Question

Which type of ROM supports erasing the contents using ultraviolet light and then reprogramming it ?

• A. PROM
• B. EPROM
• C. EEPROM
• D. DRAM

Answer 1

Answer:

B. EPROM

EPROM (Erasable Programmable Read-Only Memory)

• EPROM stands for Erasable Programmable Read-Only Memory. It is a type of non-volatile memory that retains its data even when the power supply is turned off.

• Erasing Mechanism: The contents of an EPROM can be erased by exposing the chip to intense ultraviolet (UV) light for a duration typically ranging from 15 to 30 minutes.

• Physical Structure: These chips are easily identifiable by a small, transparent quartz glass window located on the top of the package. This window allows the UV light to reach the internal silicon die to perform the erasure process.

• Reprogramming: After the UV light erases the existing data, the EPROM can be reprogrammed using an external device known as an EPROM programmer or PROM burner.

• Comparison with other ROM types:

  • PROM (Programmable ROM): Can be programmed only once using a specialized programmer.

  • EEPROM (Electrically Erasable Programmable ROM): Can be erased electrically without removing the chip from the circuit, making it more convenient than EPROM.

  • Flash Memory: A modern, high-speed variant of EEPROM that allows for block-level erasure and writing.

• Historical Context: Invented by Dov Frohman at Intel in 1971, EPROM was a revolutionary step in allowing developers to update firmware without discarding the hardware.