The primary debug interface on the nRF9161 DK is the Segger OB debugger available through the Universal Serial Bus (USB) port. If a power supply other than USB is used on the Development Kit (DK), this functionality is disabled.
The Debug in connector P18 makes it possible to connect external debuggers for debugging when the interface USB cable is not connected or if the DK is in IF MCU DISCONNECT mode.
Figure 1. Debug input connector and trace footprint
To utilize the SW trace feature on nRF9161, a footprint for a 20-pin connector (P25) is available. If trace functionality is required, a 2×10 pin 1.27 mm pitch surface mount connector can be mounted. nRF9161 General-Purpose Input/Output (GPIO)s used for the trace interface are not available for application firmware use during trace.
| GPIO | Trace |
|---|---|
| P0.21 | TRACECLK |
| P0.22 | TRACEDATA[0] |
| P0.23 | TRACEDATA[1] |
| P0.24 | TRACEDATA[2] |
| P0.25 | TRACEDATA[3] |