A multiplexer is placed between a group of 32 registers and an accumulator to…
2020
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 _________ .
Answer: 5 — Short answer: 5 select lines. Why this is correct: A multiplexer with n select lines can choose between 2^n input lines. To select one register out of 32, we…
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Correct answer: 5
Short answer: 5 select lines.
Why this is correct: A multiplexer with n select lines can choose between 2^n input lines. To select one register out of 32, we need 2^n = 32, so n = log2(32) = 5.
Step 1: Recognize the relationship: n select lines → 2^n inputs.
Step 2: Set 2^n = 32 and solve: n = log2(32) = 5.
Note: If the number of registers were not an exact power of two, use n = ceil(log2(number of registers)).