If you want to us USB the crystal should be 48 MHz. But there is problems with that from the errata. It recommends <25 Mhz crystal. So then go with an oscillator. But must limit to < 3.0 volts.
What do people out there do?
Risk it & go with a 48 MHz crystal? (How do you do a negative resistance measurement?)
Go with a 48 MHz oscillator @ 3.3V? with series resistor? value? or another LDO to < 3.0V for osc.
Go with 24 MHz crystal & PLL. But can't do USB & ethernet.
What do others do?