Flash memory is a constantly-powered nonvolatile semi-conductor device that has the advantages of small size, fast access, low power consumption, convenient portability, shock resistance, data retention after a power off, random access, and heat dissipation. Flash memory is currently being integrated with different embedded system devices such as in digital cameras, smart phones, PDAs, and sensor devices. However, as flash memory has special characteristics like wear-leveling and “erase-before-write”, a FTL (flash translation layer) at software layer should be included. Though even the power off recovery is very important in portable devices most FTL algorithms did not consider the power off recovery scheme.
In this paper we proposed a Recovery Technique for flash memory Using Shadow Paging (RTUSP) for flash memory based storage devices. To overcome the sudden power off, our idea saves the map block information in two tables: the first one is original and the second one is a copy one. Our technique improves the capacity of flash memory and is compatible the existing FTL algorithms.
