Connect other JTAG debugger to LM3S811 Eval board

If you want to use a separate JTAG debugger, or another LM3S811 Evaluation board as the JTAG debugger for an LM3S811 Evaluation board, here's how you can do it...

Warning! after making these changes the on board USB debugger will not work!

On the eval board that you want to debug -
- Short pin 4 of U4 (RESET#) to Gnd (solder a link between R20 and the USB connector is the easiest)
- Remove R28 and R29
- Lift pins 6, 8 and 11 on U3

See the LM3S811 Evaluation Board User's Manual for component locations.

If you are using another evaluation board as the JTAG debugger then cut the wire for pin 20 in the JTAG ribbon cable and loop it back to GND on the evaluation board that you are using as a debugger (this keeps the micro on that board in reset so that it doesn't interfere with the JTAG debugger).

If you are using a third party JTAG debugger be aware that pin 20 on the JTAG connector on the eval board is connected to the micro reset, not GND as it normally is. If your JTAG debugger grounds this line you may have to disconnect it.

Why would you want to use one evaluation board to debug another, you may well ask?
Well, two reasons, one is that plugging in a different evaluation board to the same USB port doesn't always seem to work, but the main reason is that I plugged my evaluation board into the wrong power supply and put 12V on the USB port and killed the FT2232C, so I can no longer program it using the on board USB.

- Charles