FLASH MEMORY:-

• Flash memory is a non-volatile memory. That can be electrically erased and reprogrammed.

• It was developed from EEPROM (electrically erasable programmable read-only memory).

• Flash memory is a new memory technology that allowed stores data to be saved when the memory device was disconnected from its power sources.

• Flash memory is often used to hold control code such as the basic input/output system (BIOS) in a personal computer. When BIOS needs to be changed (rewritten), the flash memory can be written to in block (rather than byte) sizes, making it easy to update. On the other hand, flash memory is not useful as random access memory (RAM) because RAM needs to be addressable at the byte (not the block) level.

HISTORY:-

•  Flash memory was invented dr. fujio masuoka  while working for tosibha in 1980.

• Intel corporation introduced the first commercial nor type flash chip in 1988.

• Tosibha announced nand flash at the 1987 international electron device meeting.

INTERNAL STRUCTURE OF FLASH MEMORY

TYPES OF FLASH MEMORY:-

1.NOR FLASH:-

• —  NOR flash memory was first introduced by Intel in   1988.

•        Developed to replace read only memory

•        NOR flash is more expensive and takes longer to erase   and write new data.

•        NOR is most often used in mobile phones.

•        Can access any memory cell

•        Slow sequential access

• —

2.NAND FLASH

• —NAND flash was introduced by Toshiba in 1989.

• Developed to replace hard disks.

• NAND has significantly higher storage capacity than NOR.

• It has found a market in devices to 

• —MP3 players, digital cameras and USB

• —Can only access pages

• —Faster sequential access

•  which large files are frequently

• uploaded and replaced.

• drives use NAND flash

MANUFACTURERS OF FLASH:-

USES OF FLASH MEMORY

• Flash memory generally used in computers, television, set-up box, cell phone, digital cameras, mp3 players, global position system.

• We used the flash memory to store our data reprogrammed data.

• Flash memory is also used in much industrial applications.

ADVANTAGE OF FLASH MEMORY:-

• Flash memory is very durable and portable devices which we use every where easily.

• Flash memory is immersion in water.

• We can store much and more data in flash memory.

• We can read and erase our data easily.

LIMITATION / DISADVANTAGE OF FLASH:-

• —Both NAND/NOR memory has limited  number of programming/erasure cycles.

• About 100,000 cycles is a typical number, even though cells with higher cycle numbers can be designed.

• Virus can easily transfer in flash memory.—

• When flash memory is crash then data is lost.

FUTURE OF FLASH MEMORY:-

•     Continues to be among the most aggressively scaled electronic technologies   Memory cell size minimum of 20 nm expected to be met in 2010 May be replaced by Phase-Change RAM or other emerging technologies.

•       In the future size of flash memory cell is decrease and the capacity is increase.