Can we generated a LUT based clock mux that can be glitch free ?
I would like to switch 3-4 clocks at 100-200 Mhz. The mux can be made glitch free using registers, but can we do away with the registers (depending on certain considerations) and still get a glitch free LUT based clock mux ?
1 Answer
No. A glitch-free mux is a state machine, which means that one way or another, it must have internal feedback, creating latches.
While it is possible to build asynchronous state machines using LUTs only, the tools will complain mightily, and the performance will be worse than if you use actual registers (FFs).