Unkwon Resets after Long runtime ; Several Hours

[krisnov]

To whom it ma concern,

we observed Unkwon Resets after Long runtime ; Several Hours.

We use the NRF52840.

After the reset bit 1 in RESETREAS is detected .

BUT investigation with a scope shows no valid change for the physical reset pin.

WE do noticed some changes in the VDD voltage but within valid working range.

I stepped over the description of the NRF52832:

Is it possible this is valid for the NRF52840 as well?

AND this behavior sets bit 1 in RESETREAS ?

Regards

Kristijan

[krisnov]

here is the right screenshot:

[Priyanka]

Hi,

I am sorry but I did not quite understand the query. The screenshot provided shows the description for RESETREAS of the nRF52840, hence it is valid for the nRF52840. Maybe you could take a look at the various reasons for reset in the documentation for RESETREAS.

Regards,

Pryanka

[krisnov]

Hi Pryanka,

Please ignore first screenshot it was sent by mistake.

I refer to the second one. The data sheet says that the bit 1 in RESTREAS is set if the reset pin is activated.

BUT we have the case that the bit is set AND the reset pin was not set.

I am asking for if this is possible and how.

Than I added the screenshot as a possible explanation (reset can be set due to voltage change of 300mV in short time). But it is from the NRF52832.

And may other question,  if the same can happen with NRF52840.

Regards Kristijan

[Priyanka]

Hi,

You could try reading the RESETREAS for understanding the reason for the reset. If it shows PIN, then the reason must be power on reset. 

There is also this errata. What IC version are you using?

-Priyanka