Question

Which gates are ideal for checking the parity bits?

(a) AND

(b) NAND

(c) EX-OR

(d) EX-NOR

The question was posed to me during an online exam.

I'd like to ask this question from Parity Generators/Checkers topic in section Combinational Circuits of Digital Circuits

Answer 1

Right choice is (c) EX-OR

Explanation: Exclusive-OR gates are ideal for checking the parity of a binary number because they produce an output when the input has an odd number of 1’s. Therefore, an even-parity input to an EX-OR gate produces a low output, while an odd parity input produces a high output. While, in case of AND, it produces high output when all inputs are 1 else low. Whereas, NAND, does the opposite, by producing low output when all inputs are 1 else high.