nRF5340 v2.0.2

Programming an external board

For boards with a standard 10-pin Serial Wire Debug (SWD) connector, or a connector that supports a standard 10-pin flat cable, it is recommended to connect to P19.

Connect the boards as shown in the following figure.

Figure 1. Connecting an external board to P19
Connecting a custom board to P19
It is recommended to power the external board separately from the DK. The voltage on the external board must match that of the DK. When the DK is powered through the USB connector, the voltage is 3V.

When pin 3 (SWD0_SELECT) of P19 is connected to GND through the 10-pin flat cable, the interface MCU programs or debugs the target chip on the external board instead of the onboard nRF5340 System on Chip (SoC).

If it is inconvenient to have a separate power supply on the external board, the nRF5340 DK can supply power through the Debug out connector P19. To enable this, short solder bridge SB47.
To avoid damaging your board, do not connect a separate power supply to the external board when SB47 is shorted.
To avoid overloading the power supply and damaging the DK, use VDD and keep the supply below 100 mA. Do not use a Lithium-polymer (Li-Poly) source.
The following section includes an illustration of the P19 connector pinout with a description table.
Figure 2. Debug output connector P19
Debug output connectors P19 nRF5340 DK
Table 1. Connector P19 pinout for programming external targets
Pin number Signal Description
1 SWD0_VTG Optional voltage supply to the external target
2 SWD0_SWDIO SWD Data Input/Output
3 SWD0_SELECT Debug out select signal, connect to ground on external board
4 SWD0_SWDCLK Serial Wire Clock line
5 GND Ground
6 SWD0_SW0 The Serial Wire Output (SWO) line is not used for programming and debugging over SWD
7 N.C. Not used
8 N.C. Not used
9 N.C. Not used
10 SWD0_RESET Reset line