Acronym check in digital logic: “LUT” correctly expands to “look-up table.” Indicate whether this terminology usage is accurate in FPGA/CPLD contexts.
Digital Electronics
Programmable Logic Device
Difficulty: Easy
Choose an option
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ACorrect
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BIncorrect
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CLegacy definition; modern usage differs
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DApplies only to ASIC standard cells
Answer
Correct Answer: Correct
Explanation
Introduction / Context: LUTs are the basic logic resources in many FPGA architectures and also appear conceptually in CPLDs and synthesis discussions. This question checks recognition of a core acronym encountered in vendor literature and academic texts.
Given Data / Assumptions:
- LUT is a small memory that maps input address bits to a stored output bit pattern.
- Vendors use “LUT” consistently to mean “look-up table.”
- The term is not limited to any one vendor or family.
Concept / Approach: A look-up table implements combinational functions by storing truth-table entries. For n inputs, the LUT stores 2^n output values. Synthesis tools map boolean logic to LUTs in FPGAs, making this acronym central to modern digital design.
Step-by-Step Solution:
Recall LUT definition → memory-based truth-table element.Map to term expansion → LUT = look-up table.Conclude the statement correctly reflects industry usage.Verification / Alternative check:
Check any FPGA architecture overview; LUT terminology is universal.Why Other Options Are Wrong:
Incorrect: Would deny a standard expansion.Legacy definition; modern usage differs: The meaning has remained consistent.Applies only to ASIC standard cells: LUTs are FPGA-centric, not ASIC standard-cell primitives.Common Pitfalls:
Confusing LUT with RAM blocks or ROM macros; LUTs are tiny and used for arbitrary logic mapping.Final Answer:
Correct