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datasheet

K9F1G08U0E

FLASH MEMORY

Rev. 1.11

SAMSUNG CONFIDENTIAL

3.0 NAND FLASH TECHNICAL NOTES

3.1 Initial Invalid Block(s)

Initial invalid blocks are defined as blocks that contain one or more initial invalid bits whose reliability is not guaranteed by Samsung. The information

regarding the initial invalid block(s) is called the initial invalid block information. Devices with initial invalid block(s) have the same quality level as devices

with all valid blocks and have the same AC and DC characteristics. An initial invalid block(s) does not affect the performance of valid block(s) because it

is isolated from the bit line and the common source line by a select transistor. The system design must be able to mask out the initial invalid block(s) via

ECC.

3.2 Identifying Initial Invalid Block(s)

All device locations are erased(FFh) except locations where the initial invalid block(s) information is written prior to shipping. The initial invalid block(s)

status is defined by the 1st byte in the spare area. Samsung makes sure that either the 1st or 2nd page of every initial invalid block has non-FFh data at

the column address of 2048. Since the initial invalid block information is also erasable in most cases, it is impossible to recover the information once it has

been erased. Therefore, the system must be able to recognize the initial invalid block(s) based on the original initial invalid block information and create

the initial invalid block table via the following suggested flow chart(Figure 3). Any intentional erasure of the original initial invalid block information is pro-

hibited.

[Figure 3] Flow chart to create initial invalid block table

*

Check "FFh" at the column address 2048

Start

Set Block Address = 0

Check "FFh"

Increment Block Address

Last Block ?

End

No

Yes

Yes

Create (or update)

No

Initial

of the 1st and 2nd page in the block

Invalid Block(s) Table