What the phase selection block is in a phase PLL design?

[pillar_chen]

Hi, i'll design a phase pll include three blocks: integer mode pll, delta-sigma modulator and phase selection. But i don't understand what the phase selection is. please help me, thanks in advance!

 

[ir_in]

Re: phase PLL

have a look at the link below

www.ece.wisc.edu/~vlsi/ research/ASPDAC05_Wavepipelining.pdf