For a breadboard, we would like to duplicate the programmation part of the nRF52840 dev. kit.
Can you provide the layout of the dev. kit in electronic form (Mentor or Altium) ?
Can you provide as well the PCA10056 preprogrammed ?
bonnet said: the programmation part of the nRF52840 dev. kit
You mean the on-board J-Link ?
I don't believe that you would be able to buy the J-Link chip, so there is probably no point in doing this.
Why not just use the on-board J-Link on the DK? It can be used to program external Nordic devices ...
You can find the schematic and layout HW files for the nRF52840 DK on the nRF52840 DK product page . There you should also find the FW image that runs on the OB chip.