Design Of Embedded System Based On ARM Processor

The embedded system is a special-purpose computer system that focuses on the application. It adapts to the application system which is strict in cost, reliability, power consumption, size.Since 1980s, some organizations and companies in the world have begined to research and development commercial embedded system. But the embedded system was not strong at that time, only offered some simple management functions. With the development of information technology and semiconductor technics, the prices of 32-bit microprocessor reached 8-bit one recently. Viewing whole cost of system, the price of system based on 32-bit microprocessor is lower than the one based on 8 –bit, moreover the resources of 32-bit processor are much more than 8-bit processor. Those will make 32-bit microprocessor become popular in the market gradually. System procedure are more and more complicate, thus the reliability and stability of system is difficult to be guaranteed with the traditional approach to ptogram. It is the effective way of solving this problem to use the embedded operating system as the software platform. There appear some developers of the embedded real-time operating system now days, they can offer real-time character and powerful kernel, and offer edit, emulation, compile and integrated development environment. At present, the embedded system is developing fast. As far as technology and market is concerned, the application of the embedded system will become more popular in the 21st century.The paper researchs design of embedded system based on ARM mostly. Considered from the cost, performance and power consumption, ARM microprocessor is selected in the hardware platform. Considered the stability, reliability and effective management of resource, the real-time operating system is adopted in the software platform. Operating Systems can simplify the design by dividing the application into some tasks. We finished whole construction of platform system in the method of software and hardware co-design.The paper states the design process of embedded system based on ARM through the design of the hardware platform, key code design, porting of operating system, the program of device driver.Two development boards based on ARM have been designed in the hardware platform. The design process of ARM development platform has been explained for microprocessor selection, resource distributing and unit design. It is to set up a developing platform based on ARM microprocessor. It provides hardware environment for the development of the embedded system.The design of the key code includes boot codes, interrupt procedure, Remap, procedure of FLASH download and Semihosting. The article analyzes the design process of every part code and provides the flow chart and some source codes. These codes finish the initializing of the hardware and software environment, it is the key part of designing the embedded system.In the porting of the operating system, the porting for ARM microprocessor has been realized. The article states the file structure of uC/OS-Ⅱ, register structure and operational mode of ARM7. We discuss the porting operating system by analyzing the concrete source code. The purpose that the operate system is ported is to make the real-time operate system run on ARM processor platform. It is a foundation of structuring the systems software platform. The technological difficult point of the porting operating system lies in that the developer must understand the system structure of the processor and operating system in depth.The program of serial communication driver has been finished in the design of the device driver. The article narrates the test of whole system finally. According to development trend of information industry, the development of embed system is discussed. Some suggestions are put forward on the future work.