AMIC120: About RTC clock source

U-SK

Genius 5840 points

Part Number: AMIC120

Hello,

If we want to use RTC and set RTC-Only mode, can we use internal clock source as RTC clock signal?

Is external oscillator or crystal needed?

Is there an internal oscillator that can also operate in RTC-Only mode?

Regards,

U-SK

over 7 years ago

0 Biser Gatchev-XID over 7 years ago

TI__Guru**** 393215 points

Hi,

The clock reference for the RTC can be sourced from an external crystal (used with the 32kHz RTC Oscillator), an external 32KHz oscillator, or from the Peripheral PLL. Please read section 19.4.3.2 in the AM437x TRM Rev. H.

0 Biser Gatchev-XID over 7 years ago in reply to Biser Gatchev-XID

TI__Guru**** 393215 points

To answer your question:
The Peripheral PLL will not be operational when the device is placed in RTC-Only mode. Therefore you will need either an external 32.768kHz crystal, or an external 32.768kHz oscillator.

0 U-SK over 7 years ago in reply to Biser Gatchev-XID

Genius 5840 points

Hi Biser,

Thank you for your reply.
How about Standby Mode or Deep Sleep Mode?

Regards,
U-SK

0 Biser Gatchev-XID over 7 years ago in reply to U-SK

TI__Guru**** 393215 points

In Standby mode all DPLL's are placed in Bypass. In DeepSleep mode the PD_PER power domain is OFF. Therefore the Peripheral PLL will not be operational in both modes. See Table 6-13 in the AM437x TRM Rev. H.

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AMIC120: About RTC clock source