Flash memory has become a powerful and cost-effective solid-state storage technology widely
used in mobile electronics devices and other consumer applications. Two major forms of Flash
memory, NAND Flash and NOR Flash, have emerged as the dominant varieties of non-volatile
semiconductor memories utilized in portable electronics devices. NAND Flash, which was
designed with a very small cell size to enable a low cost-per-bit of stored data, has been used
primarily as a high-density data storage medium for consumer devices such as digital still
cameras and USB solid-state disk drives. NOR Flash has typically been used for code storage
and direct execution in portable electronics devices, such as cellular phones and PDAs.