In Soc power related question

During the learning of Soc doc. I have a one question on that.
Qus : Consider in a chip level we can concentrate both power and inside the blocks we concentrate clock. both the clock and power should enabling purpose only. power we consider in analog and clock we consider in digital. So in my question is how the synchronization is happening during the initialize of particular block in the SOC.

I hope you understand

Regards,
Mariya christopher A