【導讀】近年來隨著計算機在社會領域的滲透，單片機的應用正在不斷地走向深入，同時帶動了傳統(tǒng)控制檢測的更新。單片機往往是作為一個核心部件來使用。僅單片機方面知識是不夠的，還應根據(jù)。具體硬件結(jié)構(gòu)，以及針對具體應用對象特點的軟件結(jié)合，以作完善。以在工業(yè)控制和生活中有大量的應用，就在于它有獨特的定時、計數(shù)功能。作和生活中，到處都是用著定時器，例如各種定時開關(guān)，各種家電。單片機的專用定時器就是一種很好的選擇。它具有很高的性價比。本設計主要包含模塊為基本的單片機系統(tǒng)、定時中斷模塊、外。圍電路、外部按鍵輸出模塊、數(shù)碼管LED顯示模塊。時間T1、T2、T3。所有數(shù)字時間可調(diào)。

　　

【正文】 pecially very good is suitable from benefits from on its processing speed and the enhancement piece the periphery function collection, such as: The automobile power control, the vehicles dynamic are hanging, lock on the other side apply the brake with the stable control application. As a result of these decisive applications, the market requirement one kind reliable has lowly disturbs the expense potency controller which the ambush responds, the service massive time and the event actuates the integrated periphery ability which needs in the realtime application, has outdoes the average processing power in the sole routine package the central processor. Has the equipment economy and the legal risk which the operation cannot be forecast are very high. Once enters the market, especially the duty decisiveness application such as autopilot or locks on the other side the braking system, will be wrong will be in the financial resource forbids. The redesign expense may reach as high as 500K US dollar. The single slice machine is also called tiny controller, is because it was used in the industry to control realm at the earliest stage. Single slice machine from inside chip have CPU appropriation processor to develop only since then. At the earliest stage of design the principle is to pass to integrate a great deal of peripherals and CPU in a chip, making calculator system smaller, integrating more easily into plicated of but to mention to request a strict control equipments in the middle. The INTEL Z80 is the processor which designed according to this kind of thought at the earliest stage, from now on, single slice the development of the machine and appropriation processor went by different roads then. The single slice of the earlier period all of machines are 8 or them, the INTEL is most successful of 8031, because of in brief dependable but the function was quite good to acquire very big good opinion. Henceforth at 8031 up developed MCS51 series a 河南科技大學本科畢業(yè)設計（論文）34single slice machine system. According to the single slice of this system machine system is still in the extensive usage till now. Because the industry controls the exaltation of[with] realm request, starting appearing 16 single slice machine, but because sex price wanted to don39。t get a very extensive application than the disregard. Develop greatly along with the consumption electronics product after 9039。s, the single slice machine technique got a huge exaltation. Along with the extensive application of INTEL i 960 series especially later ARM series, the 32 single slice machine replaces 16 single slice the high level position of the machine quickly, and gets into an essential market. And traditional of 8 single slice the function of the machine also got to fly to raise soon, handling an ability to pare with to raise few a hundred folds in 8039。, 32 single slice of the high level with main machine already over 300 MHz, the function keeps appropriation processor of making track for the mid 9039。s, and the mon model number factory price drop into to USD 1, tallest carry of model number also only USD contemporary and single slice machine system has already no longer developed and used just under the naked machine environment, the in great quantities appropriative builtin operate system is applied extensively in the whole series of the single slice is on board. But Be the high level of handheld PC and cellular phone core processing single slice the machine even can use appropriative Windows and the Linux operate system directly. Single slice the machine ratio appropriation processor is the most suitable to match to apply in the builtin system, so it got the most applications. In fact the single slice machine is an amount the most calculators are in the world. The modern mankind are living medium use of assemble in almost each electronics and machine product have a single slice machine. All have 12 single slice machine in the puter access ories such as cellular phone, telephone, calculator, home appliances, electronics toy, handheld PC and mouse etc.. And personal puter in would also capable number not a few single slice the machine be working. Provide with more than 40 departments a single slice machine generally on the car, plicated industry39。s controlling the top of the system even may has single several hundred pedestals slices machine to work in the meantime! Single slice the amount of the machine not only far above the PC machine and other calculations of prehensive, even than the mankind39。s amount still want have another.DescriptionThe AT89C51 is a lowpower, highperformance CMOS 8bit microputer with 4K bytes of 河南科技大學本科畢業(yè)設計（論文）35Flash programmable and erasable read only memory (PEROM). The device is manufactured using Atmel’s highdensity nonvolatile memory technology and is patible with the industrystandard MCS51 instruction set and pin out. The onchip Flash allows the program memory to be reprogrammed insystem or by a conventional nonvolatile memory programmer. By bining a versatile 8bit CPU with Flash on a monolithic chip, the Atmel AT89C51 is a powerful microputer which provides a highlyflexible and costeffective solution to many embedded control applications.Function characteristicThe AT89C51 provides the following standard features: 4K bytes of Flash, 128 bytes of RAM, 32 I/O lines, two 16bit timer/counters, a five vector twolevel interrupt architecture, a full duplex serial port, onchip oscillator and clock circuitry. In addition, the AT89C51 is designed with static logic for operation down to zero frequency and supports two software selectable power saving modes. The Idle Mode stops the CPU while allowing the RAM, timer/counters, serial port and interrupt system to continue functioning. The Powerdown Mode saves the RAM contents but freezes the oscillator disabling all other chip functions until the next