【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)。盡管他的大部分功能。內(nèi)存、內(nèi)部和外部總線系統(tǒng)，目前大部分還會(huì)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。而現(xiàn)在最強(qiáng)大的單片機(jī)系統(tǒng)甚至可以將聲音、圖。單片機(jī)由芯片內(nèi)僅有CPU的專用處理器發(fā)展而來(lái)。進(jìn)復(fù)雜的而對(duì)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)出的處理器，從此以后，單片機(jī)和專用處理器的發(fā)展便分道揚(yáng)鑣。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?jiǎn)。單可靠而性能不錯(cuò)獲得了很大的好評(píng)?；谶@一系統(tǒng)的單片機(jī)系統(tǒng)直到現(xiàn)在還在廣泛使用。代16位單片機(jī)的高端地位，并且進(jìn)入主流市場(chǎng)。出廠價(jià)格跌落至1美元，最高端的型號(hào)也只有10美元。而在作為掌上電腦和手機(jī)核心處理的高端單片機(jī)甚至可以直接使用。單片機(jī)的數(shù)量不僅遠(yuǎn)超過(guò)PC機(jī)和其他計(jì)。就是單片機(jī)沒(méi)有家用計(jì)算機(jī)那樣的CPU，也沒(méi)有像硬盤那樣的海量存儲(chǔ)設(shè)備。

　　

【正文】 sehold appliances It can be said that almost all home appliances are using the singlechip control, electric rice from favorable, washing machines, refrigerators, air conditioners, color TV and other audio video equipment, and then to the electronic weighing equipment, all kinds, everywhere. 4. On puter works and munication applications in the field of Generally with the modern singlechip munication interface, can be easily carried out with puter data munications, puter works and in interapplication munications equipment to provide an excellent material conditions, the munications equipment is now basically a singlechip 14 Intelligent Control, from the mobile phone, telephone, miniprogramcontrolled switchboards, building automated munications system call, the train wireless munications, and then you can see daytoday work of mobile phones, Mobile munications, such as radios. 5. Singlechip in the field of medical equipment applications Singlechip microputer in medical devices have a wide range of purposes, such as medical ventilator, various analyzers, monitors, ultrasonic diagnostic equipment and hospital call systems. 6. In a variety of largescale electrical applications of modular Some special singlechip design to achieve a specific function to carry out a variety of modular circuit applications, without requiring users to understand its internal structure. Integrated singlechip microputer such as music, which seems to be simple functions, a miniature electronic chip in a pure (as distinct from the principle of tape machine), would require a plex similar to the principle of the puter. Such as: music signal to digital form stored in memory (similar to ROM), read out by the microcontroller into analog music signal (similar to the sound card). In large circuits, modular applications that greatly reduces the size, simplifying the circuit and reduce the damage, error rate, but also to facilitate the replacement. In addition, singlechip microputer in the industrial, mercial, financial, scientific research, education, defense aerospace and other fields have a wide range of uses. chip explains The AT89C52 is a lowpower, highperformance CMOS 8bit microputer with 8 Kbytes of Flash programmable and erasable read only memory (PEROM). The device is manufactured using Atmel’s high density nonvolatile memory technology and is patible with the industry standard 80C51 and 80C52 15 instruction set and pinot. The onchip Flash allows theprogram memory to be reprogrammed insystem or by a conventional onvolatile memory programmer. By bining a versatile 8bit CPU with Flash on a monolithic chip, the Atmel AT89C52 is a powerful microputer, which provides a highly flexible and cost effective solution to many embedded control applications. Eatures： 8 Kbytes of InSystem Reprogrammable Flash Memory。 Endurance:1000 Write/Erase Cycles 256 8Bit Internal RAM Three 16Bit Timer/Counters Eight Interrupt Sources Three Description The AT89C52 is a lowpower, highperformance CMOS 8bit microputer with 8 Kbytes of Flash programmable and erasable read only memory (PEROM). The device is manufactured using Atmel’s high density nonvolatile memory technology and is patible with the industry standard 80C51 and 80C52 instruction set and pinot. The onchip Flash allows the program memory to be reprogrammed insystem or by a conventional onvolatile memory programmer. By bining a versatile 8bit CPU with Flash on a monolithic chip, the Atmel AT89C52 is a powerful microputer, 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 twolevel interrupt architecture, a full duplex serial port, onchip oscillator, and clock circuitry. In addition, the AT89C52 is designed with static 16 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 Power Down Mode saves the RAM contents but freezes the oscillator, disabling all other chip functions until the next hardware reset. AT89C52 40 pins, 32 external bidirectional input / output (I / O) ports, and includes two 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 methods, also available online programming. The generic microprocessor and Flash memory together, particularly when repeated erase the Flash memory can effectively reduce the development costs.