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How to keep RTC ticking when wakeup enabled?

DOCon.1
Senior

Is there a way to make the RTC continue keeping time while the wakeup timer is enabled? On my end, time freezes whenever the `cr.wute` bit is set.

The RTC is listed as frozen in init mode, but It's not in init mode. It could be a shadow register issue, but it appears the clock is legit frozen until I disable the wakeup timer. Is it only capable of keeping time when the wakeup timer is inactive? What do you think could cause this? Thank you.

2 REPLIES 2

Which STM32?

> On my end, time freezes whenever the `cr.wute` bit is set.

How do you observe that? Do you read date after time? Try to read out all the RTC registers and check.

> The RTC is listed as frozen in init mode

How? Where?

JW

DOCon.1
Senior

The program I'm using has 2 modes: One in which the program has WUTE enabled, and another in which it doesn't. Time ticks normally in the WUTE-disabled state, but is frozen when in the WUTE-enabled state. If I disable WUTE in the disabled state, time ticks normally there as well.

Re init mode freezing the time, from the RM: "Set INIT bit to 1 in the RTC_ISR register to enter initialization mode. In this mode, the calendar counter is stopped and its value can be updated.". I'm not sure if it's just the date registers, or date + time.

I've read out the time/date registers - they're frozen whenever the wakeup timer is enabled.