Transcend 4Gb/CF 133 [6/14] Kingston com fl ash

COMMITTED T O MEMORY

kingston.com/ ash

4.1 NOR FLASH MEMORY

NOR, named after the speci c data mapping technology (Not OR), is a high-speed Flash

technology. NOR Flash memor y provides high-speed random-access capabilities, being able

to read and write data in speci c locations in the memory without having to access the

memory in sequential mode. Unlike NAND Flash, NOR Flash allows the retrieval of data as

small as a single byte. NOR Flash excels in applications where data is randomly retrieved or

written. NOR is most often found built into cellular phones (to store the phone’s operating

system) and PDAs and is also used in computers to store the BIOS program that runs to

provide the start-up functionality

4.2 NAND FLASH MEMORY

NAND Flash was invented after NOR Flash, and is named after the speci c mapping

technology used for data (Not AND). NAND Flash memory reads and writes in high-speed,

sequential mode, handling data in small, block sizes (“pages”). NAND Flash can retrieve or

write data as single pages, but cannot retrieve individual bytes like NOR Flash.

NAND Flash memory is commonly found in solid-state hard drives, audio and video Flash

media devices, television set-top boxes, digital cameras, cell phones (for data storage) and

other devices where data is generally written or read sequentially.

For example, most digital cameras use NAND-Flash based digital  lm, as pictures are

usually taken and stored sequentially. NAND-Flash is also more e cient when pictures are

read back, as it transfers whole pages of data very quickly. As a sequential storage medium,

NAND Flash is ideal for data storage.

NAND Flash memory is less expensive than NOR Flash memory, and can accommodate

more storage capacity in the same die size.

Flash memory which stores a single bit per cell (e.g., a value of “0” or “1” per cell) is known

as Single-Level Cell (SLC) Flash.

* For operating system.

** For data storage.

NOR Flash

NAND Flash

High-speed Access Yes Yes

Page-Mode Data Access No Yes

Random Byte Level Access Yes No

Typical Uses Cell Phones*

BIOS Storage for PCs

Networking Device Memory

PDAs

Digital Cameras

Cell Phones**

MP3 players

Solid State Disk Drives

Set-Top Boxes

Industrial Storage