Boot without external RTC

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Boot without external RTC

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AdrianMerrath
Contributor III

Hello,

we designed our own i.MX 8M Hardware and it is not possible to boot without an external 32kHz clock. When we connect a external 32kHz clock there are no Bootproblems.

The Datasheet says: "When an external RTC clock input is not present, the 32 kHz clock for internal logic is generated by the 25 MHz oscillator".

Is this a known issue?

Thanks in advance.

Best regards,

Adrian

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Yuri
NXP TechSupport
NXP TechSupport

Hello,

   External RTC clock is mandatory.

All three clock sources (RTC clock,  XTAL 25M, XTAL 27M) are mentioned explicitly

as must be running in the i.MX8M Hardware Developer’s Guide.

  The Datasheet(s) should be updated in order to remove the following statement:

"When an external RTC clock input is not present, the 32 kHz clock for internal logic

is generated by the 25 MHz oscillator".


Have a great day,
Yuri

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112 Views
Yuri
NXP TechSupport
NXP TechSupport

Hello,

   External RTC clock is mandatory.

All three clock sources (RTC clock,  XTAL 25M, XTAL 27M) are mentioned explicitly

as must be running in the i.MX8M Hardware Developer’s Guide.

  The Datasheet(s) should be updated in order to remove the following statement:

"When an external RTC clock input is not present, the 32 kHz clock for internal logic

is generated by the 25 MHz oscillator".


Have a great day,
Yuri

-----------------------------------------------------------------------------------------------------------------------
Note: If this post answers your question, please click the Correct Answer button. Thank you!
-----------------------------------------------------------------------------------------------------------------------

View solution in original post

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AdrianMerrath
Contributor III

Hello Yuri,

thank you very much for your help. This is an important information for our redesign.

Best regards,

Adrian

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