State diagram for reversible mod-4-counter

[ogward]

1. Draw a state diagram for a reversible mod‐4‐counter with the following in signals.
00=stand still in the current statement
10=count up.
01=count down.
:

2. The attempt at a solution
My first problem is that I'm a bit confused about what "reversible mod-4-counter" means.
Do they mean reversible because you can count both up and down or do they mean something else?

this is my attempt.
http://img4.imageshack.us/img4/3800/20111009002.th.jpg

 

[lewando]

Reversible means up/down counter. Looks like you got it right.