8.NandFlash principle Analysis

8.NandFlash principle Analysis

This section is mainly about Nandflash knowledge, first of all, the role, classification and access of Nandflash.

1. Role analysis: In the personal PC, use the hard disk to store the operating system, data and other information. In the field of embedded, it is called Nandflash with HDD function. So Nandflash is the storage of information.
2. Nandflash classification:

Outline of SLC principle:

Outline of MLC Principle:

From above you can see that the MLC storage density is twice times larger than the SLC storage density, and they compare the information between them:

Next is the access method:

1. Address method.
2. The address structure.
3. Signal pins.

1. Addressing method:

First look at the memory address mode diagram (ARM9):

The above is the schematic of the memory, there are address lines and data lines, both are connected to the CPU.

You can see that there are no data lines and address lines like memory in the Nandflash schematic diagram. The memory used here is the unified address, that is, the memory is included in the space. The Nandflash is in the address space, independent addressing. Working diagram of Nandflash:

2. Address structure:

K9f2g08u0a-nand Basic components of Flash:

It can be seen that a nandflash device is divided into blocks, each of which is divided into multiple pages, each of which is divided into (2k+64) Bytes. Where 2K is the main data area of the data, and 64Bytes is the free data area of information such as check code.

The line address is the page number, to access the storage unit, you need to know the page number (column address), the column address is the offset in the page, you can locate the unit to be accessed.

3. Pin signal:

Signal information for the rest of the pin.

8.NandFlash principle Analysis