DS280DF810EVM: Clock and prbs function question

Part Number:DS280DF810EVM

Now i'm trying to use DS280DF810EVM.

1. Does i need to feed the external clock source( 25M )to the DS280DF810EVM via clock_in or the DS280DF810EVM has the internal reference clock?

2. When i enables the PRBS function where will the data come out TXnP and TXnN? 

3. Could i use the internal PRBS function to test the On-chip eye monitor?

Thanks.