ROM data retention characteristic ROM devices retain their stored data under which power condition?

Introduction / Context:
Read-only memories (ROM, PROM, EPROM, EEPROM/Flash) are nonvolatile, meaning they retain information without continuous power. This property distinguishes them from volatile memories like SRAM and DRAM, which lose data when power is removed (unless backed up).

Given Data / Assumptions:

• Nonvolatile memory is intended to preserve firmware/configuration across power cycles.
• ROM family includes factory-programmed (mask ROM), field-programmable (PROM/EPROM), and electrically erasable variants (EEPROM/Flash).

Concept / Approach:
The definition of nonvolatile is data retention with power removed. Hence, the key advantage of ROM-type devices is that they store code or constants even when the system is off, enabling bootstrapping and persistent configuration.

Step-by-Step Solution:
Identify ROM as nonvolatile storage.Nonvolatile → retains data without power.Therefore, data is retained when power is off.

Verification / Alternative check:
Device datasheets guarantee data retention over specified time/temperature with power removed (for EEPROM/Flash, often years to decades), confirming nonvolatility.

Why Other Options Are Wrong:

• “Power is on”: Trivially true, but the defining feature is retention with power off.
• “System is down”: Ambiguous wording; what matters is power at the device pins.
• “All of the above”: Overbroad; only “power is off” captures the defining trait.

Common Pitfalls:

• Confusing ROM with battery-backed RAM; both may retain data across outages, but by different means.
• Assuming all nonvolatile devices are infinitely durable; write/erase cycles and retention times are finite.

Final Answer:
Power is off