k9k4g08u1m Samsung Semiconductor, Inc., k9k4g08u1m Datasheet - Page 14

• Manufacturer Part Number: k9k4g08u1m
• Description: 256m X 8 Bit / 128m X 16 Bit / 512m X 8 Bit Nand Flash Memory
• Manufacturer: Samsung Semiconductor, Inc.

K9K4G08U1M
K9F2G08U0M K9F2G16U0M
NAND Flash Technical Notes
Initial Invalid Block(s)
Initial invalid blocks are defined as blocks that contain one or more invalid bits whose reliability is not guaranteed by Samsung. The
information regarding the initial invalid block(s) is so called as the 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.
All device locations are erased(FFh for X8, FFFFh for X16) except locations where the initial invalid block(s) information is written
prior to shipping. The invalid block(s) status is defined by the 1st byte(X8 device) or 1st word(X16 device) in the spare area. Sam-
sung makes sure that either the 1st or 2nd page of every initial invalid block has non-FFh(X8) or non-FFFFh(X16) data at the column
address of 2048(X8 device) or 1024(X16 device).
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 prohibited.
Identifying Initial Invalid Block(s)
Increment Block Address
Initial Invalid Block(s) Table
Create (or update)
Figure 3. Flow chart to create initial invalid block table.
No
No
Since the initial invalid block information is also erasable in most cases, it is
Set Block Address = 0
Last Block ?
Check "FFh
or FFFFh" ?
14
Start
End
Yes
Yes
*
Check "FFh( or FFFFh)" at the column address
2048(X8 device) or 1024(X16 device)
of the 1st and 2nd page in the block
FLASH MEMORY
Preliminary