NAND flash Basics

Storage structure ：

NAND Flash from block Block make up ,block The basic unit of this is page page .

every last block By multiple page form , every last page It contains Data area( Data storage area ) And extended Spare area( Spare area ). So every one page The size is Data area+Spare area.

block ：Nandflash The smallest unit of erasure

page ：Nandflash The smallest unit of write operation

Storage unit ：

write in ： That is, control the grid to charge , Pressurize the grid , The more charge the floating gate stores , Threshold exceeded , It means 0

erase ： That is, discharge the floating grid , Below threshold , It means 1

SLC、MLC、TLC：

SLC（single-level cell）： Single media storage unit

Each storage unit stores 1bit The data of , The data stored is ：0,1

MLC（Multi-level cell)： Multistage storage unit

Each storage unit stores 2bit The data of , The data stored is ：00,01,10,11

TLC （Triple-Level Cell ）： Each storage unit stores 3bit The data of

The stored data is divided into eight types ： 000、001、010、011、100、101、110、111

Nand Flash wiring ：

DAT0~DAT7：

CE：Chip enable

WE：Write enable

RE：Read enable

CLE：Command latch enable

ALE：Address latch enable

WP：Write protect

BY / RY：Ready/Busy

Vcc：Power supply

Vss：Ground

Nand Flash Internal block diagram ：

When ALE It's high level , It's the address

When CLE It's high level , It's a command

When ALE and CLE Data is transmitted when both levels are low

BY / RY A high level indicates that programming is complete , A low level indicates busy , Programming is not finished yet

 

Operation sequence ：

Give orders , Sending address , Read and write data