Karnaugh Map (K-Map)

2 Column CSS Layout - concise design

Karnaugh Map (K-Map):

One variable, two variable, three variable, four variable:





Representation of truth table on karnaugh map:

Plot k-map fot the expression:

Y = (A+ B+ C+`D) (A+`B+`C+ D) (A+ B+`C+`D) (`A+`B+ C+ D) (`A+`B+`C+ D)

Grouping 2 adjacent cell:

Y=`A`B`C D + A`B`C D

 = `B`C D (`A + A )       {RULE `A + A=1}

 = `B`C D




Y=`A`BC+`ABC+ABC

 =`A`BC+ `ABC+ `ABC+ ABC

 =`AC(`B+B)+BC(`A+A)   {RULE A+A=A}

 =`AC+BC

Grouping 4 adjacent cell:


Y=`AB`CD+ `ABCD+ AB`CD+ ABCD

 =`ABD(`C+C) +ABD(`C+C)

 =`ABD+ABD

 =BD(`A+A)

 =BD


Grouping 8 adjacent cell:


Reduce the following expression to its SOP?

Y=`A`B`CD+ `ABCD+ `ABCD+ `ABC`D+ AB`C`D+ AB`CD+ ABCD+ A`BCD?

Reduce the following expression to its POS?

Y=(A+B+`C) (A+`B+`C) (`A+`B+`C) (`A+B+C) (A+B+C)?


UNIT 2 Digital logic circuit

2 Column CSS Layout - concise design

Boolean Theorems:

DeMorgans Theorems

He suggest tha two teoream that forms an important part of Boolean algebra.

In the equation form

1 . `A`B   = `A   + `B

The complement of the product is equal to the sum of the complements.

A

B

`A`B  

`A  + `B

0

0

1

1

0

1

1

1

1

0

1

1

1

1

0

0

 

2 . `A   + `B =`A`B  

The complement of the sum is equal to the product of the complements.

A

B

A  + `B

A`B  

0

0

1

1

0

1

0

0

1

0

0

0

1

1

0

0

 

 

 


Multiplexer

2 Column CSS Layout - concise design

MULTIPLEXER:

It select one of the input, it route to the output is known as data selector.

There are 2*n input lines and n selection lines whose bit combination determine which input line is selected.

Multiplexer is many to one (many input but one output).


2:1 MULTIPLEXER:


D0 is applied as an input to one AND gate and D1 is applied as an input to another AND gate.

Enable input is applied to both the gate.

An inverted S is applied to second input to first AND gate.

Selection line S is connected tas second input to second AND gate.

Output of both the AND gates are connected as input to the OR gate.

4:1 MULTIPLEXER:


8:1 MULTIPLEXER:


Design 16:1 multiplexer using 4:1 multiplexer ?


Implement the given function using multiplexer ?

 

 

 

 


Application of MULTIPLEXER:

They can be used to implement combinational logic circuit.

They are use in time multiplexing system.

They are used in frequency multiplexing system.

They are used in A/D or D/A converters.

 They are used in data acquisition system.

MULTIPLEXER  IC’S:

IC number

Function

74150

16:1 MUX

74151

8:1 MUX

74153

Dual 4:1 MUX

74157

Quad 2-inp MUX