09-05-2012, 03:14 PM
Flash memory
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Introduction
We know various terms of memories uses in the computer depend upon our requirement. Using EEPROM we store the solid-state memory technologies of ROM, CACHE and BIOS, which are available in the chip forms. For data storage hard disk
Floppy disks and tapes are uses the magnetic storage technology. In this type of magnetic storage devices there are moving parts, so in this shape also they are big. Due to decreasing the size of storage devices there is need for reducing the size of memory. So, now days in the type of memories are available in the market. Flash memory is one of the storage devices available in the market.
A flash memory is a solid-state electronic memory, but instead of using like a RAM, we can use as a data storage hard disk. Now a days flash memory is using for data storage in the digital cameras and cell phones, MP3 players, PDA. First future of flash memory is small size and second future is it has not contained any mechanical devices so the problem with this device is less.
Flash memory also working like an EEPROM chip. There is no difference between EEPROM and flash memory in case of using their technology. In case of changing the data in EEPROM, we uses special PROM burner but in flash memory we uses software programs to change the memory.
Like not RAM losses data when computer offs, flash memory like as bios chip and again we can change by using software it has a future like we can operate more than one byte but EEPROM can operate only on one byte. So, it can replace in the case of hard disk.
Flash Memory
Flash Memory is a solid State non-volatile Memory device which is used to store the information in 0’s and 1’s like as Ram.
Memory is capable of retaining digit information under certain conditions.
This retained material might be operational code or data files, or a combination of two.
The ideal memory subsystem optimizes density, preserves critical material in a nonvolatile condition, is easy to program and reprogram, can be read fast, and is cost-effective for the
Application. Some of memory technologies meet one or more of these requirements very well, but offsetting limitations can prevent the product from becoming a genuine solution, especially in newer applications.
Technical over view of Flash Memory
Flash memory is not a non-volatile memory using NOR technology, which allows the user to electrically program and erase information. Intel flash memory uses memory cells similar to an EPROM, but with a much thinner, precisely grown oxide between the floating gate and the source. Flash programming occurs when electrons are placed on the floating gate. The charge is stored on the floating gate, with the oxide layer allowing the cell to be electrically erased through the source. Intel flash memory is extremely reliable non-volatile memory architecture.
Programming and Erasing
Programming on Intel flash is most commonly done in a byte or word wide mode. However, several devices provide 32 byte write buffers. These buffers allow data to be queued in advance for up to 2 microns effective byte programming speeds. Eraser of the flash device is done through a block erase command, and the
Completion time is dependent upon the block size and technology. Functions, such as program-suspend, program-resume, erase-suspend and erase-resume, allow the device to pause and read data, and then resume the previous operations.
Software enabled features
Intel flash memory provides several enabled features that optimize code, increase system performance and help to protect the integrity of the information stored on the device.
The Common Flash Interface (CFI) and Status registers are features used for code optimization. The CFI query register contains non-alterable data about the component, such as block sizes, density, X8/X16 and electrical specifications. Think of these features as a data book on a chip that allows the software to adapt to several different devices by passing variable from the CFI registers. Additionally the status register is used to query the operating status of the device during programming, erase and suspend modes.