1. CS 140L Lecture 7 Transformation between Mealy and Moore Machines
Professor CK Cheng
CSE Dept.
UC San Diego

2. Outlines Framework Procedure Example: Transform Example: State Diagram
Example: Output Sequence

3. Transform from Mealy to Moore Machine
Mealy Machine: y(t) = f(x(t), s(t))
Moore Machine: y(t) = f(s(t))
s(t+1) = g(x(t), s(t))
x(t)
x(t) C1 C2
y(t) C1 C2
y(t)
CLK
CLK
s(t)
s(t)
Moore Machine
Mealy Machine

4. Transform from Mealy to Moore Machine
Algorithm
Input: State Table of Mealy machine
1) For each NS, z = Si,yj create a state Si(j)
2) For each new state Si(j), repeat the row PS = Si
3) Replace NS, z = Si,yj with state Si(j).
Set output z = yj for row PS = Si(j)

5. Example Mealy Machine: Moore Machine: PS A B 00 A,0 A,1 01 A,1 B,0 10
(x,y)
(NS, z)
Moore Machine: PS A0 A1 B
(x,y) 00 A0 A1 01 A1 B 10 B z 1

6. State Diagram Mealy Machine Moore Machine A B A0/0 A1/1 B/0 00/0, 01/1
10/0 B
00/1
00/0, 01/1
10/0, 01/0
Mealy Machine
A0/0
A1/1
B/0 10 00 01
Moore Machine

7. Timing Diagrams
Time step x y S z A A0 1 A A0 2 1 A A1 3 B 1 4 1 A A1 5 1 A A1 A
Mealy A1 1
Moore
The output shifts by one clock from Mealy to Moore machine