Flash memory gets its name because of its smart layout in such a manner that its section of memory cells in a single action or “Flash” is deleted. Both NOR and NAND flash memory were presented by Dr. Fujio Masuoka invented by Toshiba in 1984.The name ‘Flash’ was suggested because the erasure process is reminiscent of the memory contents of a flash of a camera, and his name was coined to express how much faster it could be extinguished in a flash. ” Dr. Masuoka presented the invention at the International Electron Devices Meeting (IEDM) held in San Jose, California, in 1984, and Intel recognizes the potential of the invention and introduction of the first commercial chip NOR Flash in 1988, with a long letter, and delete.
Flash memory is a form of non-volatile memory that can be electrically erased and rewrite, which they do not need to protect the data stored in the chip does care. In addition, flash memory offers fast read access and better shock resistance than hard disks. These characteristics explain the popularity of flash memory for applications such as storage on battery-powered devices.
Flash memory is in front of the EEPROM (electrically erasable programmable read-only) that allows multiple memory locations to be erased or overwritten in a programming operation. In contrast to a programmed EPROM (memory electrically programmable read-only), an EEPROM and deleted multiple times electrically. Normal EEPROM only allows one location at a time to delete or be written, which means that the flash can operate at higher speeds in force when the systems use reading and writing in various places at the same time.
is used with reference to the type of logic gate in each memory cell, Flash memory is built in two variants and designated NOR Flash and NAND Flash.
Flash memory stores one bit of information in a network of transistors, called “cells” but these flash memory known as multi-level cell devices, can be more than 1 bit per cell, depending on the amount of electron placed on the floating gate cell. Cell NOR flash memory device such as a semiconductor transistors, but it has two doors. The first is the control gate (CG) and the second is a floating gate (FG) insulated all around the plate or by an oxide layer. Since the FG is isolated by his shield oxide layer, electrons placed on it and catch data is stored within. In addition, NAND flash tunnel injection used for writing and tunnel release for erasing.
NOR Flash, ranging from Intel in 1988 with the special feature of the long delays in the write and erase and endurance of erase cycles is developed 10000-100000, for storing program code, which must often, as in Digital cameras and PDAs updated. Although later tickets than the cheaper NAND flash demand is moved, NOR Flash-based so far the source of all removable media.
Followed in 1989 as Samsung and Toshiba NAND flash memory with high density, low cost per bit then NOR Flash erase faster write times, but it only allows sequence data access, not random as NOR flash, NAND flash, which for mass storage devices such as memory cards. Smart Media was first NAND removable media and many others are originally MMC, Secure Digital, xD-Picture Card and Memory Stick. Flash memory is commonly used to hold control code such as the Basic Input / Output System (BIOS) in a computer. If the BIOS (rewritten) amended to flash memory in the block can be written instead of byte sizes, making it easier to update.
On the other hand, flash memory is not practical, Random Access Memory (RAM) as RAM needs addressable at the byte (not the block). It is used more than one hard drive as a RAM. Because of this unique individual, it is with specially designed file systems which extend writes used to delete the media and to deal longer NOR flash devices. Jffs had overtaken the first file system JFFS2. Then yaffs was published in 2003, which was specifically with NAND flash and JFFS2 updated to support NAND flash too. But in practice most follows old FAT file system for compatibility.
Although it may read or write one byte at a time in a random access mode, the limitation of flash memory, it has a “block” will be deleted at a time. From a freshly erased block, a byte can be programmed in that sentence. However, once a byte has been programmed, it can not be changed until the entire block is erased. In other words, Flash memory (NOR flash especially) random-access read and programming, but can not offer random-access rewrite or erase operations.
This effect is partially offset by a chip or firmware file system writes by counting the offset and dynamic reconfiguration of the blocks in the spread write operations between sectors or manuscript review and redesign of spare sectors in case of failure of the letter.
erode due to the wear of the insulating oxide layer around the charge storage mechanism, all types of flash memory after a certain number of erase capabilities of 100,000 to 1,000,000, but it can be viewed an unlimited number of times. Flash Card is easily rewritable memory and overwrites without warning with a high probability of data overwritten and lost.
Despite all these obvious advantages, may get worse due to system failure, battery failure, accidental deletion, formatting, power surges, faulty electronics, and corruption caused by hardware failure or software malfunction led to the following data is lost and damaged.
Flash memory data recovery is the process of recovering data from primary storage media when it can not be accessed normally. Flash Data Recovery is a flash memory file recovery service that restores deleted and damaged photos, even when a card is reformatted. This can result in physical harm or damage, the logical storage device. Data flash memory can also be recovered damages and over 90% of data loss can be recovered.