How to set the pins of CDCI1624 when LVCMOS input mode employed

How to set the pins of CDCI1624 when LVCMOS input mode employed

dears,

a customer has a few questions about CDCI6214, please help to confirm:

1. they will use LVCMOS, how should we deal with PIN2(XIN) , PIN5(REFP) and PIN6(REFN) which is un-used?  Pull them down to GND?

 2. REFSEL will be used to select the input reference clock.  From the description in the datasheet as below:

When REFSEL=0,  Crystal will be select.

When REFSEL=1,  REFP&REFN will be select.

But we will use LVCMOS input mode , and one 33.33MHZ  LVCOMS clock will be connected to XOUT PIN, so, how should we deal with REFSEL and promise CDCI6214 can receive the correct input clock?

3. Will Y0 be output anyway and no need any configuration ?

4. Is there any design guidance for CDCI1624?

thanks!