EEPROM - Definition and Overview

An EEPROM (E²PROM), or Electrically-Erasable Programmable Read-Only Memory, is a non-volatile storage chip used in computers and other devices. Unlike an EPROM, an EEPROM can be programmed and erased multiple times electrically. It may be erased and reprogrammed only a certain number of times, ranging from 100,000 to 1,000,000, but it can be read an unlimited number of times. Flash memory is a later form of EEPROM. In the industry, there is a convention to reserve the term EEPROM to byte-wise writable memories compared to block-wise writable flash memories. EEPROM takes more die area than flash memory for the same capacity because each cell usually needs both a read and a write transistor where flash memory needs only one.