EEPROM is a live erasable programmable read-only memory. It is a memory chip with no data loss after power failure. EEPROM can erase existing information and reprogram it on a computer or on a dedicated device. Usually used for Plug and Play.

EEPROM (charged erasable programmable read-only memory) is a user-modifiable read-only memory (ROM), which can be erased and reprogrammed (rewritten) by higher than normal voltage. Unlike EPROM chips, EEPROM can be modified without having to be removed from the computer. In an EEPROM, the life of the EEPROM is an important design consideration because the computer can be programmed repeatedly when it is in use. EEPROM is a special form of flash memory that is typically used to erase and reprogram voltage from a personal computer

The writing process of EEPROM takes advantage of the tunnel effect that electrons with less energy than the energy barrier can cross the barrier to the other side. Quantum mechanics assumes that electrons fluctuate when the physical size is equal to the free path of the electron, which means that the object is small enough.

As far as the P n junction is concerned, when the impurity concentration of P and N reaches a certain level and the space charge is very small, the electrons will migrate due to the tunnel effect guide band. The range in which the energy of an electron is at an allowable level is called a band, the lower band is called a valence band, and the higher band is called a conduction band. When an electron reaches a higher conduction band, it can move freely between atoms, which is the current.

Due to the inconvenience of EPROM operation, the BIOS ROM chips on the motherboard are mostly EEPROM (Electrical Erasable Programmable ROM).

EEPROM erase does not need to use other devices, it uses electronic signals to modify its contents, and uses Byte as the smallest unit of modification, so it can write without washing out all the data, completely breaking away from the constraints of EPROM Eraser and the programmer.