【正文】 hend [1] model only 10 SCM systems are no longer only in the development and use of bare metal environment, a large number of proprietary embedded operating system is widely used in the full range of SCM. The handheld puters and cell phones as the core processing of highend microcontroller can even use a dedicated Windows and Linux operating systems.SCM is more suitable than the specific processor used in embedded systems, so it was up to the application. In fact the number of SCM is the world39。s largest puter. Modern human life used in almost every piece of electronic and mechanical products will be integrated single , telephone, calculator, home appliances, electronic toys, handheld puters and puter accessories such as a mouse with a 12 in both the Department of SCM. Personal puter will have a large number of SCM in the work. General car with more than 40 SCM, plex industrial control systems may even have hundreds of SCM in the same time work! SCM is not only far exceeds the number of PC and other puting the sum, or even more than the number of human beingsSingle chip, also known as singlechip microcontroller, it is not plete a certain logic chips, but to a puter system integrated into a to a microputer, and puter than just the lack of a microcontroller I / O devices. General talk: a chip bees a puter. Its small size, light weight, cheap, for the study, application and development of facilities provided. At the same time, learning to use the MCU is to understand the principle and structure of the puter the best choice.SCM and the puter functions internally with similar modules, such as CPU, memory, parallel bus, the same effect as well, and hard disk memory devices, and different is its performance of these ponents were relatively weak many of our home puter, but the price is low , usually not more than 10 yuan you can do with it ...... some control for a class is not very plicated electrical work is enough of. We are using automatic drum washing machine, smoke hood, VCD and so on appliances which could see its shadow! ...... It is primarily as a control section of the core ponentsIt is an online realtime control puter, controlline is that the scene is needed is a stronger antijamming ability, low cost, and this is, and offline puter (such as home PC), the main difference.Single chipMCU is through running, and can be modified. Through different procedures to achieve different functions, in particular special unique features, this is another device much effort needs to be done, some great efforts are very difficult to do. A not very plex functions if the 5039。s with the United States developed 74 series, or the 6039。s CD4000 series of these pure hardware buttoned, then the circuit must be a large PCB board! But if the United States if the 7039。s with a series of successful SCM market, the result will be a drastic change! Just because you are prepared by microputer programs can achieve high intelligence, high efficiency and high reliability!As the microcontroller on the costsensitive, so now the dominant software or the lowest level assembly language, which is the lowest level in addition to more than binary machine code language, and as so low why is the use? Many highlevel language has reached the level of visual programming Why is not it? The reason is simply that there is no home puter as a single chip CPU, not as hard as a mass storage visualization of small highlevel language program which even if only one button, will reach tens of K of size! For the home PC39。s hard drive in terms of nothing, but in terms of the MCU is not acceptable. SCM in the utilization of hardware resources to be very high for the job so although the original is still in the pilation of a lot of use. The same token, if the giant puter operating system and applications run up to get home PC, home PC, also can not afford to.Can be said that the twentieth century across the three power era, that is, the age of electricity, the electronic age and has entered into the puter age. However, this puter, usually refers to the personal puter, referred to as PC. It consists of the host, keyboard, monitor and other ponents. Another type of puter, most people do not know how. This puter is to give all kinds of intelligent machines single chip (also known as microcontroller). As the name suggests, this puter system took only a minimal integrated circuit, can be a simple operation and control. Because it is small, usually hidden in the charged mechanical stomach in. It is in the device, like the human brain plays a role, it goes wrong, the whole plant was paralyzed. Now, this microcontroller has a very broad field of use, such as smart meters, realtime industrial control, munications equipment, navigation systems, and household appliances. Once all kinds of products were using SCM, can serve to upgrade the effectiveness of products, often in the product name preceded by the adjective intelligent, such as intelligent washing machines. Now some technical personnel of factories or other amateur electronics developers to engage in out of certain products, not the circuit is too plicated, that function is too simple and can easily be copied. The reason may be stuck in the product did not use a microcontroller or other programmable logic device.SCM historySCM was born in the late 20th century, 70, experienced SCM, MCU, SOC three stages.First model the single chip microputer (Single Chip Microputer) stage, mainly seeking the best of the best single form of embedded systems architecture. Innovation model success, laying the SCM and general puter pletely different path of development. In the open road of independent development of embedded systems, Intel Corporation contributed. the microcontroller (Micro Controller Unit) stage, the main direction of technology development: expanding to meet the embedded applications, the target system requirements for the various peripheral circuits an