I visited this section afetr I encountered multiple pulses
on the border of the encoder as Eric says.
Going thru this discussion, it seems digital filtering, state mc approach implemented in CPLD is THE solution.
But all motion control people interface encoders. I was under impression that by now interfacing encoder must be standard implementaion.
Well, I will implement and come back with result, & if successful with cpld code for all.

Regards

Rajesh