1. ECE 287 – Lecture 14
Finite State Machines - I

2. Announcements
•
•
•
•
Next Quiz on Wednesday after Exam
Exam II – Nov 15th
Last Day to Demo Labs – Nov 14th
Project Oral Proposal - Nov 1st

7. START
Robot control
Approach
Ask Name
False
Response?
True
Small Talk
False
Sense
Compatibility?
True
False
Ask on Date/
Contact
True
SUCCESS

8. 1) System of inputs, outputs and states
•
Peter: Assume input for question and input
for if action complete

9. 2) State Diagram

10. 3) Encode States

11. 4) State table

12. 5) Build Circuit

13. State Machine Generalization
Inputs
outputs
Combinational
circuit
Current
State
Next
State
State

14. Example 2
Turn a light on every 4 cycles of a clock using a
state machine

15. Problem Set
1. Build a finite state machine for the following state diagram:
In = 0
In = 1
In = 0
B
Out = 1
A
Out = 0
In = 0
In = 1
G
Out = 1
In = 1

16. Problem Set
1. Build a finite state machine for:
•
Design a state machine controller for an elevator. The elevator can be at one of two
floors: Ground or First. There is one button that controls the elevator, and it has two
values: Up or Down. Also, there are two lights in the elevator that indicate the current
floor: Red for Ground, and Green for First. At each time step (clock), the controller
checks the current floor and current input, changes floors and lights in the obvious way.