How to use RTC component (RTC_LDD) with internal or external oscillator?

[durgeshtanuku]

I have my freedom board(KL25Z128) without any oscillator connected to PTC1 and PTC3. I have found tutorials on "how to use RTC component with ERCLK32K, by connecting oscillator between PTC1 and PTC3". But i don't have crystal with me. So I have tried to take internal oscillator in component inspector settings. I have encountered an error " Not supported by hardware". I am attaching the screen shot of the error i have encountered. Help me in solving this issue.

regards,

Durgesh

[ankur_kala]

Hi,

The time counter within the RTC is clocked by a 32.768 kHz clock sourced from an external crystal using the oscillator. You can not use internal RC for RTC.

Please go through the functional description of RTC module in the RM for further configuration settings.

If this post helps you, kindly mark it as correct/helpful answer.

Regards,

Ankur

[durgeshtanuku]

Thanks For your reply,

After reading the manual, I think the ERCLK32K can be sourced from OSC32KCLK. And we can use ERCLK32K as input to the RTC clock as source. There is also another souce LPO.

So can i use OSC32KCLK or LPO?

[ankur_kala]

HI Durgesh,

Yes you can use OSC32KCLK or LPO as the clock source for RTC. Please read section 5.7.3 RTC Clocking for more information.

Regards,

Ankur

[durgeshtanuku]

I have tried to use OSC32KCLK using RTC_LDD(In RTC component settings i have selected ERCLK32K for RTC source and in cpu settings I have selected OSC32KCLK as clock source for ERCLK32k)  component, but it is giving error.

[adriancano]

Hi,

You can refer to this document to use the MCGIRCLK as the source of the RTC in the RTC_CLKIN:

Using RTC module on FRDM-KL25Z

I hope this information can help you.

Regards,

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