2.6.9. Pipeline Logic to Reduce Glitching
Long chains of cascaded logic blocks can create glitches due to path delay differences between the input signals. Inserting Flip-Flops to cut these long chains terminates the propagation of glitches to consecutive logic cells.
Circuits that heavily use of XIO functions (for example, Cyclic redundancy check) tend to glitch significantly when cascaded. Add pipeline registers or re-architect to reduce signal toggling