From SEGGER - Support Wiki
Jumper settings to enable trace pins
In order to enable the trace pins on this particular board jumpers JP1 and JP2 need to be in a fixed position.
- JP1: Connect PE4 to trace connector CN13 as TRACE_D1 by setting JP1 on position 1-2
- JP2: Connect PE3 to trace connector CN13 as TRACE_D0 by setting JP2 to position 1-2