说明：  这篇文章主要介绍 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。
(This article introduces the basic principles of ARM JTAG debug. The basic elements include TAP (TEST ACCESS PORT) and BOUNDARY-SCAN ARCHITECTURE introduction, in this based on the combination described in detail in the ARM7TDMI JTAG debugging principles.)