Read-only memory is a semiconductor storage medium permanently programmed with data during manufacturing or initial setup. It holds essential firmware, bootloaders, and lookup tables that must survive power cycles and remain protected from accidental overwrites. While early versions were hard-wired at the factory, later variants allow erasure and reprogramming, though the system treats them as static during normal operation.
The microcontroller is failing to boot because the masked ROM has a corrupted sector.
When engineers say a board has a bad ROM, they usually mean the flash chip holding the firmware, even though it is technically reprogrammable.
Also heard as
- read-only memory
Related terms
EEPROM
Electrically erasable programmable read-only memory is a non-volatile storage chip.
EPROM
An erasable programmable read-only memory is a non-volatile chip that can be wiped with ultraviolet light.
PROM
A type of memory chip that is programmed once by blowing internal fuses.
Flash memory
An electronic non-volatile computer storage medium that can be electrically erased and reprogrammed.
NVM
Computer storage that retains its data when electrical power is removed.