Whilst working on the software for our, yet to be named network light controller, I managed to stop the Jtag from being able to connect to our LM3S6100 ARM microprocessor. All code composer would do when I pressed debug was to show me a very unhelpful dialog saying the “Frequency is out of range”.
I knew the board was okay as I had previously re-flashed it many times. Working backwards, my last change was code to control GPIO Port F. Referring to the schematic, Port F shares a pin with the TRST Line (PB7). So it seems I had accidentally overridden the TRST line and made it a GPIO, stopping the jtag from gaining control of the device, opps!
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