Research And Implementation Of The Arm Debug System

With the development of microelectronic technology and computer technology, the functions of micro-controller chips is becoming more powerful, and the equipment as well as systems embedded micro-controller chips is becoming more and more.,which lead the the widely use of embedded systems technology. The embedded system has been extensively infiltrated into every aspect of people's daily lives. Because of the diversity and complexity of the embedded system, the developers face new challenges. The debug state is a very important part of the development process. The embedded system requires to do cross-debugging during the development. The debugger becomes an important measure to the embedded system. On the one hand, the complexity of embedded systems is continuously improved and the difficulty of debugging is improving. At the same time the continuous development of the SOC, FPGA technology inject new vitality to the development of debugging technology, and on the other hand the methods or tools to develop embedded system is so diversiform which bring great flexibility to the debugging work.The article first decribes the characterstics of embedded system and features of embedded system's debug. The paper analyzes the principles of the main methods for the ARM debugging during its development, and the principles of the main technology; also concludes the advantages and disadvantages of various methods as well as the appropriate application through the contrasts. The design of system called MiniJtag that the paper brings forward is the fusion of two mainstream debugging methods, and based on the results of the contrasts of the two mainstream debugging methods.The paper involves in the main technologies used during the realization process: GDB debugger structure and realization process, the details of RSP protocol as well as JTAG debug standards and the debugging framework of ARM. According to the MiniJtag debugging systems of which the author involved in the development, and based on ARM920T and GDB debugger tools, the paper raises a low-cost simple debugging method. The paper describes the structure and levels of the MiniJtag debugging system; analysises of the linkages between various levels and debugging order abstraction layer and the layer of parallel read-write whose development I am responsible for;as well as introduces the methods of reading and writing on the target board registers, system storage space and set or clear breakpoints, and other commonly used means of debugging. The thinking of designing MiniJtag debugging system is innovative . Compared to the commercial toll MiniJtag has the low-cost advantage. So it fits some of the developers or learners who pay more concern on the cost than the efficiency. And the design of the system has paid great zttention to the expansion and maintainability of the system, which manifests mainly in the flexibility of the debugging tool, support for different version of ARM processor, as well as the flexibility of the system that can be optimized easily.