10.1 Ethernet Clocks

Two clock sources are necessary for the Ethernet functionality:

A small size 25-MHz crystal is used to generate the main clock of the Gigabit Ethernet Transceiver LAN8840T-V/PSA.
A small size 125-MHz MEMS oscillator (DSC1501MI2A-125.0000) is used to generate the clock source of the SAM9X75 MPU Gigabit Ehernet functionality. This functionality is externally controlled by GPIO 125MHz_EN (pin 22).

The online versions of the documents are provided as a courtesy. Verify all content and data in the device’s PDF documentation found on the device product page.