I would like to use the Shield Debug (P20) on the nRF52840DK as part of a Device Under Test platform for production devices. I also want to be able to transmit/receive data to/from the nRF52840 on the DK as this will be running a test program which is checking the functionality of the Device Under Test.
- Should the signals SH_VTG, SH_SWDIO, SH_SWDCLK and SH_GND_DETECT be isolated from the DUT and switched into circuit only when the DUT needs to be programmed?
- Which signal is actually responsible for causing the interface micro to switch to the SH_XXX signal path? Is it the presence of voltage on SH_VTG or SH_GND_DETECT being pulled to ground?
Thanks,