Read/write memory identification: Which of the following is a standard example of read/write (random-access, user-alterable during normal operation) semiconductor memory?
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APROM
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BEEPROM
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CRAM
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DMROM
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EFlash ROM
Answer
Correct Answer: RAM
Explanation
Introduction / Context:Semiconductor memories are commonly grouped into read/write memories and read-mostly or read-only memories. Read/write memory typically refers to RAM used as working storage in computers and embedded systems. Recognizing which technologies are volatile, nonvolatile, erasable, or one-time programmable is basic to memory selection and system design.
Given Data / Assumptions:
- Read/write memory here means memory freely writable and readable during normal system operation.
- Standard device categories: RAM, PROM, EEPROM, Mask ROM (MROM), Flash.
- General textbook conventions are assumed.
Concept / Approach:RAM (Random-Access Memory) is the canonical read/write memory: the processor can store and retrieve data at any time during normal operation. PROM and MROM are programmed once (PROM by the user with a programmer; MROM at the factory). EEPROM and Flash are nonvolatile and electrically erasable, but not typically written as frequently as RAM during normal program execution; their writes are slower and follow erase-program cycles.
Step-by-Step Solution:
Define the class: read/write ≈ operationally alterable, random access, frequent updates.Classify options: RAM fits; PROM/MROM are not repeatedly writable; EEPROM/Flash are rewritable but not used as the primary read/write working store.Select RAM as the best, standard example.Verification / Alternative check:Typical architectures: program/data execute in RAM; firmware or configuration data reside in nonvolatile memories (Flash/EEPROM) updated infrequently. This separation confirms RAM as the intended answer.
Why Other Options Are Wrong:PROM and MROM are not rewritable in-system. EEPROM and Flash are rewritable but slow, endurance-limited, and usually not used for general-purpose working memory.
Common Pitfalls:Equating “electrically erasable” with the same role as RAM; although writable, EEPROM/Flash have different performance and usage models.
Final Answer:RAM