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Short note: Ex-OR and Ex-NOR gate

Short answer

Ex-OR (XOR) outputs 1 when inputs differ (A≠B), given by A⊕B = A B' + A' B. Ex-NOR (XNOR) is its complement, outputting 1 when inputs are equal (A=B), used in comparators. XOR is used in half adders, parity generators.

Write a short note on Ex-OR and Ex-NOR gate.

Ex-OR (XOR) gate. It gives output 1 when its two inputs are different (odd number of 1s), and 0 when they are equal.

Y=A⊕B=ABˉ+AˉBY=A\oplus B=A\bar B+\bar AB

Ex-NOR (XNOR) gate. It is the complement of XOR. Output is 1 when the inputs are equal.

Y=A⊕B‾=AB+AˉBˉY=\overline{A\oplus B}=AB+\bar A\bar B
ABXORXNOR
0001
0110
1010
1101
 A --|=\\
     |  )>-- A xor B        XNOR: same, with a bubble
 B --|=//                     (small circle) at the output

Applications:

  • XOR: half adder (sum =A⊕B=A\oplus B), binary adders/subtractors, parity generators and checkers, controlled inverter, binary-to-Gray code conversion.
  • XNOR: equality (comparator) circuits, which give 1 when two bits are the same.

✓ Answer checked by Claude Opus 5.5 (high effort)

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