【正文】 The single chip puter abbreviation Microcontroller is typical of embedded Microcontroller controller (Microcontroller Unit), mon English letters is the abbreviation of MCU said Microcontroller, it was first used in industrial control field. SCM by chip inside only CPU dedicated processor. The earliest design concept is through the huge amounts of peripheral and CPU integration in a chip, make the puter system smaller, more easy to integrate into the plex and to volume demanding control equipment of. Intelbased Z80 is the earliest designed according to this kind of thought the processor, henceforth, SCM and dedicated processor development parted. Early microcontroller is 8 bits or 4 digit. One of the most successful intelbased 8031 is simple, reliable performance, because good got a lot of praise. Then in the microputer 8031 developed MCS51 series microcontroller systems. Based on this system of SCM system have until now in widespread use. With the improvement of industrial control area requirement, begin to emerge 16bit single chip, but because the price is not ideal did not get very widely. After the 1990s with consumer electronic products development, microcontroller technology has been a tremendous increase. As the INTEL i960 series especially later ARM series widely, 32bit SCM rapidly replacing 16bit single chip of highend status, and into the mainstream market. While the traditional 8 bit microcontroller performance also obtained the rapid increase, processing power than 1980s raised hundreds times. At present, highend 32bit SCM frequency has exceeded 300MHz, performance straight after the middle of 9039。s of dedicated processor, whereas normal type exfactory price dropped to $1, the highestprofile [1] type was only ten dollars. Contemporary SCM system no longer only in LuoJi environment, development and use of special embedded operating system is widely used in the whole range of singlechip microputer. While in as a handheld puters and mobile phones key processing of highend microcontroller even can directly use the special Windows and Linux operating system. Singlechip processor more than dedicated suitable for use with embedded system, so it has gained the most applications. In fact microcontroller is the world largest number of the puter. Modern human life that are used in almost every pieces of electronic and mechanical products will be integrated have microcontroller. Mobile, telephone, calculator, home appliances, electronic toys, PDA and mouse and so on puter accessories are equipped with 12 department microcontroller. The PCS in also will affect many microputer in the work. Cars equipped with more than 40 department general singlechip microputer, plex industrial control system even there may be hundreds microputer in working at the same time! The number of MCU is not only far more than PCS and other calculation bined, and even more than the number of human beings. SCM is also called monolithic micro controller, it is not plete a logic function chips, but it is a puter system integration to a chip. The puter equivalent of a micro puter, and pared, microcontroller lack only the I/O devices. General speaking: a chip became a puter. Its pact size, light quality, cheap, for learning, application and development provides the convenience. Meanwhile, learning to use a single chip puter is knowledge of puter principle and structure of the best choice. SCM internal also use and puter functions similar module, such as CPU, memory, parallel bus and hard disk storage device functions are the same, the difference is its relative performance all these parts of our home puter weak, but the price is much lower, usually less than 10 yuan can... Use it to do some control electric appliance category is not very plicated work is sufficient. We use now roller washing machine, smoke exhaust hood, VCD and so on the home appliance inside can see the figure! ... It was mainly used as a core part of the control part. It is a kind of online realtime control puter, online is site control, need is strong antijamming ability, low cost, this also is and offline puter (such as household PC) the main difference. A single chip puter is by program running, and can be modified. Through the different program realization of different function, especially the unique some special function, this is another device needs to spend effort can do that, while some others are great effort also hard to do. One is not very plicated function if use in the United States during the 1950s development of 74 series, or from the 1960s CD4000 series these pure hardware to fix words, circuit must be a large piece of PCB board! But if if use American 1970s success on the market series microcontroller, and the results will be difference! Just because of single chip through your programming can achieve high intelligence, high efficiency and high reliability. Due to cost is sensitive microcontroller, so, at present, the dominant software or lowest assembly language, it is besides the binary machine code above the lowest language, since so lowlevel why use? Many senior language has reached the level of visual programming is why not? The reason is very simple, that is no home puter microcontroller as the CPU, also did not like hard disk that mass storage device. A visual small programs written in highlevel languages inside has even a button, also can achieve dozens of K size! For household PC hard disk speaking nothing, but the SCM speaking is unacceptable. Microputer in hardware resources utilization must high to just go, so assembly although original but still in use large. The same way, if the giant puter operating system and application software got home PC came running, household PC is also cannot bear. Can say, the twentieth century across the three electricity age, namely the age of ele