Flash memory

flashNANDFlash ROMflash storageNAND flash memoryNOR flashNAND Flashflash RAMflash memoriesflash media
Flash memory is an electronic (solid-state) non-volatile computer memory storage medium that can be electrically erased and reprogrammed.wikipedia
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Electric field

electricelectrostatic fieldelectrical field
When the FG is charged with electrons, this charge screens the electric field from the CG, thus, increasing the threshold voltage (V T1 ) of the cell.

Threshold voltage

gate voltagelow threshold voltagepinch-off voltage
When the FG is charged with electrons, this charge screens the electric field from the CG, thus, increasing the threshold voltage (V T1 ) of the cell.

Field electron emission

field emissionFowler–Nordheim tunnelingfield emitters
The process of moving electrons from the control gate and into the floating gate is called Fowler–Nordheim tunneling, and it fundamentally changes the characteristics of the cell by increasing the MOSFET's threshold voltage.

Boost converter

(boost) DC-DC converterboostboost (step-up) converter
Since boost converters are inherently more efficient than charge pumps, researchers developing low-power SSDs have proposed returning to the dual Vcc/Vpp supply voltages used on all the early flash chips, driving the high Vpp voltage for all flash chips in a SSD with a single shared external boost converter.

Low-power electronics

low-powerlow powerULP
Since boost converters are inherently more efficient than charge pumps, researchers developing low-power SSDs have proposed returning to the dual Vcc/Vpp supply voltages used on all the early flash chips, driving the high Vpp voltage for all flash chips in a SSD with a single shared external boost converter.

USB

USB 2.0Universal Serial BusMicro USB
NAND flash memory forms the core of the removable USB storage devices known as USB flash drives, as well as most memory card formats and solid-state drives available today.

Silicon nitride

NieriteSi 3 N 4 nitride
V-NAND uses a charge trap flash geometry (which was commercially introduced in 2002 by AMD and Fujitsu) that stores charge on an embedded silicon nitride film.

Nibble

nybblehalf-byte4 bits
For example, a nibble value may be erased to 1111, then written as 1110.

YAFFS

YAFFS2Yaffs1
Some file systems designed for flash devices make use of this rewrite capability, for example Yaffs1, to represent sector metadata.

Sun Microsystems

SunSun Microsystems, Inc.Sun workstation
Micron Technology and Sun Microsystems announced an SLC NAND flash memory chip rated for 1,000,000 P/E cycles on 17 December 2008.

Bad sector

bad blockbad block re-mappingbad sectors
Another approach is to perform write verification and remapping to spare sectors in case of write failure, a technique called bad block management (BBM).

Router (computing)

routerroutersnetwork router
This limitation is meaningless for 'read-only' applications such as thin clients and routers, which are programmed only once or at most a few times during their lifetimes.

Ball grid array

BGAMicro-FCBGATFBGA
Most flash ICs come in ball grid array (BGA) packages, and even the ones that do not are often mounted on a PCB next to other BGA packages.

Rework (electronics)

reworkrework stationreflow
After PCB Assembly, boards with BGA packages are often X-rayed to see if the balls are making proper connections to the proper pad, or if the BGA needs rework.

Bus (computing)

buscomputer busdata bus
The low-level interface to flash memory chips differs from those of other memory types such as DRAM, ROM, and EEPROM, which support bit-alterability (both zero to one and one to zero) and random access via externally accessible address buses.

Device driver

driverdriversdevice drivers
In older NOR devices not supporting bad block management, the software or device driver controlling the memory chip must correct for blocks that wear out, or the device will cease to work reliably.

Error correction code

error-correcting codeerror correcting codeECC
If the flash controller does not intervene in time, however, a read disturb error will occur with possible data loss if the errors are too numerous to correct with an error-correcting code. Associated with each page are a few bytes (typically 1/32 of the data size) that can be used for storage of an error correcting code (ECC) checksum.

Checksum

checksumscheck sumcheck-sum
Associated with each page are a few bytes (typically 1/32 of the data size) that can be used for storage of an error correcting code (ECC) checksum.

Hamming code

SECDEDsingle-error correction and double-error detectionHamming matrix
Hamming codes are the most commonly used ECC for SLC NAND flash.

Reed–Solomon error correction

Reed–Solomon codeReed-SolomonReed-Solomon error correction
Reed-Solomon codes and Bose-Chaudhuri-Hocquenghem codes are commonly used ECC for MLC NAND flash.

BCH code

BCHBCH codesPeterson–Gorenstein–Zierler algorithm
Reed-Solomon codes and Bose-Chaudhuri-Hocquenghem codes are commonly used ECC for MLC NAND flash.

Semiconductor device fabrication

fabricatedsemiconductor fabricationsemiconductor manufacturing
By allowing some bad blocks, manufacturers achieve far higher yields than would be possible if all blocks had to be verified to be good.

Virtual memory

virtual storagememoryswap
When executing software from NAND memories, virtual memory strategies are often used: memory contents must first be paged or copied into memory-mapped RAM and executed there (leading to the common combination of NAND + RAM).

Memory management unit

MMUMMUsBlock Address Translation
A memory management unit (MMU) in the system is helpful, but this can also be accomplished with overlays.

Overlay (programming)

overlaysoverlayOVL
A memory management unit (MMU) in the system is helpful, but this can also be accomplished with overlays.