Finite State Machines (Moore)

• A finite number of states and transitions
• Transitions are triggered by inputs in our case
  • But if inputs keep you in the same state, that is self transition
• Used for logic circuits that actually perform a behaviour
  • ”Tickle me Elmo” 😨

Example: Alarm

Designing

1. Make the state diagram
2. Create a state table from le diagram
3. Have flip-flop value configurations for each state
   • 15 states = $lo{g}_2(15)$ bits to store them $=4$ bits
   • The flip flops hold the current state
     • The state logic takes the old state + new inputs and updates the state in the flip flops
     • Depending on the state, we output “something”
4. Use said flip flops to represent the states; use that to make a new table
5. Make the combinational circuit for every output for each flip-flip input
   1. State logic: Figuring out “the next state depending on current state and inputs”
   2. Output logic: “figuring out the output depending on current state and inputs”

Example: Sequence Recognizer

• The K maps are easy enough to get from the columns.