Why is RESETREAS showing soft reset (x00000004) after reprogramming and running the firmware on nRF52DK (bootloader included)?

[Vankata]

Hi,

I am developing a firmware for nRF52832, in which the device reset reason matters. I am reading the RESETREAS register to identify it but I observe something strange to me. If I reprogram the nRF52DK, and run the firmware from the SEGGER Embedded Studio (5.50a), the reset reason is always 0x00000004, i.e. soft reset (bit 2). If I press the reset button on the kit, the register is read as expected - 0x00000001 (reset pin), but again after reprogramming, it shows 0x00000004. Why is that? What am I missing? I also have the bootloader installed. If the bootloader influences the register content, why it doesn't do that when I am pressing the reset button? Is this something related to the usage of the Studio?

Regards

[Bendik Heiskel]

Hi,

At the end of the flashing procedure a soft reset is used to reset the device. This is causing the RESETREAS to show a soft reset at the first boot after programming.

 
Best regards,

Bendik

[Vankata]

Thank you! It's was a bit confusing, though as I used to consider the soft reset as result of a execution of a code in the target device, but perhaps it is done by the programmer via direct writing into the corresponding NVIC register?