ESMT

F59L512M81A

Elite Semiconductor Memory Technology Inc.

Publication Date: May

2014

Revision: 1.0

11/40

Error in write or read operation

Within its lifetime, 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 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 or verification failure due to single bit error be reclaimed by

ECC without any block replacement. The additional block failure rate does not include those reclaimed blocks.

Failure Mode

Detection and Countermeasure sequence

Erase failure

Read Status after Erase → Block Replacement

Write

Program failure

Read Status after Program → Block Replacement

Read

Up to 4 bits failure

Verify ECC → ECC Correction

Note

: Error Correcting Code --> RS Code or BCH Code etc.

Example: 4bit correction / 512 Byte

Program Flow Chart