divider bug in Vaucher Truly Modular Programmable Dividers

[louis.chuang]

a family of low-power truly modular

Dear all
when I use the programmable divider from the paper "A Family of Low-Power Truly Modular Programmable Dividers in Standard 0.35-um CMOS Technology", I found there is a limitaion that paper don't mention.
Though the division ratio extension is sloved, but if the sigma-delta modulator change the division ratio from 2^n to (2^n-1), the division ratio will have error. For example, when sigma-delta modulation change the division between 16 & 15 (control bit will change betwen 0010000 & 0001111), the real division ratio may not be 16 & 15.
Does anyone found this bug, or is there any other method could solve it??
Thank you very much.

 

[saro_k_82]

modular programmable dividers

There will be one clock latency as such when going from low to high., but not from high to low in this divider. There a few techniques to solve this. What was your method