AD9551 question


I am trying to program AD9551. Our instrument board has a AD9551 on it and the board design around AD9551 is as below;

external crystal feeds 25 Mhz signal to external crystal input, RefA has 100 Mhz signal from board, RefB is not connected, and

all A/B/C static control pins are not connected.  I am trying to get 16.384 Mhz signal and I used the EVM software to get the control register settings. I attached the screen capture of the EVM software where control register values are displayed.

After programming the control registers with values from the software, I see 12.7 Mhz signal at output1 pin instead of 16.384Mhz and both lock (input/output pll lock signals) pins stays low.


Please, advise.