This article gives a practical, high-signal overview of JTAG and SWD debugging techniques—from wiring and level shifting to breakpoints, trace, scripting with OpenOCD/pyOCD, and design tips that make production and service smoother. To enable debugging of the Ethernet management port, use the debug fastethernet command in EXEC mode. If your pcb design will ship in volume, the details below will pay. JTAG (named after the Joint Test Action Group which codified it) is an industry standard for verifying designs of and testing printed circuit boards after manufacture. JTAG implements standards for on-chip instrumentation in electronic design automation (EDA) as a complementary tool to digital. OpenOCD is a powerful tool for On-Chip Debugging of ARM, MIPS, and some other architectures. The appropriate configuration file (make this a link to the file) should look like: To use it with openocd: Boundary scan can be used to take control of a device to set I/O pin state (EXTEST), or to view. JTAG/Boundary-Scan Technology for PCB Testing and In-System Configuration is an essential technique widely used in the production of electronic assemblies in the 21st century.
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