Difficulty: Easy
Correct Answer: Correct
Explanation:
Introduction / Context:
Understanding how nonvolatile memories store information helps explain retention and endurance specs. EEPROMs and Flash use a floating-gate transistor to store charge, which alters the cell’s threshold voltage and thereby encodes a bit. The statement summarizes this behavior and typical retention times.
Given Data / Assumptions:
Concept / Approach:
The floating gate is insulated by oxide, so injected electrons remain trapped for long periods. Reading senses the threshold shift; erasing/programming adds or removes charge via tunneling. Unless an erase/program pulse or high-temperature stress accelerates leakage, charge remains for many years, aligning with datasheet retention specs.
Step-by-Step Solution:
Verification / Alternative check:
Vendor specifications specify retention at temperature (for example, 10 years at 85 C or longer at room temperature). Field-programmable microcontrollers store firmware in Flash for device lifetimes without continuous power.
Why Other Options Are Wrong:
The mechanism is common to EEPROM and Flash; continuous power is not required for charge retention; claiming hours contradicts practice.
Common Pitfalls:
Confusing retention (data persistence) with endurance (cycle count). Retention is long even as endurance limits write/erase frequency.
Final Answer:
Correct
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