The computer converts the binary digital signal into a composite binary digital signal (adding instructions such as allocation, check and stack) and reads it to the USB chip adapter interface. The chip processes the signal and stores the binary data at the corresponding address assigned to the EEPROM memory chip, thus realizing data storage. The control principle of EEPROM data storage is that the voltage of the gate transistor is controlled by the voltage, and the junction capacitance of the gate transistor can store the voltage value for a long time. The main reason for saving data after power failure is that floating gate and selection gate are added to the original transistor. A floating gate for storing electrons is formed on a semiconductor with unidirectional current conduction between the source and the drain. The floating gate is wrapped by a silicon oxide film insulator. Above it is a select/control gate that controls the conduction current between the source and the drain. Whether the data is 0 or 1 depends on whether there are electrons in the floating gate formed on the silicon substrate. One electron is 0, and none is 1. Flash memory, as its name implies, deletes data for initialization before writing. Specifically, electrons are extracted from all floating gates. Some data will return to "1". Write only when the data is 0, and do nothing when the data is 1 When writing 0, a high voltage is applied to the gate electrode and the drain electrode, increasing the electron energy conducted between the source electrode and the drain electrode. In this way, electrons will break through the oxide film insulator and enter the floating gate. When reading data, a certain voltage is applied to the gate electrode, the current is 1, and the current is 0 if it is small. When there are no electrons in the floating gate (data is 1), when a voltage is applied to the gate electrode, a voltage is applied to the drain, and a current will be generated between the source and the drain due to the movement of a large number of electrons. But when there are electrons in the floating gate (data is 0), the electrons conducted in the channel will decrease. Because the voltage applied to the gate electrode is absorbed by the floating gate electrons, it is difficult to affect the channel.
In July 2002, Netac's "Flash electronic external storage method and device for data processing system" (patent number: ZL 99 1 17225.6) was officially authorized by China National Intellectual Property Administration. This patent fills the gap of invention patent in the field of computer storage in China for 20 years.