Stellaris LM4F120 LaunchPad Debug How To http://processors.wiki.ti.com/index.php/Stellaris_LM4F120_LaunchPad_Debug_How_To Use the following steps to use the ICDI to program and debug an off-board device. Remove the power jumper located just below the green power present indicator LED. This guarantees that the on board LM4F120H5QR is not corrupted by the debug signals. It also prevents the LM4F120H5QR from interfering with the debug signals. Connect the JTAG signals to your target processor. Connect a common ground reference between the two systems. Optionally connect the RXD and TXD pins to connect your target UART to the ICDI virtual serial port. Your ICDI is now ready to perform JTAG operations on the off board target processor.