International Journal of Research and Scientific Innovation (IJRSI) | Volume VI, Issue V, May 2019 | ISSN 2321–2705

Third Generation Solid State Drives

Thrapthi Shetty

Assistant Professor, Department of Electronics and Communication, A.J Institute of Engineering and Technology, Kottara Chowki, Mangalore, Karnataka, India

Abstract: solid state is a term that refers to electronic circuitry that is built entirely out of semiconductors. the term was originally used to define those electronics such as a transistor radio that used semiconductors rather than vaccum tubes in construction. A Solid state drive (SSD) is a non volatile memory system that emulates a magnetic hard disk drive (HDD).SSD depends on flash memory chips to store data ,it does not contain moving parts. With proper design, SSD provides high data transfer rates, low access time, improved tolerance to shock and vibration and reduced power consumption. The improved performance and durability outweigh the higher cost of an SSD relative to an HDD for some applications. SSD uses NANdD based flash memory or DRAM to store data. SSD uses solid state memory to store persistent data. HDDs store their data on spinning metal plateers, and whenever computer wants to access data, a little needle –like component called the “head” moves to the data’s position and provides it to the computer writing data to a HDD works in a similar fashion, where parts are constantly moving, SSDs don’t move. SSD process seems a bit more direct and efficient, speed is the primary advantage of an SSD over a traditional HDD.

I. INTRODUCTION

1.1. Types of flash memory

There ate two types of flash memory,NAND and NOR.NAND and NOR refers to the type of logic gate used in each memory cell.Both contain cells and transsitors in a grid but the wiring betweeb the cells differs.The cells are wired in parallel in NOR flash and the cells are wired innseries in NAND flash. NAND cell require fewer wires and can be packed on a chip in greater density.NOR cell requires more wires ,They are more complex.As a result NAND lash is less expensive and it can read and write data much more rapidly.

1.2 Architecture of SSD

Memory

Flash memory is an electronic (solid-state) non volatile computer storage medium that can be electrically erased and reprogrammed.
Information is stored in an array of memory cells made from floating-gate transistors in flash memory. Each cell stores only one bit of information in single –level cell (SLC) devices. Multi-level cell (MLC) devices, including triple-level cell (TLC) devices, can store more than one bit per cell.