A Survey of Address Translation Technologies for Flash Memories

摘要

Flash is a type of Electronically Erasable Programmable Read-Only Memory (EEPROM). Different from traditional magnetic disks, flash memories have no moving parts and are purely electronic devices, giving them unique advantages, such as lower access latency, lower power consumption, higher density, shock resistance, and lack of noise. However, existing applications cannot run directly on flash memories due to their special characteristics. Flash Translation Layer (FTL) is a software layer built on raw flash memories that emulates a normal block device like magnetic disks. Primary functionalities of the FTL include address translation, garbage collection, and wear leveling. This survey focuses on address translation technologies and provides a broad overview of existing schemes described in patents, journals, and conference proceedings.