Memory operation terminology: Evaluate the statement: “A write operation may also be referred to as a ‘fetch’ operation.”
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AIncorrect
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BCorrect
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CCorrect for Harvard architecture only
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DDepends on cache policy
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EValid only during DMA bursts
Answer
Correct Answer: Incorrect
Explanation
Introduction / Context:Precision in memory-system vocabulary matters when reading datasheets, writing device drivers, or debugging bus cycles. “Fetch” has a specific meaning in computer architecture, and conflating it with “write” leads to misunderstandings about control signals and performance events.
Given Data / Assumptions:
- We refer to standard CPU and memory terminology.
- Bus signals differentiate read vs write (e.g., WE vs OE, or read/write lines).
- Instruction fetch is a canonical read transaction.
Concept / Approach:A write operation stores data into memory. A fetch operation is a read of an instruction (and, by extension, can mean any read of data/instruction when context is broad). On many CPUs, “instruction fetch” refers to the pipeline stage that reads opcodes from memory into the instruction cache or decode logic. Therefore, calling a write a “fetch” is incorrect; the terms denote different bus directions and control strobes.
Step-by-Step Solution:
Define write: transfer from CPU/peripheral to memory.Define fetch: memory to CPU read, typically for instructions.Conclude: write ≠ fetch.Verification / Alternative check:Examine timing diagrams: WE asserted for write cycles, OE asserted for read cycles; instruction fetches deassert WE. Performance counters also distinguish loads/stores and instruction fetches.
Why Other Options Are Wrong:
Correct/architecture/cache/DMA caveats: None change the fundamental directionality difference.Common Pitfalls:Using “fetch” generically for any memory access; in technical contexts, keep the distinction sharp.
Final Answer:Incorrect