i.MX9 - is 32.768kHz clock input necessary?

[jsopenrb]

Can i.MX9 work with only 24MHz clock if no low power/stand-by mode is needed and an external RTC is present?

[Chavira]

Hi @jsopenrb!
Thank you for contacting NXP Support!

Is not necessarily an external signal because the processor has an internal oscillator.

Please check the Hardware User Guide and Datasheet for how to use the internal signal.

The external signal is recommended because we can have more accuracy on the signal but you can use the internal oscillator.

Best Regards!
Chavira

[jsopenrb]

Thanks for the reply. Can you point the exact place in the documentation where this is stated? All I could find is that RTC clock (32.768kHz) is required.

[Chavira · Accepted solution]

Hi @jsopenrb!

In chapter 4.1.6.1 of the Datasheet, you can see the requirements for the crystal/ external clock for 24 MHz and 32.768 KHz, and chapter 4.1.6.2 mentions the oscillators on the chip.

Answering the questions an external clock is not required since there exists an internal clock for that purpose, but is recommendable the external clock to obtain a better accuracy on the clock sources.

Best Regards!
Chavira