摘要：本文从总体上说明了仙桃教育“校校通”网络的需要，建设思想，设计原则，网络结构，技术方向和设备选择。-Abstract : This article from the overall picture of the Xiantao education, "School-to-School" network needs, building and design principles, the network architecture and technology direct

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