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LMoha.1
Associate II
April 26, 2020
Question

is there a clock in stm 32 that stays running even if the power is turned off at the MCU?

Hello

for my application I use STM32L0, and I want to retrieve the exact date without changing it every time I turn off the power. Is there a timer that was triggered on the production day of the STM MCU that will allow us to retrieve the date?

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9 replies

TDK
April 26, 2020

No clock can run without power.

The RTC clock can run on minimal power from the VBAT supply, if you configure it correctly.

> Is there a timer that was triggered on the production day of the STM MCU that will allow us to retrieve the date?

No.

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berendi
Principal
April 27, 2020

The problem is that STM32L0/STM32L1 series don't have VBAT.

LMoha.1
LMoha.1Author
Associate II
April 27, 2020

Thank you very much

Tesla DeLorean
Guru
April 27, 2020

Suspend, running LSE from your supply/battery. Clock the RTC with that.​

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LMoha.1
LMoha.1Author
Associate II
April 27, 2020

@Community member​  . But the problem is that in my application, i turn off /ON the power . is that will Reset the RTC clock?

Tesla DeLorean
Guru
April 27, 2020

The electrons are going to need to come from somewhere​

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LMoha.1
LMoha.1Author
Associate II
April 27, 2020

Ok

Piranha
Principal III
April 27, 2020

> Is there a timer that was triggered on the production day of the STM MCU that will allow us to retrieve the date?

> Ok i thought that quartz doesn't need power supply

Yes, they have a special perpetuum mobile edition for those, who don't waste their time on physics and other foolish things. Also it has an absolutely perfect accuracy and stability, therefore it always has the correct time.