A survey of the most popular embedded systems for

Overview of embedded systems for the 21st century

1 Classification of computer industry in the past, we divided computers into large computers, medium-sized computers, small computers and microcomputers according to their architecture, computing speed, structure scale of 606.5, and applicable fields, and organized the division of disciplines and industries based on this. This classification has been followed for about 40 years. In the past 10 years, with the rapid development of computer technology, the actual situation has undergone fundamental changes. For example, the personal computer (PC), which evolved from the microcomputer defined in the late 1970s, now accounts for 90% of the global computer industry. It injects hydraulic oil into the cylinder of the actuator to drive the piston out of the market, and its processing speed also exceeds the definition of large and medium-sized computers in that year. With the wide penetration of computer technology and products into other industries, the application centered classification method has become more practical, that is, it is divided into embedded computers and general-purpose computers according to the embedded applications and non embedded applications of computers. General purpose computer has the standard form of computer. Through assembling different application software, it appears in the same face and is applied in all aspects of society. Its typical product is PC; Embedded computers are hidden in various devices, products and systems in the form of embedded systems. 2 embedded systems embedded systems are defined as: application-oriented, computer technology-based, software and hardware can be tailored to meet the strict requirements of the application system for function, reliability, cost, volume and power consumption. The number of applications of embedded computers far exceeds that of all kinds of general-purpose computers. The external devices of a general-purpose computer include embedded microprocessors. Keyboard, mouse, floppy drive, hard disk, display card, display card, card, modem, sound card, printer, scanner, digital camera, USB hub, etc. are all controlled by embedded processors. It is the application field of embedded computer in manufacturing industry, process control, communication, instruments, meters, automobiles, ships, aviation, aerospace, military equipment, consumer products and so on. Please consult 13365312612 for the specific details of the swing angle of the embedded unilateral pendulum mode and the swing angle of the zero position in the horizontal position Test speed 045 times/minute (settable), acquiescence speed: 40 times/minute system is the product of combining advanced computer technology, semiconductor technology and electronic technology with the specific applications of various industries, which determines that it must be a technology intensive, capital intensive, highly decentralized and innovative knowledge integration system. Today, the annual industrial output value brought by embedded systems has exceeded US $1trillion. The 1997 report from the embedded system conference pointed out that in the next five years, all digital TV products based on embedded computer systems alone will generate a new market of US $150billion per year in the United States. The senior manager of Ford, the king of American automobile, once declared that "Ford has sold more 'computing power' than IBM", which can imagine the scale and breadth of the embedded computer industry. At the embedded system conference held in Jose, California, USA in November, 1998, embedded Internet based on RTOS became a new technology hotspot. When the famous American futurist Negroponte visited China in January 1999, he predicted that embedded intelligent (computer) tools would be the greatest invention after PC and Internet in 4-5 years. Academician Shen Xubang, a famous embedded system expert in China, explained in detail the computer industry based on embedded chips in the next 10 years in the article "computer development and technology" published at the 11th National microcomputer academic exchange conference in Wuhan in November 1998. 3 characteristics and requirements of embedded system industry (ESI) 3.1 embedded system industry is a highly decentralized industry that cannot be monopolized. In a sense, the technology of general computer industry is monopolized. The PC industry, which accounts for 90% of the whole computer industry, 80 adopts Intel's 8x86 architecture, and the chips are basically from Intel, AMD, Cyrix and other companies. Microsoft's windows and word account for almost every computer's necessary operating system and word processor. With the operating system, it can also be combined with other applications. Therefore, the foundation of the contemporary general-purpose computer industry is considered to be an industry monopolized by Wintel (the alliance established by Microsoft and Intel in the early 1990s). Embedded system is different. It is a decentralized industry, full of competition, opportunities and innovation. No series of processors and operating systems can monopolize the whole market. Even if there is a mainstream in the architecture, different application fields determine that it is impossible for a few companies and products to monopolize the whole market. Therefore, the products and technologies in the field of embedded systems must be highly decentralized, leaving a lot of room for innovation for small and medium-sized high-tech companies in various industries. In addition, various application fields in the society are constantly developing, which requires the synchronous development of the embedded processor core, which also constitutes a powerful driving force to promote the development of embedded industry. The foundation of embedded system industry is application-centered "chip" design and application-oriented software product development. 3.2 embedded system has product characteristics. Embedded system is user-oriented, product-oriented and application-oriented. If it develops independently of the application, it will lose the market. The power consumption, volume, cost, reliability, speed, processing capacity, electromagnetic compatibility and other aspects of embedded processors are restricted by the application requirements, which are also the hot spots of competition among various semiconductor manufacturers. Unlike general-purpose computers, the hardware and software of embedded systems must be designed efficiently, tailored and redundant, and strive to achieve higher performance in the same silicon area, so as to be more competitive in the selection of processors for specific applications. The embedded processor should be tailored and added to the chip configuration according to the specific needs of users in order to achieve the desired performance; But at the same time, it is also restricted by the order quantity of users. Therefore, different processors target different users, which may be general users, industrial users or single users. Embedded system is organically combined with specific applications, and its upgrading is also synchronized with specific products. Therefore, once embedded system products enter the market, they have a long life cycle. The software in the embedded system is generally solidified in the read-only memory, rather than the disk as the carrier, and can be replaced at will. Therefore, the life cycle of the application software of the embedded system is as long as that of the embedded product. In addition, application systems in various industries