Where in the source can I see what happens when RST pin is invoked?

For a project, I am trying to establish what the reset concept is on the Argon/Boron. Looking at the Boron schematic:

I see the nRF can pull the UBLOX reset line, and the RST pin only pulls the nRF reset line, so I need to se what the SW does when that happens.

I have searched the forum and docs for this, and have also skimmed through the source code for a few hours without finding it, so any help would be appreciated. Thanks.

There is no code run when the /NRF_RESET pin on the nRF52 is brought low. It’s a hardware reset of the MCU. There is no software cleanup done before reset.


I am looking for what happens in SW when the nRF starts up after the reset?

Ok, let me narrow it down a bit. I am not familiar with the source code and so this may be a completely stupid question, but I was hoping not to have to install the whole build system and all sources to find this info.

I am interested to know what peripherals are reset by the SW running on nRF, when starting up in normal mode after the RST pin is released.

I found the code for the boot loader where registers are loaded/set, what mode to initiate if buttons are pressed (DFU etc.). I can’t seem to find where peripherals are reset by the nRF like the PMU, modem etc. Could be because it never happens during startup.

@thrmttnw, the initialization code is most likely done by the Nordic SoftDevice software stack (which also includes FreeRTOS) so it won’t be obvious. I’m not sure the source code is in the Particle DeviceOS repo so you would need to download the SDK from Nordic to get to the source code.

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In that case I am not finding out what happens when the RST pin in pulled on the Boron, other than the nRF itself is reset. I was hoping more info was available without going through the full code base.

An alternative then is to design in a reset IC to instead pull the Boron EN pin for long enough, to make sure every thing is re-set when needed.

@thrmttnw, that is one approach taken by other members. Some members are using a TLP5010 watchdog chip like this:

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