Mask ROM (MROM) data attribute: In a mask-programmed ROM, the stored data pattern is considered to be which of the following over the lifetime of the device?

Introduction / Context:
Mask ROM (MROM) devices are programmed during semiconductor fabrication using photolithographic masks. They are cost-effective at very high volumes but cannot be altered after manufacture. Selecting the correct memory type depends on whether the content must be field-updatable or fixed forever.

Given Data / Assumptions:

• MROM content is defined during wafer processing.
• No electrical erase or reprogram capabilities exist.
• Use cases include fixed firmware for mass-produced devices.

Concept / Approach:
Because the bit pattern is physically encoded in the silicon by masks, the data is effectively permanent for the life of the device. There is no refresh requirement, and data does not disappear when power is removed (nonvolatile). Any change requires a new mask set and fabrication run, not a field operation.

Step-by-Step Solution:

Verification / Alternative check:
Compare to PROM/EPROM/EEPROM/Flash: all are field-programmable to varying degrees; MROM is not. Datasheets and textbooks consistently call MROM content permanent.

Why Other Options Are Wrong:
Volatile: incorrect; MROM is nonvolatile. Erasable/Temporary/Battery-backed only: do not describe mask-defined, unchangeable content.

Common Pitfalls:
Assuming “ROM” always means erasable (e.g., EEPROM); only certain ROM types support electrical erasure.

Final Answer:
Permanent