Difficulty: Easy
Correct Answer: The refresh cycle keeps the charge on the capacitor cells.
Explanation:
Introduction / Context:
Unlike SRAM, DRAM uses capacitors to store bits. Due to leakage, the stored charge decays, so periodic refresh is required to maintain data validity. Understanding what refresh actually does prevents misconceptions about DRAM behavior.
Given Data / Assumptions:
Concept / Approach:
During refresh, the sense amplifiers detect the small residual charge and then restore a full charge to represent a 1 (or zero level as required), effectively “recharging” each capacitor so that data persists for the specified retention time.
Step-by-Step Solution:
Verification / Alternative check:
DRAM timing diagrams show refresh cycles that access rows even without CPU requests, ensuring each row is periodically restored.
Why Other Options Are Wrong:
Common Pitfalls:
Final Answer:
The refresh cycle keeps the charge on the capacitor cells.
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