Dithering Circuit and glitchy multiplexers

[buzzly]

hi! i'm designing a dither circuit using maxplus 2...anyway i'm using 4 look up tables as a pipeline to get my spatial dither values. And i'm using a multiplexer swithed by a counter connected to the clock to select between them. The problem with the multiplexer is that it's very glitchy... so i cannot increase the clock frequency which was the whole purpose of the pipeline. What can i use in place of the multiplexer or what can i add to reduce the glitch?

 

[melone]

Could you define glitchy? Are the signals going into the mux corrupted with spikes? Is it the output?

 

[buzzly]

sorry... the input to the mux is from a set of dflipflops so its clean... the output is glitchy. If I sample the mux output with another flip flop, it will only be the correct value if I sample it quite slowly. The mux is selecting between 4 4bit bus lines... i hope that's enough info...and thanks for replying