K9K1G08U0M-YIB0 Samsung semiconductor, K9K1G08U0M-YIB0 Datasheet - Page 10

• Manufacturer Part Number: K9K1G08U0M-YIB0
• Description: 128M x 8 Bit NAND Flash Memory
• Manufacturer: Samsung semiconductor

NAND Flash Technical Notes
Invalid Block(s)
Invalid blocks are defined as blocks that contain one or more invalid bits whose reliability is not guaranteed by Samsung. The i nfor-
mation regarding the invalid block(s) is so called as the invalid block information. Devices with invalid block(s) have the same quality
level or as devices with all valid blocks and have the same AC and DC characteristics. An invalid block(s) does not affect the perfor-
mance 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 invalid block(s) via address mapping. The 1st block of the NAND Flash, however, is fully guaranteed to
be a valid block. The 1st block, which is placed on 00h block address, is fully guaranteed to be a valid block, does not require Error
Correction.
All device locations are erased(FFh) except locations where the invalid block(s) information is written prior to shipping. The i nvalid
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 invali d
block has non-FFh data at the column address of 517. Since the invalid block information is also erasable in most cases, it is impos-
sible to recover the information once it has been erased. Therefore, the system must be able to recognize the invalid block(s) based
on the original invalid block information and create the invalid block table via the following suggested flow chart(Figure 4). Any inten-
tional erasure of the original invalid block information is prohibited.
K9K1G08U0M-YCB0, K9K1G08U0M-YIB0
Identifying Invalid Block(s)
Increment Block Address
Invalid Block(s) Table
Create (or update)
Figure 4. Flow chart to create invalid block table.
No
No
Set Block Address = 0
Check "FFh" ?
Last Block ?
10
Start
End
Yes
Yes
*
Check "FFh" at the column address 517
of the 1st and 2nd page in the block
FLASH MEMORY