Difficulty: Easy
Correct Answer: hexadecimal 1-of-16
Explanation:
Introduction / Context:
Decoders assert exactly one of many outputs based on a binary input code. When a truth table shows output lines numbered 0–15, it strongly suggests a 1-of-16 decode, commonly described as a “hexadecimal” (base-16) decoder because there are 16 distinct outputs for the 16 possible 4-bit input combinations.
Given Data / Assumptions:
Concept / Approach:
A 1-of-n decoder maps an n-ary selection from log2(n) binary inputs to n outputs. For 16 outputs, log2(16) = 4 inputs. Therefore a 1-of-16 decoder (often called hexadecimal) fits the 0–15 labeling perfectly.
Step-by-Step Solution:
Verification / Alternative check:
Typical parts (e.g., 74HC154) implement 4-to-16 decoding with outputs Y0..Y15, aligning with the 0–15 truth-table columns.
Why Other Options Are Wrong:
Dual octal outputs: would indicate two separate 1-of-8 sections, not a single 0–15 set.
Binary-to-hexadecimal: a converter/encoder term, not a one-hot decoder.
Hexadecimal-to-binary: describes an encoder, not a decoder with 16 distinct output lines.
Common Pitfalls:
Confusing decoders (one-hot outputs) with encoders/code converters (multi-bit outputs). Labeling 0–15 almost always implies 4-to-16 decoding.
Final Answer:
hexadecimal 1-of-16
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