[time-nuts] Wikipedia Dual-modulus prescaler item

[Peter Vince]

David Forbes recently mentioned the Wikipedia item on dual-modulus
prescalers:

     http://en.wikipedia.org/wiki/Dual-modulus_prescaler

I have looked at that article, and either my brain has slipped out of
gear, or there are some errors in both the diagram and the words:-(  I
think I can see the sort of thing they are trying to achieve, but was
hoping someone here could provide a clearer explanation please?

Thanks, Peter