NAND Flash分类
SLC (Single-Level Cell) architecture: a single memory cell (Cell) store 1bit data,
MLC (Multi-Level Cell) architecture: a single storage unit (Cell) 2bit data store.
SLC
「Small page (528 Byte)、Large page (2112 Byte)」
Stored in each storage unit (Cell) within an information bit (bit), called single-stage storage unit (single-level cell, SLC), use this storage unit is also known as flash memory to store a single stage flash memory cell (SLC flash memory), or simply SLC flash memory. Advantages of SLC flash memory is faster transmission speed, lower power consumption and longer life storage unit. However, since the information contained in each storage unit is less, which per million bytes takes higher cost to produce.

 
 

 

MLC
「Large page (2112 Byte)、Large page (4224 Byte)」
Multi-stage flash memory storage unit (Multi-level cell flash memory, MLC flash memory) can store two or more bits of information in each storage unit, its "multi-stage" refers to more than one set charging voltage charge value, and so will be able to store more than one bit of value to each storage unit. Because each storage unit can store more bits, so the cost per unit of storage MLC flash memory is relatively cheap. Earlier than SLC flash memory, MLC transmission speed is slower, higher power consumption and lower life storage unit for the shortcomings, but advances in technology, continuous improvement of yield problems, NAND Flash market today are for the majority of MLC architecture.

 
 
 


 
 
 
NAND Flash 资料结构

 

 
 

NAND Flash Invalid Block 
NAND Flash at the factory will make rigorous testing program to confirm each Block (Block, rail area) is normal, Block does not pass the test will be marked with a sign, which is called Block Initial Invalid Block (Potential Bad Block ). The Initial Invalid Block information is very important and can not be easily removed, because after some Block Erase Invalid block information will be gone, then use the programmer or user's own burner manufacturers are unable to identify these Invalid block . Invalid Block marked position in the SLC, MLC will not need the same attention (there will be differences between different brands).