9.2 MPU Clocks

Two clock sources are necessary for the SAM9X60D1G-I/LZB microprocessor:

  • 32.768-kHz oscillator for slow clock oscillator input and embedded RTC of the SAM9X60
  • 24-MHz main oscillator for the SAM9X60
Each clock is generated by a Microchip ultra-low power MEMS oscillator:
  1. DSC6102HI2B-024.0000 device: delivers a 24-MHz clock to the SAM9X60D1G. Can be enabled externally via the 24M_EN pin to control power consumption during activity.

    For more information about the MEMS DSC61xxB, see Reference Documents.

    The 24-MHz clock can be enabled/disabled as required by the application, through the 24M_EN signal available on pin 132. Three configurations are possible:
    • 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.
  2. Crystal device: delivers a 32.768-kHz clock to the SAM9X60D1G.