17.6.8.5 Reference Clock Switching
When a software operation requires reference clock switching, the normal operation is to disable the FDPLL96M, modify the DPLLCTRLB.REFCLK to select the desired reference source and activate the FDPLL96M again.
When a software operation requires reference clock switching, the normal operation is to disable the FDPLL96M, modify the DPLLCTRLB.REFCLK to select the desired reference source and activate the FDPLL96M again.