how USB flash drives works

The so-called "USB flash drive” is based on USB interface, flash memory chips as the storage medium, no need to drive a new generation of storage devices. USB flash drives, the emergence of a major breakthrough in the field of removable storage technology, its compact size, especially for portable, anytime, anywhere, and easily exchange information and data switching products is the ideal mobile office and data storage.

USB flash drives principle of using a standard USB interface, 32M ~ 256M capacity, maximum capacity of the existing 2G products, high-capacity data storage and exchange for all major operating systems and hardware platforms. Its low-end products in the market price is close to the floppy drive, and a lot of motherboard support boot from USB memory, more practical function. Overall, USB flash drives the Floppy incomparable advantages, mainly small size, fully functional, safe and reliable use. But there are not enough large capacity and can not extend higher prices, Win98 and some other operating system required to install the driver and other shortcomings.

    USB flash drives principle structure is basically composed of five parts: a USB port, the master chip, FLASH (flash memory) chip, PCB backplane, shell package. Among them, the main chip can be part of the company on their own R & D, while the most expensive part of the FLASH (flash memory) chips, may account for about 6/7 of the total amount of USB flash drives, and the general use of the brands currently on the market brand type range of

Basic working principle of the USB flash drives is relatively simple: the USB port is responsible for connecting computers, data input or output channel; main chip is responsible for the coordination and management of the various components and issued the action command, and the computer identified as U-disk " removable disk, USB flash drives principle of the "brain"; principle is basically the same flash chip and computer memory, save the data entity, which is characterized by the data is not lost after power failure, long-term preservation; the PCB backplane is responsible for provide the appropriate treatment data platform, and all components are connected together. USB flash drives operating system recognizes the user issued the action command after the data access, USB removable storage disk will contain several processing.

USB flash drives principle of storage

The formation of electron storage source and the drain current unidirectional conduction of semiconductor floating shed. The floating gate wrapped around the insulator layer of silicon oxide film. On top of it is to control the conduction current between the source and drain select / control gate. Data is 0 or 1 depending on whether electronic floating gate formed on the silicon substrate. Electronics is 0, no electronic 1.

Flash just like its name, delete the data before writing to initialize. Specifically, the electronics is derived from all the floating gate. Will soon be data owned by "1".

Write data only to 0 when the write data for the 1:00 to do nothing. Write 0:00, applying high voltage to the gate electrode and the drain, increasing the energy of electronic conduction between the source and drain. As a result, the electrons would break through the oxide film insulator, the floating gate.

Read data when applied to the gate electrode voltage, current greatly, current small as 0. Floating gate does not have the electronic state (data 1), the state of the gate electrode voltage is applied to the drain voltage is applied between the source and drain due to a large number of electronic mobile, it will generate electricity. Electronic state (data 0) in the floating gate, the electronic conduction in the channel will be reduced. Imposed after the gate electrode voltage floating-gate electronic absorption, it is difficult to have an impact on the channel.

The principle of the U-disk storage is: computer binary digital signal into the composite binary digital signal (the distribution, check stack instruction) to read and write to the USB chip adapter interface, the chip signal processing assigned to EPROM2, memory chips, the corresponding address is stored binary data, and data storage.