k9f4g08u0m-y Samsung Semiconductor, Inc., k9f4g08u0m-y Datasheet - Page 14

• Manufacturer Part Number: k9f4g08u0m-y
• Description: 512m X 8 Bits / 1g X 8 Bits Nand Flash Memory
• Manufacturer: Samsung Semiconductor, Inc.

K9K8G08U1M
K9F4G08U0M
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 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. In case of Read, ECC must be
employed. To improve the efficiency of memory 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
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
14
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
Advance