【正文】 Self Programmable Flash on a monolithic chip, the Atmel ATmega8 is a powerful microcon troller that provides a highlyflexible and costeffective solution to many embedded control applications. The ATmega8 AVR is supported with a full suite of program and system development tools, including C pilers, macro assemblers, program debugger/simulators, InCir cuit Emulators, and evaluation kits. MCU application Currently microcontroller perated into every aspect of our lives, almost hard to find which field no trace of single chip. Missile navigation devices, the plane on various kinds of instrument control, puter work munication and data transmission, industrial automation process realtime control and data processing, is widely used in all kinds of intelligent IC card, civil luxury car security system, video camera, video camera, fullautomatic washing machine control, as well as programcontrolled toys, electronic pets, etc, these are inseparable from microcontroller. Mention automatic control field of robot, intelligent instruments, medical equipment and various kinds of intelligent machinery. Therefore, SCM39。 , energy feedback unit applies to need to stop quickly of occasions, such as rolling mill, large longmen planer, spindle etc, , energy feedback unit work may apply to other motors in renewable power state occasions. Four, energy feedback element and braking unit difference Energy feedback unit is renewable power of electric motor to power grid (right now meter feedback inversion), supply other equipment use, feedback efficiency can reaches as high as 97% above. And braking unit needs and braking resistance are used together, motor power generation of electricity consumption in regenerative braking resistance into heat wasted. In addition, using braking unit and braking resistance of braking unit, pared with energy feedback braking torque is small, can39。 POP 39。0000 39。 but (user) 39。and39。 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。0 39。should not39。s ROM must exist in the39。and39。 , energy feedback unit suitable to the large inertia load such as: fan, cement system pipe, dynamic balancing machines, centrifuge, etc。s study, development and application of puter application will create and intelligent control of scientists and engineers. SCM is widely applied in instrumentation, household appliance, medical equipment, aerospace, special equipment of intelligent management and process control and other fields, roughly can divide the following several categories: 1. In intelligent instruments on the application Singlechip microputer with small size, low power consumption, control function is strong, flexible, miniaturization and extended use convenience etc, which are widely used in instrumentation, bined with different kinds of sensors, which can realize such as voltage, power, frequency, humidity, temperature and flow rate, speed, thickness, Angle, length, hardness, elements and pressures, physical measurement. Adopting SCM control makes instrument digital, intelligent, miniaturization, and functional than by electronic or digital circuit stronger. For example precision measuring equipment (power meter, oscilloscope, various analyzer). 2. The application in industrial control MCU can constitute the various forms of control system, the data acquisition system. For example the production line of the intelligent pipe principle, the elevator intelligent control, various alarm system, work with puter constitute a secondary control system, etc. 3. The application in household appliances It can be said that now of household appliances basically adopts singlechip microputer control, from electric cooker, washing machines, refrigerators, air conditioner, color television, other audio video equipment, arrive again microelectronic quantity equipment, multifarious, omnipresent. 4. In puter work and munication in the field of application Modern singlechip generally have munication interface can be easily and puter data munications, for in the puter work and munication between devices applied to provide the excellent material conditions of present munication equipment basically realized the singlechip microputer intelligent control, from mobile, telephone, small pab