fractional divider model !

[prescaler]

hello,everyone,
i need some helps,i 'm building a fractional-n pll model in simulink which divides wide frequency range,so i adapt mash with multi modulus divider which contains swallow and programmable counter.but when i building the swallow and programmable counter in simulink ,ican't find any propriate dff which can pre-set value,so how can i get a adequate dff,pls give me some adivce!
thanks a lot!

 

[prescaler]

nobody knows?

 

[fanshuo]

Is it possible to add another clock to trigger some switch to do that?

 

[prescaler]

how to add?please give me some clues,thanks!