ad9508 sync_bar register bit versus sync hardware pin

The Phase Delay Control section of the datasheet says:

  Note that the phase delay adjustment requires the use
  of the SYNC function pin.

however I see that there is also a sync_bar register bit
which isn't mentioned except in the register map.

Given that the function pin has an internal pullup can
I simply float it and use the register bit when configuring
a phase delay between two outputs?