Watchdog Timer does not reset the device

RE: Watchdog Timer does not reset the device

roshangeoroy — Mon, 29 Apr 2024 06:51:11 GMT

Dear Einar,

You were right. Enabling power management in MCUBoot fixed the issue! I've added these configurations to mcuboot.conf.

#Power management
CONFIG_PM=y
CONFIG_MULTITHREADING=y

CONFIG_PM_DEVICE=y

I've observed that enabling only CONFIG_PM_DEVICE does the trick as well. Do you know the reason behind this?

Anyways, thanks for the fix!

Rosh

RE: Watchdog Timer does not reset the device

Einar Thorsrud — Fri, 26 Apr 2024 07:30:23 GMT

Hi Rosh,

What you describe seems likely. Have you attempted to enable power management in MCUboot to wake the QSPI flash if it happens to be in deep powr down mode after reset? In principle it should be similar to how you can handle it in your application.

Einar

RE: Watchdog Timer does not reset the device

roshangeoroy — Thu, 25 Apr 2024 07:17:39 GMT

Dear team,

I just found out the issue behind the system hang during reset. For reducing power consumption we use RAM power down library to power down unused RAM and also we power down our external flash - it has an ultra deep power down mode. During reset if these are in the powered down state the device won't boot up. This issue occurs only during software reset and not hardware reset.

The external flash being powered down affects the bootloader since bootloader(MCUBoot) checks for images in the external flash. I discovered this when I tried to disable the RAM power down and observed these logs :

00> *** Booting Zephyr OS build v3.2.99-ncs1 ***
00> I: Starting bootloader
00> W: Failed reading sectors; BOOT_MAX_IMG_SECTORS=256 - too small?
00> W: Cannot upgrade: slots are not compatible
00> W: Failed reading sectors; BOOT_MAX_IMG_SECTORS=256 - too small?
00> W: Cannot upgrade: slots are not compatible
00> I: Bootloader chainload address offset: 0xc000
00> I: Jumping to the first image slot

This causes a boot-loop.

I'm not sure why the RAM has to be powered up before reset.

I tried to include the respective power up functions for both of these in the Watchdog Callback but it does not solve the issue.

Please suggest a workaround for this issue. Since our project is battery operated, power consumption is of top priority.

Thanks,

Rosh