9.2 MPU Clocks
Two clock sources are necessary for the module microprocessor:
- A 24-MHz main oscillator to generate the SAMA7G54 MPU main clock
- A small size 32.768-kHz oscillator to generate the slow clock oscillator input and feed the SAMA7G54 MPU embedded RTC
The 24-MHz clock is generated by a Microchip Ultra-Low Power MEMS oscillator DSC6001HI1B-024.0000T. The 24-MHz clock is delivered to the MPU with an ultra-low power consumption of about 1.3 mA in Active mode.
For more information, refer to the DSC60XXB MEMS data sheet (see Reference Documents).
The 24-MHz clock can be enabled/disabled as required by the application through the 24M_EN signal available on pin 98.
Three configurations are available:
- 24M_EN pin connected to VDD (VDD_3V3). The clock is enabled.
- 24M_EN connected to GND. The clock is stopped.
- 24M_EN connected to a GPIO. The clock is dynamically controlled by software.
The 32.768-kHz clock is generated by a small size crystal. An accurate 32.768-kHz clock is delivered to the SAMA7G54 for its embedded RTC.