A simple wear leveling algorithm for NOR type solid storage device

Abstract

The role and importance of solid storage devices (SSD) is rapidly increasing for the purpose of data storage. The SSDs are rapidly replacing the old fashioned and traditional magnetic storage medium. Few factors responsible for this metamorphic turnaround are due to the better performance and low power requirement of SSDs. But, as with every pros there are some associated cons. One limiting factor of SSDs in replacing traditional magnetic storage media is its low endurance. These solid state devices can be re-programmed for a limited number of times. Unlike, magnetic storage media, the SSDs can be re-programmed for a limited number of times. Internally, SSDs are organized either in bytes or blocks. Generally, for memory access operations, either the byte or blocks are used. With each write operation, the byte gets worn out and its lifetime decreases. To guard this limiting factor of SSD, wear leveling mechanism is used. Wear leveling mechanism is provided as a feature in flash type SSDs, which evenly distributes the write operation throughout the flash memory and prevents the early wear out of memory. The existing wear leveling mechanism is limited only to flash type SSDs. In this paper, we propose a wear leveling algorithm for SSD and precisely NOR type SSD. NAND types SSDs are well equipped with algorithms to enhance their life and reliability. The algorithm proposed will provide a mechanism that will enhance the life, endurance and reliability of SSD of NOR type.