fractional spur question

[super]

Dear all:
1. In fractional-N pll design ,
fref=240khz ,N=100, K=3,F=8 Fout=fref*(N+K/F)

Fractional spur is 30khz or 90khz ?

2. delta-sigma clock is from Fref or Fdiv-vco ?
In ADI is show from Fref , but TI show from Fdiv-vco.
I have some confuse.

thanks