What is the cause of reset reason 0x01?

[arshi]

My device is getting reset when left idle for sometime. On checking the logs, I see that the nrf_power_resetreas_get() returns reset reason as 0x01. I am using NRF SDK 17.1.0. 

What does reset value 0x01 signify?

[Jørgen Holmefjord]

Hi,

The reset reason comes from the RESETREAS register.

0x01 means bit A is set, which means a pin reset was detected.

Best regards,
Jørgen

[arshi]

My device was left idle without any BLE interrupts. Any idea about what might be the possible causes of pin reset?

[Jørgen Holmefjord]

This bit should only be set if the reset pin was pulled low. This should not be caused by SW.

Is this on a custom board? Have you enabled the reset pin on the chip? Is the reset pin connected to anything?

[arshi]

Yes this is a custom board. No I haven't enabled the reset pin.

[Jørgen Holmefjord]

Can you confirm that reset pin is not enabled by reading out PSELRESET[0] and PSELRESET[1] registers?

E.g., if enabled it should have this values, if disabled, they should be 0xFFFFFFFF.

nrfjprog --memrd 0x10001200 --w 32
0x10001200: 00000015                              |....|

nrfjprog --memrd 0x10001204 --w 32
0x10001204: 00000015                              |....|