Research And Implementation Of Debugging Tools Based On Boundary-Scan Technology

Because the application and complexity of embedded system have increased more and more, the debug of embedded system has become an indispensable aid during the development. Am embedded system based on ARM is with on-chip debugging functionality supported JTAG debug, and ARM core has embedded an on-chip emulator component named EmbeddedICE-RT which can enforce the debugging capabilities. Therefore, for am embedded system based on ARM, we can design and implement debugging tools, and build a debugging system.According to the JTAG technology and ARM debug theory, several debug methods have been compared, then the design of our debugging tools is given. Firstly, a soft debugger named Debugger needs to design and implement. There are two JTAG drivers of Debugger. One is general JTAG driver, and the other one is RDI JTAG driver. Secondly, an easy and cheap but utility JTAG emulator needs to design and implement. The JTAG emulator is similar to emulator of Wigger, and it converts the parallel's signal to JTAG signal. Finally, Debugger controls the target by JTAG emulator, and debugging purpose has achieved.The JTAG driver is the core support of the Debugger's debugging function. The general JTAG driver is designed by us without using other standard debugging protocol. And it has implemented three functions, including support of different ARM, operation of FLASH and soft simulation of JTAG sequence. But the RDI JTAG driver is implemented on the basis of RDI standard and referred to the implementation general JTAG driver. And it can use solely by other soft debugger who is accord to RDI standard interface as a debugging agent. In order to supply a uniform interface to the command interpreter of Debugger, some interface functions that are the same with two JTAG drivers have been designed, and they implement transparency for super stratum.Finally, the debugging tools that we design and implement have been tested and evaluated. Tests show that the debugging tools have certain feasibility and practicality.