NRF52840 Soft Reset Ram Retention

[LukeC]

I am working on putting my NRF52840 to sleep with the RTC running (System ON WFE, not System Off).  

According to the datasheet, I should be able to call a soft reset and keep my RTC count variable in RAM. 

However, when debugging this, my RAM rtc count variable is cleared.

Is this perhaps just a bug in debugging/watching variables?  Do I need a tweak the SES startup call that might be resetting the RAM?

I am calling  NVIC_SystemReset();

to induce a soft reset, is this correct?

Thanks!

IDE: SES

[Sigurd]

Hi,

Typically, variables in RAM gets zero initialized during the reset sequence. If they are placed in the .non_init section they will not get zero initialized. You might find this post useful.

[LukeC]

This worked, I just needed to define my variable in the non_init section

static uint32_t m_time __attribute__((section(".non_init")));