Hi Moto-san,
Indeed, it looks like the AD9228 DRVDD supplies power only to the LVDS related circuits. Bringing DRVDD down-then-up should not affect register contents, but to be safe it would seem good to assume the worst if either AVDD or DRVDD have a problem.
In your system are you using default AD9228 register settings? Is your concern about having register contents corrupted by power supply problems?
Thank you.
Doug