k9f1208u0a-y Samsung Semiconductor, Inc., k9f1208u0a-y Datasheet - Page 17

• Manufacturer Part Number: k9f1208u0a-y
• Description: 64m X 8 Bit , 32m X 16 Bit Nand Flash Memory
• Manufacturer: Samsung Semiconductor, Inc.

K9F1208D0A
K9F1208U0A
NAND Flash Technical Notes
Error in write or read operation
Within its life time, the additional invalid blocks may develop with NAND Flash memory. Refer to the qualification report for the actual
data.The following possible failure modes should be considered to implement a highly reliable system. In the case of status read fail-
ure after erase or program, block replacement should be done. Because program status fail during a page program does not affect
the data of the other pages in the same block, block replacement can be executed with a page-sized buffer by finding an erased
empty block and reprogramming the current target data and copying the rest of the replaced block. To improve the efficiency of mem-
ory space, it is recommended that the read or verification failure due to single bit error be reclaimed by ECC without any block
replacement. The said additional block failure rate does not include those reclaimed blocks.
ECC
Program Flow Chart
Write
Read
Program Error
*
No
K9F1216D0A
K9F1216U0A
Single Bit Failure
Failure Mode
Erase Failure
Program Failure
: Error Correcting Code --> Hamming Code etc.
Read Status Register
Example) 1bit correction & 2bit detection
Write Address
or R/B = 1 ?
I/O 0 = 0 ?
Write Data
I/O 6 = 1 ?
Write 10h
Write 80h
Start
Yes
Yes
(Continued)
No
17
*
Status Read after Program --> Block Replacement
Read back ( Verify after Program) --> Block Replacement
Status Read after Erase --> Block Replacement
Verify ECC -> ECC Correction
: If program operation results in an error, map out
the block including the page in error and copy the
target data to another block.
Detection and Countermeasure sequence
Program Completed
Wait for tR Time
Write Address
If ECC is used, this verification
operation is not needed.
Verify Data
Write 00h
Yes
FLASH MEMORY
or ECC Correction
No
Program Error
*