Unit 2 Boolean algebra and Karnaugh maps
Boolean algebra rules and Boolean laws: Commutative,
Associative, Distributive, AND, OR and Inversion laws, De
Morgan’s theorem, Universal gates, Simplifications of Logic
equations using Boolean algebra rules and Karnaugh map (up
to 4 bit).
Lab Session: - Binary to Gray Interconversion of Logic Gates
Boolean Algebra
=A.1=A
A B ~A ~B ~A.~B (A+B) ~(A+B)
0 0 1 1 1 0 1
0 1 1 0 0 1 0
1 0 0 1 0 1 0
1 1 0 0 0 1 0
A B ~A ~B ~A+~B (A.B) ~(A.B)
0 0 1 1 1 0 1
0 1 1 0 1 0 1
1 0 0 1 1 0 1
1 1 0 0 0 1 0
y= A.B+C.D = SOP
Y=(A+B).(C+D) = POS
4 2 1
0 0
0 1
A B Y
0 0 0
0 1 0
1 0 0
1 1 1
0
0
1
1
A
B
Y=A.B
3 INPUTS A, B AND C x yz
Y IS THE OUTPUT
Y=1 when inputs is >=4
Represent in kmap
0 00
1 01
3 11
2 10
3 INPUTS A, B AND C
Y IS THE OUTPUT
Y=1 when of the inputs is >=4
Represent in kmap
A B C Y
0 0 0 0
0 0 1 0
0 1 0 0
0 1 1 0
1 0 0 1
1 0 1 1
1 1 0 1
1 1 1 1
4 2 1
3 INPUTS A, B AND C
X & Y ARE THE OUTPUT
X=1 when inputs ARE >=4
Y=1 when inputs ARE <=4
Represent in kmap
INPUTS OUTPUTS
A B C X Y
0 0 0 0 1
0 0 1 0 1
0 1 0 0 1
0 1 1 0 1
1 0 0 1 1
1 0 1 1 0
1 1 0 1 0
1 1 1 1 0
4 2 1
FOR Y =A’+C’.B’
C’ C
AB C 0 1
A’B’ 00 1 1
A’B 01 1 1
AB 11 0 0
AB’ 10 1 0
Y= C + AB
Octet : 3 variables are
eliminated
Quad: 2 variables are
eliminated
Pair: 2 variables are
eliminated
BC…> 00 01 11 10
A
0 1 1
1 1 1 1
Hence for 3-bit code converters,
4 2 1
G2
B2 B1B0 00 01 11 10
0 ~B2 0 0 0 0
1 B2 1 1 1 1
G2= B2
G1= B2. ~B1 + ~B2.B1
= B2 XOR B1
G0= B1.~B0 + ~B1.BO
=B1 XOR B0
G1
B2 B1B0 00 01 11 10
0 ~B2 0 0 1 1
1 B2 1 1 0 0
G2= B2
G1= B2. B1’ + B2’.B1
= B2 XOR B1
G0= B1.~B0 + ~B1.BO
=B1 XOR B0
B1’B0’ B1’B0 B1B0 B1B0’
G0
B2 B1B0 00 01 11 10
0 ~B2 0 1 0 1
1 B2 0 1 0 1
G2= B2
G1= B2. ~B1 + ~B2.B1
= B2 XOR B1
G0= B1.B0’ + B1’.BO
=B1 XOR B0
110
100
Same=0
Different=1
421
Same i/p = 0 output
different i/p’s = 1 output
• B2 b1 b0
1 1 0 binary ------ gray
………………………….
1 0 1
• G2 g1 g0
Same i/p = 0 output
different i/p’s = 1 output
• g2 g1 g0
1 1 0 gray------ bin
………………………….
1 0 0
• b2 b1 b0
Unit 3: Introduction to
Combinational Circuits
Introduction to Combinational Circuits Basic Logic gates
(NOT, OR, AND) & derived gates (NAND, NOR, EXOR)
Symbol and truth table, half adder, full adder, Half
subtractor, Four bit parallel adder. Multiplexer (4:1),
demultiplexer (1:4) and their applications, Code
converters - Decimal to binary, Hexadecimal to binary,
BCD to decimal, Concept of Encoder & decoder. Lab
Session: - To Study 4: 1 Multiplexer and 1 : Demultiplexer
To Study nibble adder and Subtractor circuit
Learning Philosophy : Logic gate
• A is input and Y is output
• Y= ~A
Y= A*B
n= no.of i/p’s
2^n input combinations in truth table
Y=a+b
• Y
• Y= ~(a.b)
• Y=____
• Y =A*B = ~(A*B)
____
A*B
• Y=(a+b) ____
A+B
Y=~a*b + a*~b
OUTPUT=0 if input contains even no.of 1’s
OUTPUT=1 if input contains odd no.of 1’s
• 0110 1101
• Y= ~a*~b + a*b
• 8 4 2 1
• 16 A B C D Y
• 0 0 0 0 0
• 1 0 0 0 1
• 2 0 0 1 0
• 15 1 1 1 1
A Y
0 1
1 0
A B Y(NAND)
0 0 1
0 0 1
1 0 1
1 1 0
A B Y
0 0 0
0 1 0
1 0 0
1 1 1
AND GATE USING NAND
GATE
• Y= NOT[(NOT A).(NOT B)]
• Y=A+B
OR GATE
A B Y
0 0 .0
0 1 1
1 0 1
1 1 1
OR GATE USING NAND GATE
A B NOR(Y)
0 0 1
0 1 0
1 0 0
1 1 0
A Y
0 1
1 0
A B Y
0 0 0
0 1 1
1 0 1
1 1 1
A B Y
0 0 0
0 1 0
1 0 0
1 1 1
Unit_2_Boolean_algebra_and_Karnaugh_maps.pptx
Unit_2_Boolean_algebra_and_Karnaugh_maps.pptx
Unit_2_Boolean_algebra_and_Karnaugh_maps.pptx
Unit_2_Boolean_algebra_and_Karnaugh_maps.pptx
Unit_2_Boolean_algebra_and_Karnaugh_maps.pptx
Unit_2_Boolean_algebra_and_Karnaugh_maps.pptx
Unit_2_Boolean_algebra_and_Karnaugh_maps.pptx
Unit_2_Boolean_algebra_and_Karnaugh_maps.pptx
Unit_2_Boolean_algebra_and_Karnaugh_maps.pptx
Unit_2_Boolean_algebra_and_Karnaugh_maps.pptx
Unit_2_Boolean_algebra_and_Karnaugh_maps.pptx

Unit_2_Boolean_algebra_and_Karnaugh_maps.pptx

  • 1.
    Unit 2 Booleanalgebra and Karnaugh maps Boolean algebra rules and Boolean laws: Commutative, Associative, Distributive, AND, OR and Inversion laws, De Morgan’s theorem, Universal gates, Simplifications of Logic equations using Boolean algebra rules and Karnaugh map (up to 4 bit). Lab Session: - Binary to Gray Interconversion of Logic Gates
  • 2.
  • 16.
  • 17.
    A B ~A~B ~A.~B (A+B) ~(A+B) 0 0 1 1 1 0 1 0 1 1 0 0 1 0 1 0 0 1 0 1 0 1 1 0 0 0 1 0
  • 18.
    A B ~A~B ~A+~B (A.B) ~(A.B) 0 0 1 1 1 0 1 0 1 1 0 1 0 1 1 0 0 1 1 0 1 1 1 0 0 0 1 0
  • 22.
    y= A.B+C.D =SOP Y=(A+B).(C+D) = POS
  • 28.
  • 30.
    0 0 0 1 AB Y 0 0 0 0 1 0 1 0 0 1 1 1 0 0 1 1 A B Y=A.B
  • 31.
    3 INPUTS A,B AND C x yz Y IS THE OUTPUT Y=1 when inputs is >=4 Represent in kmap 0 00 1 01 3 11 2 10
  • 32.
    3 INPUTS A,B AND C Y IS THE OUTPUT Y=1 when of the inputs is >=4 Represent in kmap A B C Y 0 0 0 0 0 0 1 0 0 1 0 0 0 1 1 0 1 0 0 1 1 0 1 1 1 1 0 1 1 1 1 1 4 2 1
  • 33.
    3 INPUTS A,B AND C X & Y ARE THE OUTPUT X=1 when inputs ARE >=4 Y=1 when inputs ARE <=4 Represent in kmap INPUTS OUTPUTS A B C X Y 0 0 0 0 1 0 0 1 0 1 0 1 0 0 1 0 1 1 0 1 1 0 0 1 1 1 0 1 1 0 1 1 0 1 0 1 1 1 1 0 4 2 1
  • 34.
    FOR Y =A’+C’.B’ C’C AB C 0 1 A’B’ 00 1 1 A’B 01 1 1 AB 11 0 0 AB’ 10 1 0
  • 38.
    Y= C +AB Octet : 3 variables are eliminated Quad: 2 variables are eliminated Pair: 2 variables are eliminated BC…> 00 01 11 10 A 0 1 1 1 1 1 1
  • 40.
    Hence for 3-bitcode converters,
  • 41.
  • 43.
    G2 B2 B1B0 0001 11 10 0 ~B2 0 0 0 0 1 B2 1 1 1 1 G2= B2 G1= B2. ~B1 + ~B2.B1 = B2 XOR B1 G0= B1.~B0 + ~B1.BO =B1 XOR B0
  • 44.
    G1 B2 B1B0 0001 11 10 0 ~B2 0 0 1 1 1 B2 1 1 0 0 G2= B2 G1= B2. B1’ + B2’.B1 = B2 XOR B1 G0= B1.~B0 + ~B1.BO =B1 XOR B0 B1’B0’ B1’B0 B1B0 B1B0’
  • 45.
    G0 B2 B1B0 0001 11 10 0 ~B2 0 1 0 1 1 B2 0 1 0 1 G2= B2 G1= B2. ~B1 + ~B2.B1 = B2 XOR B1 G0= B1.B0’ + B1’.BO =B1 XOR B0
  • 46.
  • 48.
  • 49.
    Same i/p =0 output different i/p’s = 1 output • B2 b1 b0 1 1 0 binary ------ gray …………………………. 1 0 1 • G2 g1 g0
  • 50.
    Same i/p =0 output different i/p’s = 1 output • g2 g1 g0 1 1 0 gray------ bin …………………………. 1 0 0 • b2 b1 b0
  • 51.
    Unit 3: Introductionto Combinational Circuits Introduction to Combinational Circuits Basic Logic gates (NOT, OR, AND) & derived gates (NAND, NOR, EXOR) Symbol and truth table, half adder, full adder, Half subtractor, Four bit parallel adder. Multiplexer (4:1), demultiplexer (1:4) and their applications, Code converters - Decimal to binary, Hexadecimal to binary, BCD to decimal, Concept of Encoder & decoder. Lab Session: - To Study 4: 1 Multiplexer and 1 : Demultiplexer To Study nibble adder and Subtractor circuit
  • 52.
  • 61.
    • A isinput and Y is output • Y= ~A
  • 62.
    Y= A*B n= no.ofi/p’s 2^n input combinations in truth table
  • 63.
  • 64.
    • Y • Y=~(a.b) • Y=____ • Y =A*B = ~(A*B) ____ A*B
  • 65.
  • 66.
    Y=~a*b + a*~b OUTPUT=0if input contains even no.of 1’s OUTPUT=1 if input contains odd no.of 1’s • 0110 1101
  • 68.
  • 69.
    • 8 42 1 • 16 A B C D Y • 0 0 0 0 0 • 1 0 0 0 1 • 2 0 0 1 0 • 15 1 1 1 1
  • 71.
    A Y 0 1 10 A B Y(NAND) 0 0 1 0 0 1 1 0 1 1 1 0
  • 72.
    A B Y 00 0 0 1 0 1 0 0 1 1 1 AND GATE USING NAND GATE
  • 73.
    • Y= NOT[(NOTA).(NOT B)] • Y=A+B OR GATE A B Y 0 0 .0 0 1 1 1 0 1 1 1 1 OR GATE USING NAND GATE
  • 74.
    A B NOR(Y) 00 1 0 1 0 1 0 0 1 1 0 A Y 0 1 1 0
  • 75.
    A B Y 00 0 0 1 1 1 0 1 1 1 1
  • 76.
    A B Y 00 0 0 1 0 1 0 0 1 1 1