K9K1208Q0C
K9K1208D0C
K9K1208U0C
K9K1216Q0C
K9K1216D0C
K9K1216U0C
FLASH MEMORY
NAND Flash Technical Notes
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 so called as 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 address mapping. The 1st block, which is
placed on 00h block address, is guaranteed to be a valid block, does not require Error Correction up to 1K program/erase cycles.
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 6th byte(X8 device) or 1st word(X16 device) in the spare area. Samsung makes sure
that either the 1st or 2nd page of every initial invalid block has non-FFh(X8 device) or non-FFFFh(X16 device) data at the column
address of 517(X8 device) or 256 and 261(X16 device). 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 initial invalid block information and create the initial invalid block table via the following suggested flow
chart(Figure 3). Any intentional erasure of the initial invalid block information is prohibited.
Start
Set Block Address = 0
Increment Block Address
Check "FFh" at the column address
517(X8 device) or 256 and 261(X16 device)
of the 1st and 2nd page in the block
*
No
No
Create (or update)
Initial
Invalid Block(s) Table
Check "FFh" ?
Yes
Last Block ?
Yes
End
Figure 3. Flow chart to create initial invalid block table.
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SAMSUNG [ SAMSUNG ]
