get time in us using RTC

Hello

I am trying to get a time in us using the RTC. I have used the function available in RTC application note "DA1468x_RTC_concept_tutorial_v1_00.pdf":uint64_t sw_rtc_convert_lp_to_time(uint64_t
lp_clocks)。我在“LP_CLK_RCX”模式(/* Check whether the lp clock source is the internal RCX */) and this function uses the global variablercx_clock_period:


/*
* Use the variable named [rcx_clock_period] to get the
* current RCX period in usec. Please note that this value
* is multiplied by [1024 * 1024]
*/
time = (lp_clocks * (uint64_t)rcx_clock_period);
time = (time >> 20); // divide with (1024 * 1024)


Inidlemode, the time returned is always higher than the previous time got 50ms before.
Inextended sleepmode, the time is sometimes smaller than the previous time got 50ms before. So I return to the past.

This is due to the auto-re-calibration when exiting extended sleep mode ofrcx_clock_period。
Do you have an idea about this use case?

Best regards,
Guillaume B.