EEPROM

EEPROM (also written E2PROM and pronounced "e-e-prom," "double-e prom," "e-squared," or simply "e-prom") stands for Electrically Erasable Programmable Read-Only Memory and is a type of non-volatile memory used in computers and other electronic devices to store small amounts of data that must be saved when power is removed, e.g., calibration tables or device configuration.

When larger amounts of static data are to be stored (such as in USB flash drives) a specific type of EEPROM such as flash memory is more economical than traditional EEPROM devices. EEPROMs are realized as arrays of floating-gate transistors.

EEPROM is user-modifiable read-only memory (ROM) that can be erased and reprogrammed (written to) repeatedly through the application of higher than normal electrical voltage generated externally or internally in the case of modern EEPROMs. EPROM usually must be removed from the device for erasing and programming, whereas EEPROMs can be programmed and erased in-circuit. Originally, EEPROMs were limited to single byte operations which made them slower, but modern EEPROMs allow multi-byte page operations. It also has a limited life - that is, the number of times it could be reprogrammed was limited to tens or hundreds of thousands of times. That limitation has been extended to a million write operations in modern EEPROMs. In an EEPROM that is frequently reprogrammed while the computer is in use, the life of the EEPROM can be an important design consideration. It is for this reason that EEPROMs were used for configuration information, rather than random access memory.

Read more about EEPROMHistory, Functions of EEPROM, Failure Modes, Related Types, EEPROM Manufacturers

Other articles related to "eeprom, eeproms":

Elektronika MK-52 - Saving To EEPROM
... a program to volatile memory with the intention of saving this program to EEPROM memory, the EEPROM program space to be saved to must be cleared first, as performing the clearing operation clears the ... When clearing, reading or writing to the EEPROM memory, the 'address' and 'range' are specified in the form of a six-digit number, preceded by a non-zero number (which is ignored) in ...
EEPROM Manufacturers
... National Semiconductor (no longer makes standalone EEproms) ON Semiconductor Renesas Technology ROHM Samsung Electronics STMicroelectronics Seiko Instruments ...
Serial Presence Detect - Stored Information
... require certain parameters to be placed in the lower 128 bytes of an EEPROM located on the memory module ... The SPD EEPROM is accessed using SMBus, a variant of the I²C protocol ... The EEPROM shares ground pins with the RAM, has its own power pin, and has three additional pins (SA0–2) to identify the slot, which are used to assign the EEPROM ...
Serial Presence Detect - Reading and Writing SPD Information
... manufacturers write the SPD information to the EEPROM on the module ... It requires SMBus controller support in the kernel, the EEPROM kernel driver, and also that the SPD EEPROMs are connected to the SMBus ... reading and writing of SPD information is done by accessing the memory's EEPROM directly with eeprom programmer hardware and software ...
I²C - Design - Messaging Example: 24c32 EEPROM
... One specific example is the 24c32 type EEPROM, which uses two request bytes that are called Address High and Address Low ... Accordingly, these EEPROMs aren't usable by pure SMBus hosts, which only support single byte commands or addresses.) These bytes are used to address bytes within the 32 kbit (4 kB) supported ... Writing and reading data to these EEPROMs uses a simple protocol the address is written, and then data is transferred until the end of the message ...