NRF51822 WLCSP NRF51DK programming

[kcyte]

Does the NRF51 DK come with a SWD interface connector-cable to plug into a PCB's SWD port when flashing/programming code into a WLCSP chip soldered onto the PCB? If not, are there any recommendations on which cable to use?

[Kenneth]

Hi,

There is no cable included I believe. So typically you just use some breadboard wires you may have, or you can buy in-circuit programming adaptor from Tag-Connect if you make the footprint for it on the target PCB.

Best regards,
Kenneth

[kcyte]

Hi but I thought the NRF51822 only supports flashing/programming through SWD interface? It doesn't look like the Tag-Connect adaptor has SWD pins

[Kenneth]

I might have linked the wrong cable, try this: http://www.tag-connect.com/JLINK 

Kenneth

[kcyte]

So if I am correct, to program from the nRF51 DK board I need a cable/adapter that can plug into the 10 pins of the 'P18 Debug In' debug header in the nRF51 DK. I would then need to design my PCB to have the interface for the other end of the cable to plug into. 

Another question: If I am using a Segger J Link external debugger device (which has 20 pin port for target), do I still need a 10 pin (2x5) SWD adapter or can I just use the included 20-pin (2 x 10) JTAG connector cable to connect the J Link to my PCB? 

Does the NRF51822 WLCSP chip only accept a 10 pin SWD  programming connector?

[Kenneth]

Hi,

This is much simpler than you think.

You just need to connect 4 pins in total, that is VTarget (=VDD), SWDIO, SWDCLK, and GND. How you physically connect these 4 pins from the j-link header, for instance using 4 single breadboard wires, 4 vero wires, or a more professional cable from tag-connect is entirely up to you.

Where the 4 pins are located depends on the actual programmer you are using, you can refer to the documentation for the nRF52-DK or SEGGER j-link, but typically they follow this pin out for historically reason:

https://www.segger.com/products/debug-probes/j-link/accessories/adapters/9-pin-cortex-m-adapter/ 

Note that if you are using our nRF52-DK to program external board, you should also connect GND_DETECT to the target board, since that is require to detect that the DK should program a third party board and not the on-board nRF52832.

Best regards,
Kenneth