文章主要介绍ARM JTAG调试的基本原理。基本的内容包括了TAP (TEST ACCESS PORT) 和BOUNDARY-SCAN ARCHITECTURE的介绍，在此基础上，结合ARM7TDMI详细介绍了的JTAG调试原理。-article introduces ARM JTAG Debugging the basic principles. The basic content including TAP (TEST PORT ACCESS) and BOUNDARY - SCA N AR