A Retention-Error Mitigation Method on TLC NAND Flash Memory for CE Storage Systems

Abstract

Since NAND flash memory has limited P/E cycles, it could be unusable after exceeding the limited P/E cycles, and the main reason is the wear-out phenomenon in the flash memory cell. Under the influence of this phenomenon, any data can only be safely stored in the flash memory for a limited time (i.e., the retention time). As the retention time increases, the retention error rate continues to rise, and the final retention error rate could exceed the ECC (error correction code) capability. Since the retention error is the main error of NAND flash memory and its error rate is dependent on different stored states, some mitigation methods for retention errors are proposed. In the paper, we propose a retention-error mitigation method on TLC NAND flash memory for consumer electronics (CE). According to the experimental results, we can efficiently reduce the retention error rate.