RST Pin for SWD interface is necessary?

[Lakerno]

I am using the Segger interface for designing an nRF52 based device. I am planning to use SWDIO SWCLK VTref and GND pins on my device. Is it necessary to connect the nRESET pin to the Reset pin of the NRF52 chip? If I dont connect this, will there be any issue with programming/flashing the device? what are the advantages/disadvantages? Can anyone kindly elaborate on this?

thank you!

[Michael Dietz]

No - it is not necessary to connect the nRESET pin to the RESET pin on the nRF52 chip.

The nRF51 had a SWD protocol that was not standard - the reset was multiplexed on the SWDIO lines.

This is not the case with the nRF52, the SWD interface is standard. Now you have the option to configure a GPIO pin (pin 21 by default) as a reset pin. This is not required though. SEGGER or any other programming tools don't need a reset pin. They reset the device by writing CPU registers and through SWD commands (sysResetReq).

-Mike

[Michael Dietz]

no, it does not support this.