本标准定义了对IEEE Std 1149.1（TM）的扩展，以标准化边界扫描结构和方法，以帮助确保对高级数字网络进行简单、可靠且侵入性最小的边界扫描测试。现有标准没有充分解决此类网络问题，尤其是对于交流耦合、差分或两者兼有的网络。本标准启用的测试将与IEEE Std 1149.1常规数字网络测试并行运行，并与IEEE Std 1149一起运行。 4（TM）传统模拟网络的测试。本标准还规定了IEEE Std 1149.1的软件和边界扫描描述语言（BSDL）扩展，这些扩展是支持新的I/O测试结构所必需的。

This standard defines extensions to IEEE Std 1149.1(TM) to standardize the boundary-scan structures and methods required to help ensure simple, robust, and minimally intrusive boundary-scan testing of advanced digital networks. Such networks are not adequately addressed by existing standards, especially for those networks that are ac-coupled, differential, or both. Testing enabled by this standard will operate in parallel with IEEE Std 1149.1 testing of conventional digital networks and in conjunction with IEEE Std 1149.4(TM) testing of conventional analog networks. This standard also specifies software and Boundary-Scan Description Language (BSDL) extensions to IEEE Std 1149.1, which are required to support new I/O test structures.