FLASH memories are being used widely as non-volatile memory for the purpose of storing large amount of data in a small foot-print. Flash memory was invented by Dr. Fujio Mansuoka while working for Toshiba in 1980. According to Toshiba, the name "flash" was suggested by Dr. Masuoka's colleague, Mr. Shoji Ariizumi, because the erasure process of the memory contents reminded him of a flash of a camera.Flash memory is a form of EEPROM (Electrically Erasable Programmable Read-Only Memory) that allows multiple memory locations to be erased or written in one programming operation. In other terms, it is a form of rewritable memory chip that, unlike a RAM (Random Access Memory) chip, power supply is not required to hold the contents. It is commonly used in memory cards for computers, USB flash drives, MP3 players, digital cameras, mobile phones and many other electronic embedded products. The FLASH memory has certain advantages as compared to the other non-volatile memories such as EEPROM or the hard drives. FLASH memories
- offer better (faster) read access time as compared to the EEPROM.
- offer better kinetic shock resistance than the hard disks.
- when FLASH memory is packaged in a "memory card", it is enormously durable, can withstand harsh environmental conditions
FLASH memories are of two types - "NAND FLASH" and "NOR FLASH". Both types has certain advantages over the other. The following table and the picture depicts a comparison between these two types of FLASH memory.
