H27U518S2CTR-BC Datasheet, PDF (32/37 Pages) Hynix Semiconductor – 512 Mb NAND Flash

1PrePreliminaryeee
H27U518S2C Series
512 Mbit (64 M x 8 bit) NAND Flash
Devices with Bad Blocks have the same quality level and the same AC and DC characteristics as devices where all the
blocks are valid. A Bad Block does not affect the performance of valid blocks because it is isolated from the bit line and
common source line by a select transistor. The devices are supplied with all the locations inside valid blocks erased(FFh).
The Bad Block Information is written prior to shipping. Any block where the 1st Byte in the spare area of the 1st or 2nd th
page (if the 1st page is Bad) does not contain FFh is a Bad Block. The Bad Block Information must be read before any
erase is attempted as the Bad Block Information may be erased. For the system to be able to recognize the Bad Blocks
based on the original information it is recommended to create a Bad Block table following the flowchart shown in Figure
22. The 1st block, which is placed on 00h block address is guaranteed to be a valid block.
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Figure 22 : Bad Block Management Flowchart
Bad Block Replacement
Rev 1.0 / Dec. 2008
32