When working with the XPC56XX EVB motherboard + a processor mini-module, the debug and trace signals have more than one end point: The JTAG connector, the trace connector and the pin array on the motherboard. The end points are unterminated and can cause signal reflections which disturb debugging. Especially the branch line of TCK to the EVB motherboard can cause problems.

If the debugger fails to connect (configuration error or debug port fail), we recommend disconnecting the signal path to the motherboard, or at least terminate TCK at the XPC56XX EVB motherboard's pin array with a 220~470 Ohm resistor to GND.