Mei-Ling Chiang, Paul C. H. Lee and Ruei-Chuan Chang
This report describes a management scheme for flash memory-based storage systems. This scheme will be implemented into a flash memory-based FAT file system in the Ramos project running in the Institute of Information Science (IIS). Ramos project targets on building software components for real time and multimedia applications that most of the consumer electronic products can be easily constructed by these software components. The flash memory-based file system is especially important to those products because flash memory is lightweight, shock-resistant, nonvolatile, power-efficient and is wildly used in these products. Flash memory has many advantages. However, the specific erase-operations before writing into flash memory are slow and power-wasted, which usually decrease system performance and consume the limited battery power. In addition to that, the number of flash memory erase cycles is also limited. In order to reduce the number of erase operations needed and to evenly wear flash memory, a new flash memory management scheme is proposed in this report. A new cleaning policy is also introduced to reduce the number of erase operations. Performance evaluations show that erase operations can be reduced by 55%.