Dual Modulus Prescalar, point and how they work?

[blueagle91]

Hello EEV

New hear good to be part of the forum, a simple question.
I know how prescaler works. Now i figuered that because of the channel step a dual modulus is required. But if you switch it fast how does the rest of the circuit knows which ratio is used, or the ratio is basicly both in the same time because of switching speed.

Basicly how dual modulus orescaler works? Whats the point?