Flash Related Knowledge Summary

1.nor Flash and Nandflash difference

(1) Nor flash can directly access, no special interface circuit, storage capacity is small; Nandflash has a special address decoding interface circuit, can achieve high storage density, large storage capacity;

(2) nor flash can store program code, the program can run directly, Nandflash can not run directly;

(3) Norflash erase the block are relatively large, the time spent longer than nandflash;

(4) Nanflash life can be up to million, norflash life of 100,000 times, Nandflash prone to bad block problems, should have special bad block management;

2.CFI, JEDEC, MTD and flash main algorithms and manufacturers

CFI is the public flash interface [Common Flashinterface], which is used to help the program get operational information from the Flash chip without having to hard-code the Flash ID in the program.

JEDEC is an international agreement made by manufacturers, mainly for computer memory development. JEDEC is used to help the program read the Flash's manufacturer ID and device ID to determine the size and algorithm of the flash if the chip does not support

CFI, you need to use the JEDEC. However, flash that supports the CFI interface does not necessarily support the JEDEC standard.

MTD (Memory Technology device Memory technology device) is a subsystem of Linux for accessing memory devices (ROM, Flash). The main purpose of MTD is to make the new memory device more simple to drive,

For this it provides an abstract interface between the hardware and the upper layer. All of MTD's source code is in the/DRIVERS/MTD subdirectory.

The main algorithms are:

Intel algorithm

Intel:in28fxxx in48fxxx

Sharp:lh28f016xxx

AMD algorithm

Amd:am29lvxxx am29dlxxx

Fujitsu:mbm29lvxxx mbm29dlxxx mbm29plxxx MBM29XLXX

St:m29dwxxx m29wxxx

Toshiba:tc58fvbxxx (or TOSHIBA algorithm)

Spansion:s29glxxx

Macronix:mx29lvxxx

Atmel algorithm

Atmel:at49bvxxx at49fxxx

Sst:sst39lfxxx sst39vfxxx

Samsung algorithm

Samsung:k9nbgxxx

Hynix algorithm

Hy27ugxxx