GATE | GATE CS 2020 | Question 29

A multiplexer is placed between a group of 32 registers and an accumulator to regulate data movement such that at any given point in time the content of only one register will move to the accumulator. The number of select lines needed for the multiplexer is _________ .

Note – This question was Numerical Type.
(A) 5
(B) 6
(C) 4
(D) 7


Answer: (A)

Explanation: Let there are ‘m’ select lines for a multiplexer, then it may have upto 2^m input lines.

Given that there are 32 input lines, so there must be ⌈log₂ (n)⌉ select lines = ⌈log₂ (32)⌉ = 5.

Option (A) is correct.

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