【導(dǎo)讀】單片機(jī)是指一個(gè)集成在一塊芯片上的完整計(jì)算機(jī)系統(tǒng)。統(tǒng)，目前大部分還會具有外存。同時(shí)集成諸如通訊接口、定時(shí)器，實(shí)時(shí)時(shí)鐘等外圍設(shè)備。片機(jī)，它最早是被用在工業(yè)控制領(lǐng)域。單片機(jī)由芯片內(nèi)僅有CPU的專用處理器發(fā)展而來。集成進(jìn)復(fù)雜的而對體積要求嚴(yán)格的控制設(shè)備當(dāng)中。INTEL的Z80是最早按照這種思想設(shè)計(jì)出。早期的單片機(jī)都是8位或4位的。其中最成功的是INTEL的8031，因?yàn)楹唵慰煽慷阅?。不錯(cuò)獲得了很大的好評。片機(jī)系統(tǒng)直到現(xiàn)在還在廣泛使用。但因?yàn)樾詢r(jià)比不理想并未得到很廣泛的應(yīng)用。術(shù)得到了巨大提高。隨著INTELi960系列特別是后來的ARM系列的廣泛應(yīng)用，32位單片機(jī)。迅速取代16位單片機(jī)的高端地位，并且進(jìn)入主流市場。目前，高端的32位單片機(jī)主頻已經(jīng)超過。而在作為掌上電腦和手機(jī)核心處理的高端單。超過PC機(jī)和其他計(jì)算的總和，甚至比人類的數(shù)量還要多。它主要是作為控制部分的核心部件。因此，當(dāng)我們回顧嵌入式系統(tǒng)發(fā)展道路時(shí)，不要忘記Intel和P

　　

【正文】 MCU from mobile phone, telephone, miniprogramcontrolled switchboards, building automated munications call system, train radio munication, to the daily work can be seen everywhere in the mobile phones, trunked mobile radio, walkietalkies, etc.. （ 5） Microputer in the field of medical device applications MCU in the use of medical devices is also quite extensive, such as medical respirator, the various analyzers, monitors, ultrasound diagnostic equipment and 10 hospital beds, etc. call system. （ 6） In a variety of major appliances in the modular applications Designed to achieve some special single specific function to be modular in a variety of circuit applications, without requiring the use of personnel to understand its internal structure. If music integrated single chip, seemingly simple function, miniature electronic chip in the (the principle is different from the tape machine), you need a puter similar to the principle of the plex. Such as: music signal to digital form stored in memory (like ROM), read by the microcontroller, analog music into electrical signals (similar to the sound card). In large circuits, modular applications that greatly reduce the volume, simplifies the circuit and reduce the damage, error rate, but also easy to replace. （ 7） Microcontroller in the application field of automotive equipment SCM in automotive electronics is widely used, such as a vehicle engine controller, CAN busbased Intelligent Electronic Control Engine, GPS navigation system, abs antilock braking system, brake system, etc.. In addition, the MCU in business, finance, research, education, national defense, aerospace and other fields has a very wide range of applications. chip explains The AT89C52 is a lowpower,highperformance CMOS 8bit microputer w ith 8 K bytes of Flash programmable and erasable read only memory(PEROM).The devic e is manufactured using Atmel39。s high density nonvolatile memory technology and is patible w ith the industry standard 80C51 and 80C52 instruction set and onc hip Flash allows the program memory to be reprogrammed insystem or by a conbventional onwolatile memory bining a versatile 8bit CPU w ith Flash on a monolithic chip,the Atmel AT89C52 is a pow erful microc omputer,which provides a highly flexible and cost effec tive solution to many embedded c ontrol applic ations. Eatures: 8 K bytes of Insystem Reprogrammable Flash Memory。Endurance:1000 Write/Erase Cycles 2568 bit Internal RAM 32 Programmable I/O Lines Three 16Bit Timer/Counters Eight Interrupt Sources Programmable Serial Channel Low Pow er Idle and Power Down Modes ThreeLevel Program Memory Lock Fully Static Operation:0 Hz to 24 MHz Desc ription The AT89C52 is a low power,highperformance COMS 8bit microputer 11 w ith 8K bytes of Flash programmable and erasable read only memory(PEROM).The devic e is manufactured using Atmel39。s high density nonvolatile memory technology and is c ompatible w ith the industry standard 80C51 and 80C52 instruction set and on chip Flash allows the program memory to be reprogrammed insystem or by a conventional onvolatile memory bining a versatile 8bit CPU w ith Flash on a monolithic chip,the Atmel AT89C52 is a powerful microc omputer,which provides a highly flexible and cost effective solution to many embedded control applications The AT89C52 provides the following standard features: 8k bytes of Flash ,256 bytes of RAM,32 I/O lines,three 16bit timer/counters,a sixvector tw olevel interrupt architecture , a full duplex serial port,onchip osc illator,and c loc k c ircuitry . In addition, the AT89C52 is designed with static logic of operation down to zero frequenc y and supports two softw are selectable power saving modes. The Idle Mode stops the CPU while allow ing the RAM,timer/c ounter,serial port,and interrupt system to continue functioning. The Power Dow n Mode saves the RAM contents but freezes the osc illator,disabling all other chip func tions until the next hardware rest. AT89C52 40 pins, 32 external bidirectional input/output(I/O)ports, and inc ludes tw o external interrupt ports, three 16bit programmable timer counters, two full duplex serial port, 2 a readwrite port line,AT89C52 can be programmed according to conventional method, also available online programming. The generic microprocessor and Flash memory together, partic ularly w hen repeated erase the Flash memory c an effectively reduce the development c osts.