When should I choose a Mealy or Moore state machine?

[EvLer]

What are some possible criteria when to choose Mealy or Moore state machine?
I know that for Mealy, output is a function of present state and input and in Moore it's just present state. I know it also probably depends on the design specifications, but ... just wondering.

Any insights are very much appreciated.

 

[mezarashi]

It's difficult to say in general other than that given definition. It's important to be able to identify how a machine works and knowing whether it is Mealy verus Moore is part of it. For design purposes, you can see that a machine that has output as a function of state only is somewhat 'better' due to its synchronous nature. Moore machines usually have the output and input buffered by some kind of sequential logic (flip-flops and latches), while Mealy machines usually have part of the output directly coming from the input through some combinational logic.