EEPROM: Electrically Erasable Programmable Read-Only Memory

EEPROM Full Form in Computer

Non-volatile ROMs like EEPROMs allow for the programming and erasing of single bytes of data. Due to this, EEPROM chips are also referred to as byte erasable chips. Small bits of data are typically stored in EEPROM by computers and other electronic devices. EEPROM, short for electrically erasable programmable read-only memory, was created by scientists at Hughes Aircraft and Intel in the late 1970s and early 1980s to replace EPROM and PROM memory. The EPROM technology was widely utilized before EEPROM. If EPROM memory chips were exposed to UV light, they could be programmed and then wiped. However, electronic erasure of the chips was not possible. EEPROM technology was developed to meet these difficulties. EEPROM can be deleted and programmed electrically based on the current EPROM structure. The typical lifespan of an EEPROM chip is 10,000–100,000 write cycles, which is significantly longer than the write cycles of an EPROM chip.

Electrically Erasable Programmable Read-Only Memory is known as EEPROM. For use in microcontrollers for smart cards, remote keyless entry systems, and other electronic or computational devices, EEPROM is a type of non-volatile memory. It is used to hold very small amounts of data and enables the deletion and reprogramming of single bytes.

Several businesses and groups carried out research, created inventions, and worked on developing electrically reprogrammable non-volatile memory in the early 1970s. The first study report was presented in 1971 by Yasuo Tarui, Yutaka Hayashi, and Kiyoko Nagai from the Electrotechnical Laboratory, a national research organization in Japan, at the 3rd Conference on Solid State Devices, Tokyo. They created an EEPROM chip in 1972 and carried on with this research for more than ten years. Later publications and patents have often mentioned these papers. George Perlegos and his colleagues at Intel developed a number of innovations to enhance the tunneling E2PROM technology between 1976 and 1978. A 16K (2K word 8) bit Intel 2816 chip with a thin silicon dioxide layer, less than 200, was created in 1978. This structure was made known to the public in 1980 under the name FLOTOX, or floating gate tunnel oxide. Up to 10,000 times more reliable erase/write cycles per byte were achieved with the FLOTOX structure. With the exception of 5V read operations, this device needed an additional 20–22V VPP bias voltage supply to erase bytes. Perlego's and two other members of Intel's staff left the company in 1981 to found Seeq Technology, which used on-device charge pumps to generate the high voltages required for E2PROM programming.

EEPROM Memory Types

There are two different kinds of EEPROM memory chip:

  1. Serial EEPROM: Serial EEPROM chips are denser than parallel EEPROM chips because they can fit inside a tiny eight-pin package. Additionally, serial chips cost less money. The disadvantage is that data is conveyed slowly and serially. Their operations are also more complicated.
  2. Parallel EEPROM: Both EPROM and flash memory devices are compatible with the parallel EEPROM chip. Compared to the serial EEPROM technology, its data transfer method is quicker and more dependable. Its size, density, and price are all increased by the fact that it has a higher pin count. Due to these factors, flash memory or serial EEPROM is more commonly used than parallel EEPROM.

Pros and Cons

The ability to be repeatedly reprogrammed is one of EEPROM's main benefits. Non-volatile storage media allow for byte-by-byte erasure of the data they contain. Additionally, because the erase occurs electrically, it happens almost instantly. Unlike EPROM chips, EEPROM chips can be reprogrammed without being taken out of the computer. Despite these benefits, EEPROM has certain drawbacks. It is more costly and has a shorter data retention period than PROM and EPROM. Furthermore, systems using serial EEPROM chips may suffer from high costs. Additionally, EEPROM read/write cycles take longer than RAM cycles. It's crucial to utilize the information kept in EEPROM in a method that doesn't hinder system operations in order to account for this. Last but not least, various voltages are needed to read, write, and delete data from or onto EEPROM. A separate high-voltage source is no longer necessary, thanks to the incorporation of a high-voltage source in newer EEPROM chips. Because these chips may operate off of a single source, the design is made simpler and less expensive. EEPROM memory is utilized widely despite its disadvantages, particularly in situations where the number of read/write cycles is constrained.