31.5.4 Bypassing the 8 to 24 MHz Crystal Oscillator

Prior to bypassing the 8 to 24 MHz crystal oscillator, the external clock frequency provided on the XIN pin must be stable and within the values specified in the XIN clock characteristics. Refer to the section “Electrical Characteristics”.

The sequence to bypass the crystal oscillator is as follows:

  1. Ensure that an external clock is connected on XIN.
  2. Enable the bypass by setting CKGR_MOR.MOSCXTBY.
  3. Disable the 8 to 24 MHz crystal oscillator by clearing CKGR_MOR.MOSCXTEN.