How to use an external debug probe with Nucleo board
Some ST Nucleo boards can be connected to an external debug probe like J-Link. To do this check the schematics to see if the debug signals are routed to the Extension Connectors. These can then be connected with e.g. jumper wires to the J-Link debug interface.
In case of the NUCLEO-F070RB the wiring is as follows:
|Nucleo Pin (Connector/Pin)||J-Link debug signal (Pin)|
|GND (CN7_8)||GND (4)|
|+3V3 (CN7_16)||VTref (1)|
|PA13 (CN7_13)||SWDIO (7)|
|PA14 (CN7_15)||SWCLK (9)|
|RESET (CN7_14)||RESET (15)|
To make sure the on board ST-Link does not interfere with your probe additionally disconnect the two jumpers on CN2.