The debug hub is a piece of intellectual property that enables multiple clients, or "nodes" to share the JTAG BST architecture provided in APEX^™ 20K, ARM^®-based Excalibur^™, Cyclone^™, Mercury^™, Stratix^™, and Stratix^™ GX devices. Currently, the debug hub supports only nodes from the SignalTap^® II Logic Analyzer.