Memory technologies – comparing EEPROM and EPROM Which of the following statements correctly highlights the key advantages of an EEPROM (Electrically Erasable Programmable Read-Only Memory) over an EPROM (Erasable PROM using ultraviolet light)?
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Athe EPROM can be erased with ultraviolet light in much less time than an EEPROM
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Bthe EEPROM can be erased and reprogrammed without removal from the circuit
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Cthe EEPROM has the ability to erase and reprogram individual words
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Dthe EEPROM can be erased and reprogrammed without removal from the circuit, and can erase and reprogram individual words
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EEEPROMs must always be removed from the board to be erased
Answer
Correct Answer: the EEPROM can be erased and reprogrammed without removal from the circuit, and can erase and reprogram individual words
Explanation
Introduction / Context:Nonvolatile memory families such as EPROM and EEPROM are widely used for firmware storage. Understanding how they are erased and programmed is crucial for in-circuit updates, field servicing, and device lifecycle management.
Given Data / Assumptions:
- EPROM requires ultraviolet (UV) light exposure through a quartz window to erase the entire chip.
- EEPROM supports electrical erase and program operations via standard supply pins.
- Both devices retain data without power (nonvolatile).
Concept / Approach:EPROM erasure is bulk-only and off-board: you must physically remove the device and expose it to UV for minutes. EEPROM allows electrical erasure in-system, typically byte-by-byte or word-by-word, enabling selective updates and field reprogramming without removing the IC.
Step-by-Step Solution:Identify erase method: EPROM uses UV light; EEPROM uses electrical signals on pins.Determine granularity: EPROM erases the whole array; EEPROM commonly supports byte/word erase and program.Infer maintenance benefit: EEPROM enables in-circuit, selective updates, minimizing downtime.
Verification / Alternative check:Datasheets state that EPROM needs UV erasure and EEPROM provides electrical erase/program functionality, often with byte-level granularity and write/erase endurance specifications.
Why Other Options Are Wrong:EPROM UV erasure is not “much less time” than EEPROM; EEPROM writes/erases electrically and quickly in-system.Stating only one EEPROM advantage (in-circuit or per-word) is incomplete; both apply.Claiming EEPROM must be removed is the opposite of its key benefit.
Common Pitfalls:Confusing EEPROM with flash; while both are electrically erasable, flash typically erases in sectors/blocks, whereas EEPROM commonly allows byte/word operations.
Final Answer:the EEPROM can be erased and reprogrammed without removal from the circuit, and can erase and reprogram individual words