually include simple pressure gauges, precision recorders and indicators, and pneumatic and electronic pressure transmitters. A pressure transmitter makes a pressure measurement and generates either a pneumatic or electrical signal output that is proportional to the pressure being sensed. In the process plant, it is impractical to locate the control instruments out in the place near the process. It is also true that most measurements are not easily transmitted from some remote location. Pressure measurement is an exception, but if a high pressure of.some dangerous chemical is to be indicated or recorded several hundred feet from the point of measurement, a hazard may be from the pressure or from the chemical carried. To eliminate this problem, a signal transmission system was developed. This system is usually either pneumatic or electrical. And control instruments in one location. This makes it practical for a minimum number of operators to run the plant efficiently. When a pneumatic transmission system is employed, the measurement signal is converted into pneumatic signal by the transmitter scaled from 0 to 100 percent of the measurement value. This transmitter is mounted close to the point of measurement in the process. The transmitter output-air pressure for a pneumatic transmitter-is piped to the recording or control instrument. The standard output range for a pneumatic transmitter is 20 to 100kPa, which is almost universally used. When an electronic pressure transmitter is used, the pressure is converted to electrical signal that may be current or voltage. Its standard range is from 4 to 20mA DC for current signal or from 1 to 5V DC for voltage signal. Nowadays, another type of electrical signal, which is becoming common, is the digital or discrete signal. The use of instruments and control systems based on computer or forcing increased use of this type of signal. Sometimes it is important for analysis to obtain the parameters that describe the sensor/transmitter behavior. The gain is fairly simple to obtain once the span is known. Consider an electronic pressure transmitter with a range of 0600kPa.The gain is defined as the change in output divided by the change in input. In this case, the output is electrical signal (420mA DC) and the input is process pressure (0600kPa). Thus the gain. Beside we must measure Temperature Temperature measurement is important in industrial control, as direct indications of system or product state and as indirect indications of such factors as reaction rates, energy flow, turbine efficiency, and lubricant quality. Present temperature scales have been in use for about 200 years, the earliest instruments were based on the thermal expansion of gases and liquids. Such filled systems are still employed, although many other types of instruments are available. Representative temperature sensors include: filled thermal systems, liquid-in-glass thermometers, thermocouples, resistance temperature detectors, thermostats, bimetallic devices, optical kPamAkPamAkPakPamAmAKr027 .0600160600420and radiation pyrometers and temperature-sensitive paints. Advantages of electrical systems include high accuracy and sensitivity, practicality of switching or scanning several measurements points, larger distances possible between measuring elements and controllers, replacement of components(rather than complete system), fast response, and ability to measure higher temperature. Among the electrical temperature sensors, thermocouples and resistance temperature detectors are most widely used.單片機(jī)系統(tǒng) 廣義地說，微處理系統(tǒng)是用于處理信息的，這種信息可以是電話交談，儀器讀數(shù)或企業(yè)帳戶，但是各種情況下都涉及相同的主要操作：信息處理、存儲和傳遞。在常規(guī)的電子設(shè)計(jì)中，這些操作都是以功能平臺方式組合起來的，例如計(jì)數(shù)器，無論是電子還是機(jī)械的，都要存儲當(dāng)前值，并按要求將該值增1。諸如采用計(jì)數(shù)器的電子鐘之類的任一系統(tǒng)要使其存儲和處理能力遍布整個(gè)系統(tǒng)，因?yàn)槊總€(gè)計(jì)數(shù)器都能存儲和處理一些數(shù)字。 當(dāng)前微處理化系統(tǒng)與上述的常規(guī)方法不同，它將處理，存儲和傳輸三個(gè)功能分離形成不同的系統(tǒng)單元。這種形成三個(gè)主要單元的分離方法是馮-諾依曼在20世紀(jì)40年代所設(shè)想出來的，并且是針對微計(jì)算機(jī)的設(shè)想。從此幾乎所有制成的計(jì)算機(jī)都是用這種結(jié)構(gòu)設(shè)計(jì)的，盡管包含寬廣的物理形式，從根本上來說他們均是具有相同的基本設(shè)計(jì)。 在微處理器系統(tǒng)中，處理是由微處理器本身完成的。存儲是利用存儲器電路，而進(jìn)入和出自系統(tǒng)的信息傳輸則是利用特定的輸入/輸出（I/O）電路。要在一個(gè)微處理器化時(shí)鐘中找出執(zhí)行計(jì)數(shù)功能的一個(gè)特殊硬件是不可能的，因?yàn)闀r(shí)間存儲在存儲器中，而在固定的時(shí)間間隔下由微處理器控制增值。但是，規(guī)定系統(tǒng)運(yùn)轉(zhuǎn)過程的軟件包含實(shí)現(xiàn)計(jì)數(shù)器功能的單元。由于系統(tǒng)幾乎完全由軟件所定義，所以對微處理器結(jié)構(gòu)和其輔助電路這種看起來非常抽象的處理方法使其在應(yīng)用時(shí)非常靈活。這種設(shè)計(jì)過程主要是軟件工程，而且在生產(chǎn)軟件時(shí)，就遇到產(chǎn)生于常規(guī)工程中相似的構(gòu)造和維問題。圖1.1顯示出了微型計(jì)算機(jī)中這三個(gè)單元是如何按照機(jī)器中的信息通信方式而聯(lián)接起來的。該系統(tǒng)由微處理器控制，它管理自己與存儲器和輸入/輸出單元的信息傳輸。外部的連接與工程系統(tǒng)的其余部分（即非計(jì)算機(jī)部分）有關(guān)。 盡管圖中顯示的只有一個(gè)存儲單元，實(shí)際中有RAM和ROM兩種不同的存儲器被使用。由于概念上的計(jì)算機(jī)存儲器更像一個(gè)公文柜，上述的“存儲器”一詞是非常不恰當(dāng)?shù)?；信息存放在一系列已?biāo)號的“箱子”中，而且可按問題由“箱子”的序列號進(jìn)行信息的參考定位。 微計(jì)算機(jī)常使用RAM（隨機(jī)存取存儲器），在RAM中數(shù)據(jù)可被寫入，并且在需要時(shí)可被再次讀出。這種數(shù)據(jù)能以任一