AD911 datasheet lists a start-up sequence (consisting of step 1 to 6, including SYSREF pulse) and a separate procedure for "NCO ALIGNMENT with SYSREF" (pag. 70) with again requires a SYSREF pulse.
When is the user supposed to send the procedure for "NCO ALIGNMENT with SYSREF"?
The request might seems trivial but, using a "try and see" approach, I didn't find a simple solution using a single SYSREF pulse.
I ended-up sending step 1 to 6 and then "NCO ALIGNMENT with SYSREF" but sometimes the LANEFIFOERR shows up (reg 0x023, Lane FIFO Error Status latched alarm when IRQEN_SMODE_LANEFIFOERR is high).