RTC2 continues to operate in Application after Bootloader execution

RE: RTC2 continues to operate in Application after Bootloader execution

Denis Shreiber — Thu, 08 Apr 2021 09:07:18 GMT

Thank you, Hung! 👍

I understood the root of the problem.

It would be nice if stop RTC2 was implemented in Bootloader in future releases of SDK 🙂

RE: RTC2 continues to operate in Application after Bootloader execution

Hung Bui — Thu, 08 Apr 2021 08:45:43 GMT

Hi Denis,

Calling nrf_bootloader_wdt_init() will trigger the nrf_bootloader_wdt_feed_timer_start() which starts the RTC2 to feed the watch dog. This explain why you see the RTC active in many cases.

What you can do is before nrf_bootloader_app_start() called in the bootloader, you can stop RTC2. This way you don't need to implement the code to stop RTC2 in your application.

RE: RTC2 continues to operate in Application after Bootloader execution

Denis Shreiber — Thu, 08 Apr 2021 03:29:00 GMT

The RTC2 keep running:

After OTA DFU
After downloading and running firmware via j-link
After click Restart in debugger in SES
After selfreset by NVIC_SystemReset()

The RTC2 is in reset state:

After reset by PINRESET
After reset by Watchdog
If there are no Bootloader in internal flash

I did make some changes in Bootlodaer. May be this is a reason:

I enabled WDT by adding nrf_bootloader_wdt_init() to the first line in main

I attached sdk_config.h file of Bootloader

devzone.nordicsemi.com/.../3583.sdk_5F00_config.h

RE: RTC2 continues to operate in Application after Bootloader execution

Hung Bui — Wed, 07 Apr 2021 14:26:43 GMT

Hi Denis,

When do you see that RTC kept running after the bootloader ? Was it on a normal booting or it's right after a DFU update ?
As far as I know in SDK v16 (and newer) the bootloader will trigger a reboot after it receives the image. This reboot will reset all the peripherals that the bootloader uses including the RTC2.
On a normal booting RTC2 shouldn't be running as the bootloader would go straight to the application.