Basic logic function: a decoder translates which type of information into which form in digital systems?
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Anoncoded information into coded form
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Bcoded information into noncoded form
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CHIGHs to LOWs
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DLOWs to HIGHs
Answer
Correct Answer: coded information into noncoded form
Explanation
Introduction / Context:Decoders are core building blocks in digital systems. They interpret a compact binary code and assert exactly one of many outputs, enabling address selection, display driving, memory chip enables, and instruction decoding in CPUs.
Given Data / Assumptions:
- Inputs are a coded (binary) set of lines, e.g., n bits.
- Outputs are noncoded, typically a 1-of-2^n set of lines.
- Active-HIGH or active-LOW conventions may be used, but the mapping is one-hot.
Concept / Approach:Decoding expands compact coded information into explicit, mutually exclusive selections. For example, a 3-to-8 decoder uses 3 binary inputs to select 1 of 8 outputs. This “noncoded” set clearly identifies a single choice without further interpretation.
Step-by-Step Solution:Consider inputs ABC (binary code).The decoder asserts only the output line corresponding to the binary value of ABC.Thus, coded information (ABC) becomes a noncoded, one-hot output vector.
Verification / Alternative check:Seven-segment display drivers and memory address decoders are everyday examples; each input code turns on exactly one segment pattern or one memory bank enable line (with optional strobing or enable pins).
Why Other Options Are Wrong:
- Noncoded to coded describes an encoder, the inverse device.
- “HIGHs to LOWs” or “LOWs to HIGHs” oversimplify logic level inversion and do not capture decoding’s mapping function.
Common Pitfalls:
- Forgetting enable inputs; without proper enable the decoder may tri-state or force all outputs inactive.
- Not accounting for active-LOW outputs (bubble notation) when wiring external logic.
Final Answer:coded information into noncoded form