GD9FS1G8F2ALG datasheet(12/55 Pages) GIGADEVICE

12 / 55 page

GD9Fx1GxF2A

5.3.2. Host Requirements

The host shall not erase or program blocks marked as defective by the manufacturer, and any attempt to do so yields

indeterminate results.

Figure of “Flow chart to create initial invalid block table” outlines the flow chart how to create an initial invalid block table. It

should be performed by the host to create the initial bad block table prior to performing any erase or programming

operations on the target. The 1st byte of both main and spare region in non

‐defective blocks are read FFh with ECC

enabled on the controller. A defective block is indicated by the majority of bits being read non

‐FFh in the Defective Block

Marking location of either the first page or last page of the block. The host shall check the Defective Block Marking location

of both the first and last past page of each block to verify the block is valid prior to any erase or program operations on that

block.

NOTE: Over the lifetime use of a NAND device, the Defective Block Marking of defective blocks may encounter read

disturbs that cause bit changes. The initial defect marks by the manufacturer may change value over the lifetime of the

device, and are expected to be read by the host and used to create a bad block table during initial use of the part.

Start

Accessing the 1st block

Check FFh at

1st byte of both main and spare data

of the first page

Check FFh at

1st byte of both main and spare data

of the last page

Last Block

End

Yes

Update a Bad Block table

Yes

Accessing next block

Figure 8: flow chart to create initial invalid block table sequential figures

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