ITPEC FE Morning October 2022 Question 14

Mask ROM — a memory device programmed at the factory with no write capability.

Key distinction between ROM types:

• •Mask ROM — written once during manufacturing using a photolithographic mask; read-only after that
• •PROM — written once by the user (one-time programmable)
• •EPROM — erasable with UV light, then rewritable
• •EEPROM — electrically erasable and rewritable
• •Flash memory — a type of EEPROM, erasable in blocks

Why not others:
- (a) DRAM — volatile read/write memory used as main memory; requires constant refreshing
- (b) Flash memory — non-volatile but supports both read and write operations
- (d) SRAM — volatile read/write memory used for cache; faster than DRAM but more expensive

Key rule: "Stores programs in factories" + "only read" = Mask ROM. The word "mask" refers to the photolithographic mask used during chip fabrication.

AI-generated — may contain errors