Page 61 - computer science (868) class 11
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A' A'.B'.C
B'
C
A' A'.B.C' A'.B'.C + A'.B.C' + A.B'.C' + A.B.C
B
C'
A A.B'.C'
B'
C'
A A.B.C
B
C
Applications of the XOR gate:
• Used in half and full adders.
• Used in pseudo-random number generation.
2.7.7 XNOR Gate
The XNOR gate is a digital logical gate that produces 0 (low) as output for an odd number of 1 (high) as input. It
is pronounced as exclusive NOR gate. It is the complement of the XOR gate. An encircled dot sign ⊙ is used to
show the XNOR operation.
The symbol and truth table of the XNOR gate are given below.
A B A⊙B
A A⊙B
0 0 1
B
0 1 0
Symbol of XNOR gate
1 0 0
1 1 1 The Boolean expression of the two
variable XNOR gate is A'.B' + A.B.
Truth table of two variables XNOR gate
The logic circuit diagram of the two variables XNOR gate is as follows:
A A.B
B
A'.B' + A.B
A' A'.B'
B'
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Propositional Logic, Hardware Implementation, Arithmetic Operations 59

