K522H1HACF-B050 Datasheet, PDF (18/94 Pages) Samsung semiconductor – MCP Specification

K522H1HACF-B050
datasheet
Rev. 1.0
MCP Memory
2.0 NAND Flash Technical Notes
2.1 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
address mapping. The 1st block, which is placed on 00h block address, is guaranteed to be a valid block up to 1K program/erase cycles with x8:1bit/
512Byte, x16:1bit/256Word ECC.
2.2 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(1st word) 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(x16:1024). 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 5). Any intentional erasure of the original initial invalid
block information is prohibited.
Start
Set Block Address = 0
Increment Block Address
Create (or update)
Initial
Invalid Block(s) Table
* Check "FFh(x16:FFFFh)" at the
column address 2048(x16:1024)
of the 1st and 2nd page in the block
No
Check
"FFh(x16:FFFFh)"
Yes
No
Last Block ?
Yes
End
Figure 5. Flow chart to create initial invalid block table
- 18 -