written 7.8 years ago by | modified 2.8 years ago by |
Mumbai University > Electronics Engineering > Sem 3 > Digital Circuits and Design
Marks: 10M
Year: Dec 2015
written 7.8 years ago by | modified 2.8 years ago by |
Mumbai University > Electronics Engineering > Sem 3 > Digital Circuits and Design
Marks: 10M
Year: Dec 2015
written 7.8 years ago by | • modified 7.8 years ago |
The output Y depends only on present state of memory elements.
Therefore, it is a Moore circuit.
To draw state diagram:-
Consider four states of output:-
00,01,10,11
1.Assume AB=0.0
When X=0,
$J_{A}$=B=0 | $J_{B}$=A=0 |
---|---|
$K_{A}$=B.X’=0.1=0 | $K_{B}$=A+X=0+0=0 |
.·. $A_{n+1}$=0 | .·. B$_{N+1}$=0 |
.•. Next State=00
When X=1,
$J_{A}$=B=1 | $J_{B}$=A=0 |
---|---|
$K_{A}$=B.X’=0.0=0 | $K_{B}$=A+X=0+1=1 |
.·. $A_{n+1}$=0 | .·. B$_{N+1}$=1 |
.•. Next State=01
.•. Output Y=A’.B’=1.1=1
2.Assume AB=01
When X=0,
$J_{A}$=B=1 | $J_{B}$=A=0 |
---|---|
$K_{A}$=B.X’=1.1=1 | $K_{B}$=A+X=0+1=1 |
.·. $A_{n+1}$=0 | .·. B$_{N+1}$=1 |
.•. Next State=01
When X=1,
$J_{A}$=B=1 | $J_{B}$=A=0 |
---|---|
$K_{A}$=B.X’=1.0=0 | $K_{B}$=A+X=0+1=1 |
.·. $A_{n+1}$=0 | .·. B$_{N+1}$=1 |
.•. Next State=01
.•. Output Y=A’.B’=1.0=0
3.Assume AB=10
When X=0,
$J_{A}$=B=0 | $J_{B}$=A=0 |
---|---|
$K_{A}$=B.X’=0.1=0 | $K_{B}$=A+X=0+0=0 |
.·. $A_{n+1}$=1 | .·. B$_{N+1}$=1 |
.•. Next State=11
When X=1,
$J_{A}$=B=0 | $J_{B}$=A=1 |
---|---|
$K_{A}$=B.X’=0.0=0 | $K_{B}$=A+X=1+1=1 |
.·. $A_{n+1}$=1 | .·. B$_{N+1}$=1 |
.•. Next State=11
.•. Output Y=A’.B’=0.1=0
4.Assume AB=11
When X=0,
$J_{A}$=B=1 | $J_{B}$=A=1 |
---|---|
$K_{A}$=B.X’=1.1=1 | $K_{B}$=A+X=1+0=1 |
.·. $A_{n+1}$=0 | .·. B$_{N+1}$=0 |
.•. Next State=00
When X=1,
$J_{A}$=B=1 | $J_{B}$=A=1 |
---|---|
$K_{A}$=B.X’=1.0=0 | $K_{B}$=A+X=1+1=1 |
.·. $A_{n+1}$=0 | .·. B$_{N+1}$=0 |
.•. Next State=00
.•. Output Y=A’.B’=0.0=0
Now,
State Table:-
Present | Next | State | Output |
---|---|---|---|
State | X=0 | X=1 | Y=A'.B' |
00 | 00 | 01 | 1 |
01 | 11 | 01 | 0 |
10 | 11 | 11 | 0 |
11 | 00 | 00 | 0 |
State Diagram:-