RAM retention after a pin reset

[buddi_nordic]

I have a design using nRF52832, and I'm hoping to use RAM set before a pin reset is applied. But, at least with a debugger attached, RAM appears to be randomised through a reset.

This is with the S132 softdevice present. I can keep noinit through a soft reset, not a pin reset.

I've tried setting RAM[n].S0RETENTION/S1RETENTION, but those get reset when the pin reset hits.

Does the nRF52832 not keep RAM through a pin reset? Is there some way I can do this?

[Jørgen Holmefjord]

Hi,

RAM is not retained through a pin reset, you can see a table of which peripheral is reset by each reset source on this page.

The SxRETENTION registers are used to turn on/off RAM retention during System OFF mode.

If you need to retain data through a pin reset you need to store it in flash. The FDS library can be used for this.

Best regards,
Jørgen

[buddi_nordic]

Hi Jorgen,

Thanks for the response. I did see that table, but couldn't interpret it, there is nothing saying what the 'x' means. It should be interpreted as not retained then? I see that it is amrked as not retained through a watchdog reset too?