In recent years, with the rapid development of computer technology, communication technology, the rapid development of information technology, and the extensive Internet
Application, traditional control disciplines are changing, and there are many new growth points. One phenomenon accompanying is control
Professional considerable students have entered the computer and communications industry after graduation, and some people talk about the control, automatic
The professional can be canceled. The emergence of these situations allows us to control educators repeatedly, and how the traditional control should
Broaden the field of it? What should I teach what should be used to make students feel useful?
In recent years, we use the latest technology in the information industry in the research and development of embedded systems and their applications.
The boundaries between the disciplines, the way is controlled by the road, although it is challenging everywhere. "Control" we are familiar with
There is a lot of limitations. One is not considered hardware restrictions, the second is to consider the complexity and computational power of the controller, the third is
Do not pay attention to practicality and efficiency. In the case of microprocessor, microphone, and micro-executive elements continue to introduce new products.
The idea and means of control are experiencing huge changes. After a hard practice, we have the control school.
The research and teaching of the department have some new awareness. This textbook is summarized on the basis of our annual research work.
It is still rough, and it is also necessary to spend the future to improve and improve it. Now take it as a trial textbook
Reference, I hope to make our new contribution to the update of discipline teaching content.
Definition of embedded system
The embedded system refers to a dedicated computer system for performing a separate function. It consists of a microprocessor, a timer,
A series of microelectronic chips such as microcontrollers, memory, sensors, and devices, and micro operations embedded in memory
System, control application software, together to achieve various real-time control, monitoring, management, mobile computing, data processing, etc.
Automated processing task. Embedded systems are used centered, microelectronic technology, control technology, computer technology and
Based on communication technology, emphasize the synergy and integration of hardware software, software and hardware can be cut to meet systemalism
Energy, cost, volume, and power consumption.
The simplest embedded system only has the ability to perform a single function, only single work in the unique ROM
Energy control program, no micro operating system. Complex embedded system, such as personal digital assistant (PDA), hand-held
Brain (HPC), etc., has almost the same function as the PC. The difference from the PC is simply to the PC.
Software is embedded in the ROM, RAM, and / or FLASH memory instead of being stored in a carrier such as a disk. A lot of complex
The embedded system is composed of several small embedded systems.
Hardware / software feature of embedded systems
The hardware of the embedded system must be based on the specific application tasks, power consumption, cost, volume, reliability, processing power, etc.
Select to an indicator. The core of the embedded system is system software and application software. Due to limited storage space,
The software code is compact, reliable, and most of the real-time requirements are strict.
Early embedded system design methods are usually adopted "hardware priority" principles. That is, only rough estimation software
In the case of a matter of service, the hardware design and implementation are first performed. Then, on this hardware platform, software design is performed.
It is therefore difficult to achieve the effect of making the best use of hardware software resources. At the same time, once it is found when testing
The entire design process will be re-performed when the design is modified.
This traditional design method can only improve the respective performance of hardware / software, and it is impossible to make the system in a limited design space.
Good performance integrated optimization depends to largely depends on designers' experience and repetitive experiments.
With the increasing powerful and miniaturization of electronic system functions, problems involved in system design have become more and more
More, the difficulty is getting bigger and bigger. At the same time, hardware and software are no longer a four concepts that are completely separated, but closely combined, interacting. Thus, a hardware and hardware collaboration (CODESign) design method, that is, the unified method and tools are soft
Collaborative design of software and hardware architecture to minimize system software and hardware capabilities, avoid
Various disadvantages from the Software and Hardware Architecture are designed to obtain high performance low cost optimization design.
Embedded operating system
The current popular embedded operating system can be divided into two categories: one is from the operating system running on a personal computer
Transplantation to the embedded system, the embedded operating system, such as Microsoft's Windows CE and its new version,
Sun's Java operating system, Langxun Technology company's Inferno, embedded Linux, etc. This type of system passes through
Long-term operational tests such as computer or high-performance computers, technology is increasingly mature, related standards and software development
The way has been widely accepted by users, while accumulating rich development tools and application resources.
Another type is a real-time operating system, such as Windriver's VxWorks, ISI's PSOS, QNX System Software
The company's QNX, ATI's Nucleus, Chinese Academy of Sciences Kesi Group's Hopen embedded operating system, etc.
Products in the structure and implementation of the operating system, the real-time high reliability, etc.
Design, and provide independent and complete system development and test tools, more use in military products and industrial controls
In the field of system.
Linux is an open source operating system that has been gradually mature since the 1990s. Linux version on the PC
Under the development of millions of enthusiasts in the world, it has been developed very rapidly. UCLinux at the end of the 1990s,
RTLinux, etc., have been launched in the embedded area, which has a large number of programmers and ready-made
Using procedures, it is a valuable resource for our research and development.
Learning the meaning of embedded system
In terms of control, the embedded system relates to the underlying, chip-level information processing and control. In some way
In the sense, the understanding and driving of these "micro" world is the true purpose of control. Embedded system and usual meaning
The control system has many differences in design ideas and overall architectures, and these differences are traditional control.
There are less teaching students in the teaching teaching. In today's information society, embedded systems are in people's daily work and students.
The share of living may have exceeded the traditional control system, which is why our students feel that
Useful, and useful without learning. There are still many problems in embedded systems and development environments.
Among the research development, such as the hardware software of the embedded system collaborative design; multi-objective, multitasking microencale
Embedded operating system; real-time problem, distributed computing, distributed information interaction and integrated office
The multi-objective cross-compilation and cross-debugging tools of the embedded system, etc. We hope to pass this textbook
With our experimental development platform, learn some basic theories of embedded systems and the comprehensive design of hardware software
With skills, personally, implement a solution of embedded systems, lay a preliminary base for future research
foundation.
"Embedded System" is a comprehensive combination of one theory and actual close combination of automation disciplines, knowledge and technical content.
Complex professional courses will gradually mature with the development of the information industry.
