
K9S2808V0C/B
12
SmartMedia
TM
K9S5608V0C/B
K9S6408V0C/B
SmartMedia 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 infor-
mation regarding the invalid block(s) is so called as the invalid block information. An 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 invalid block(s) via address mapping.
Identifying Invalid Block(s)
SSFDC Forum specifies the logical format and physical format to ensure compatibility of SmartMedia. Samsung pre-formats Smart-
Media in the Forum-compliant format prior to shipping. The physical format standard by SSFDC Forum specifies that invalid block
information is written at the 6th byte of spare area in invalid blocks with two or more "0" bits, while valid blocks are erased(FFh). Since
the invalid block information is also erasable in most cases, it is impossible to recover the information once it has been erased. There-
fore, 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 3). Any intentional erasure of the original invalid block information is prohib-
ited.
*
Check "FFh" at the column address 517
of the first page in the block
Figure 3. Flow chart to create invalid block table.
Start
Set Block Address = 0
Check "FFh"
Increment Block Address
Last Block
End
No
Yes
Yes
Create (or update)
Invalid Block(s) Table
No