An EEPROM, 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.
Alternate definition: An acronym for Electrically Erasable PROM, or Electrically Erasable Programmable Read-Only Memory. An EEPROM memory cell is physically larger than an EPROM cell but offers the advantage of being erased electrically without the added expense and trouble of a special UV eraser requirement. Also, an extra advantage of this type device is that EEPROM devices can be erased, even in much lower cost plastic packaging.
