K9F2808Q0C-HCB0 SAMSUNG [Samsung semiconductor], K9F2808Q0C-HCB0 Datasheet - Page 12

• Manufacturer Part Number: K9F2808Q0C-HCB0
• Description: 16M x 8 Bit NAND Flash Memory
• Manufacturer: SAMSUNG [Samsung semiconductor]

K9F2808U0C
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.
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 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 517. 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 sug-
gested flow chart(Figure 3). Any intentional erasure of the initial invalid block information is prohibited.
Increment Block Address
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 fully guaranteed to be a valid block, does not require Error Correction
cycles.
Invalid Block(s) Table
Create (or update)
Initial
Figure 3. Flow chart to create initial invalid block table.
No
No
Set Block Address = 0
Check "FFh" ?
Last Block ?
12
Start
End
Yes
Yes
*
Check "FFh" at the column address
517
of the 1st and 2nd page in the block
FLASH MEMORY
up to 1K program/erase