k9k4g08u1m Samsung Semiconductor, Inc., k9k4g08u1m Datasheet - Page 15

• Manufacturer Part Number: k9k4g08u1m
• Description: 256m X 8 Bit / 128m X 16 Bit / 512m X 8 Bit Nand Flash Memory
• Manufacturer: Samsung Semiconductor, Inc.

K9K4G08U1M
K9F2G08U0M K9F2G16U0M
NAND Flash Technical Notes
Error in write or read operation
Within its life time, additional invalid blocks may develop with NAND Flash memory. Refer to the qualification report for the block
failure rate.The following possible failure modes should be considered to implement a highly reliable system. In the case of status
read failure 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. In case of Read, ECC
must be employed. To improve the efficiency of memory space, it is recommended that the read failure due to single bit error should
be reclaimed by ECC without any block replacement. The block failure rate in the qualification report does not include those
reclaimed blocks.
ECC
Program Flow Chart
Write
Read
Single Bit Failure
Failure Mode
: Error Correcting Code --> Hamming Code etc.
Erase Failure
Program Failure
Example) 1bit correction & 2bit detection
Program Error
*
(Continued)
No
Read Status Register
Program Completed
Write Address
or R/B = 1 ?
I/O 0 = 0 ?
Write Data
I/O 6 = 1 ?
Write 10h
Write 80h
Start
15
Yes
*
Yes
Status Read 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
No
FLASH MEMORY
Preliminary