th58nvg1s3aft05 TOSHIBA Semiconductor CORPORATION, th58nvg1s3aft05 Datasheet - Page 30

• Manufacturer Part Number: th58nvg1s3aft05
• Description: 2gbit 256m U 8bits Cmos Nand E2 Prom
• Manufacturer: TOSHIBA Semiconductor CORPORATION

(13) Invalid blocks (bad blocks)
Bad Block Test Flow
The device occasionally contains unusable blocks. Therefore, the following issues must be recognized:
Figure 26.
ñøç ç ç
Block No.
Block No.  1
Bad Block
Bad Block
ç
No
ç ç
bad blocks, all bytes are not in the FFH state. Please don’t perform erase
operation to bad blocks.
system. Figure 27 shows the test flow for bad block detection. Bad blocks
which are detected by the test flow must be managed as unusable blocks
by the system.
isolated from the bit line by the select gate
Valid (Good) Block Number
At the time of shipment, all data bytes in a valid block are FFH. For
Check if the device has any bad blocks after installation into the
A bad block does not affect the performance of good blocks because it is
The number of valid blocks at the time of shipment is as follows:
Block No.
Block No
Read Check
Figure 27.
Start
End
ç ç
Pass
Yes
2048
1
ç
ç
2008
Fail
MIN
Bad Block *1
ç
Read Check : Read the 1st page or the 2nd page
TYP.
-
TH58NVG1S3AFT05
of each block. If the column address
0 or 2048 of the 1st page or the 2nd
page is not FF (Hex), define the
block as a bad block.
2003-05-19A
MAX
2048
Block
UNIT
30/32