EECS20N: Signals and Systems

State Transition Diagram

When the number of states is finite (and reasonably small), the state machine can be described by a very readable diagram. Create one bubble for each state, one arc for each transition:

state ∈ States
guard1 ⊂ Inputs
guard2 ⊂ Inputs
output1 ∈ Outputs
output2 ∈ Outputs

else = {x ∈ Inputs | x ∉ guard1 ∪ guard2 }

The else arc can be implicit if

  • it is a self loop
  • it produces the stuttering output (absent)