A Data Recovery Technique Improves on Hybrid Mapping for NAND Flash Memory

Abstract

Flash memory has been built upon EEPROM (Electronically Erasable Programmable Read-Only Memory). Unlike traditional magnetic disks, Flash memory has disadvantages, like the limitations of life cycle and erase-before-write, which require a resolution well-known namely Flash Translation Layer (FTL) to resolve. Volatile memory today is used to save periodic retrieve requests for mapping-tables in flash memory. These tables can be missed when an unexpected power outage occurs. In order to address this problem, Page-mapping, Block- mapping, and Hybrid-mapping methods have been introduced. However, these methods also have shortcomings, for example, the mapping-information management overhead and the recovery time. In this paper, we introduce a data recovery scheme improves on Hybrid-mapping together with the spare area separate to ECC (Error Code Correction), block information, ASN (Allocation Sequence Number), mapping-information, Flag, and reserved in FTL. The results display that our technique has the less recovery time and mapping-information management overhead than the previous methods.