Recognizing applications of digital multiplexers Which application correctly reflects a common, practical use of a digital multiplexer (data selector) in digital system design?
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Adata generation
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Bserial-to-parallel conversion
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Cparity checking
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Ddata selector
Answer
Correct Answer: data selector
Explanation
Introduction / Context:A multiplexer (MUX) routes one of many inputs to a single output based on select signals. It is often called a “data selector.” This role is ubiquitous in digital systems for bus sharing, input selection, and time-division multiplexed display driving.
Given Data / Assumptions:
- Multiplexer has multiple data inputs, select lines, and one output.
- At any instant exactly one input is connected through to the output.
- We are not describing arithmetic or error-detection functions.
Concept / Approach:The MUX’s primary use is selection of one input among many. Functions like serial-to-parallel conversion are typically performed by shift registers and demultiplexers, while parity checking uses XOR logic. Data generation suggests sources such as counters or LFSRs rather than a selector.
Step-by-Step Solution:
Identify multiplexer behavior: many-to-one selection.Match to application: “data selector.”Eliminate unrelated tasks (parity, format conversion, generation).Therefore, option (d) is correct.Verification / Alternative check:Look up 74HC151 (8-to-1 data selector) or similar: datasheets explicitly label these ICs as “multiplexer/data selector.”
Why Other Options Are Wrong:
- Data generation: multiplexers select existing data, they do not generate new data.
- Serial-to-parallel conversion: primarily uses shift registers and demultiplexers.
- Parity checking: uses XOR/XNOR networks, not a selector.
Common Pitfalls:Confusing multiplexers (many-to-one) with demultiplexers (one-to-many) and shift-register-based format converters.
Final Answer:data selector