The best way for designing, if the design goes into a software / firmware code set, is to use flow charts. Software tools that proport to "write the code for you" are in my opinion not worth the electrons your computer uses in its wires to run such software. If the design is targeted to the likes of programmable logic these tools may be of some great use.
Michael Karas

PS, I cannot tell you where to look becasue the last time a client of mine tried to force the issue of using a tool such as this I saw that the preliminary results were garbage. Thus I have never looked again!! Plus it is great fun designing and coding a state machine implementation.

MJK