4.1.2 MPU Clocks

Two clock sources are necessary for the module microcontroller:

• 24-MHz main oscillator for the SAMA5D27 MPU
• 32.768-kHz oscillator for slow clock oscillator input and embedded RTC of the SAMA5D27 MPU

The 24-MHz clock is generated by a Microchip ultra-low power MEMS oscillator DSC6003HI2B-024.0000T. It delivers a 24-MHz clock to the SAMA5D27 with an ultra-low power consumption of about 1.3 mA in Active mode.

For more information about the MEMS DSC60XXB, see Reference Documents. This section lists the sole reference documents for product information on the clock generation of the Microchip SAMA5D27 SOM.

The 24-MHz clock can be enabled/disabled as required by the application through the SAMA5D27 PD23 GPIO.

• By default, as the GPIO is in Input Pull-Up at reset, the clock is enable.
• To disable the clock, the GPIO must be forced to "0" logic.

The 32-kHz clock is generated by a small size crystal. It delivers an accurate 32-kHz clock to the SAMA5D27 MPU for its embedded RTC.