【正文】 Can also be very plex, such as SONY intelligent machine dog, above the micro control more than on integrated motor and a variety of sensors, which can carry out various plex action and 26 feeling kind of status information. To the position of the embedded puter system was introduced. hardware layer Hardware layer contains embedded microcontroller processor, memory (SDRAM, ROM, Flash, etc), general device interface and the I/O interface (A/D and D/A, I/O, etc.). In a based on embedded processor add power supply circuit, clocking circuit and memory circuits, constitute a embedded core control module. Among them the operating system and applications can be cured in ROM. interface layer Hardware and software Layer between layers for Layer, also known as the Hardware abstraction Layer (Hardware Abstract Layer, HAL) or Board level Support Package (Board Support Package, BSP), it is half system software and upper separate underlying Hardware, the system of the ground floor of the driver has nothing to do with the Hardware, the upp。 at the same time, the embedded system software, hardware technology has been greatly improved, as puter professionals involved in embedded system application opens up a wide field. Computer professional intervention, formed in the puter application mode with puter engineering application characteristics, namely based on the embedded system software, hardware platform, work, munication of bottom embedded application. In2, two kinds of application models of coexistence and plementation Because the embedded system maximum, most widely, the bottom is the application of traditional electronic technology in the field of intelligent transformation, therefore, to understand the object of professional electronic technology team, with a minimum of embedded system software, hardware overhead, with 8machines, with a strong electronic system design color electronic system application model will be a long time continue to exist. In addition, the puter professionals will be more and more involved in the application of the embedded system, but because of the object knowledge gap, its application will focus on the work, munications, multimedia, electronic merce and so on, is not a replacement for the original electronic engineers in control, instrumentation, mechanical and electronic aspects of embedded application. Therefore, the objective 25 existence of the two kinds of application models will coexist for a long time go on, in different areas of mutual supplement. Electronic system design pattern from the puter application of design patterns in Computer Engineering, learning method and system for embedded software technology。 object system of professional technology closely related to the lack of puter engineering。t fet Intel and Philips history contribution. SCM is embedded independent development road, to the MCU stage of the development of important factors, is seeking application system on a chip to maximize resolution。 Throughput: it is in the given time the system is capable of processing the total number of events, the throughput is usually better than the average response time countdown to smaller. Real time system according to the response time can be divided into general realtime system, realtime system and realtime system three. Real time system in the design aim is to make each task to run faster, but there is no restriction on a task must be in long time, soft realtime system is more concerned on the program running results are correct, and the safety performance of system and other aspects, the task execution time required relatively more loose, the general response time can be tens of seconds or longer. General realtime system is weakly hard realtime system and realtime system is a promise, its response time can be in second order of magnitude, widely used in consumer electronic devices. Hard realtime system, each task is not only to ensure the implementation process and the validity of the results, at the same time to ensure that within a limited time to plete the task, response time is usually required in millisecond or microsecond magnitude, which relates to the medical, security, military hardware and software system is crucial. The second chapter: embedded independent development road The 1single chip microputer embedded system, create independent development road Embedded system although originated in the puter age, however, the microputer volume, price, reliability can satisfy the object system embedded application requirements, therefore, the embedded system must go independent 22 development road. This road is the road of chip. The puter on a chip, thus creating the independent development of embedded system chip era. In the exploration of MCU development way, have two kinds of pattern, namely the model and innovation mode. The pattern is essentially universal puter chip mode, it will be a general purpose puter system in the basic unit after cutting, integrated in a chip, constitute a single chip micro puter。 meet the minimum requirement of soft, hardware object configuration. And puter system of the relevant features: embedded system must be targeted to meet the requirements of system control puter system. And on two characteristics of echoes, this puter must be configured with the object system is adapted to interface circuit. In addition, in understanding the definition of embedded system and embedded devices, not be confused. Embedded equipment refers to the internal embedded system products, equipment, for example, embedded SCM appliances, instrumentation, industrial control unit, robot, mobile phone, PDA etc.. In 3, the types and development of embedded system According to the above definition of embedded system, only to meet the definition