Schematic files in USRP 4-2

Hi all
when I compare two clock schematic files for different versions of USRP
pins 18,19,22 and 23 of AD9513 are used for clock_db_b_n, clock_db_b_p,
clock_db_a_n and clock_db_a_p respectively while in the last version
(USRP
4-2) I these pins are connected in the other way and clock_db_b_p and
clock_db_b_a are connected both to the negative outputs
furthermore, I could not find where is the IFCLK which is connected to
CLK0
of EP1C12
I’m wondering if anybody can help me
Thanks