SELF-CONTROLLED WRITING AND ERASING IN A MEMORISTOR CROSSBAR MEMORY
Presented By : ANKIT
INTRODUCTION Every person with a basic knowledge of electronics would be familiar with the three fundamental circuit elements — RESISTOR CAPACITOR INDUCTOR These three elements are defined by the relation between two of the four fundamental circuit variables — current, voltage, charge and flux. In 1971, Leon Chua discovered a fourth fundamental circuit element which he named as MEMRISTOR [MEMORY + RESISTOR]
BACKGROUND AND MOTIVATION In 1960, Prof. Bernard Widrow of Stanford University developed a new circuit element named- MEMISTOR. The MEMISTOR was a three-terminal device . The resistance of the MEMISTOR was controlled by CHARGE. In 1968, F. Argall published a paper, ―”Switching phenomenon in titanium oxide thin films” , whose results are similar to that of the memristor model proposed by Stanley Williams and his team.
SOMETHING MISSING Leon Chua compared the way of defining circuit elements to Aristotle‘s theory of matter. ARISTOTLE”S THEORY
In 1971, Leon Chua mathematically predicted that there is a fourthfundamental circuit element characterized by a relationship between chargeand flux linkage which he named as MEMRISTOR.
DEFINITION OF A MEMRISTOR BY LEON CHUA Memristor is defined as a two-terminal passive circuit element. The flux between the two terminals is a function of the amount of electric charge q that has passed through the device . Memristor can be used to store charge and hence this can be exploited for memory storage. Symbol of MEMRISTOR
HISTORY OF MEMORY DEVICESThe 1024-bit Selectron tube were used in 1946 Punch card reader and writer
8-level punch tape (8 holes per row)Magnetic Drum Memory of the UNIVAC computer
The row of tape drives for the UNIVAC I computerThe standard compact cassette & The Commodore Datassette
An 8-inch floppy and floppy drive next to a regular 3.5-inch floppy disk A Laserdisc next to a regular DVD
IBM Model 350, the first-ever hard disk driveA 250 MB hard disk drive from 1979
AND THE FUTURE OF MEMORY IS HERE AWAITING ! MEMRISTOR
MODEL OF MEMRISTOR FROM HP LABSIn 2008, the memristor in device form was developed by Stanley Williamsand his group in the Information and Quantum Systems (IQS) Lab at HP.Here, D is the device length and w is the length of doped region.
WRITE AND ERASE OPERATIONS A bias to memristor is applied to sample its current value. The READ circuitry will either return logic 0 or logic 1. ERASE operation is defined when memristor is taken from logic 0 to logic 1. WRITE operation is defined when memristor is taken from logic 1 to logic 0.
ADVANTAGES OF USING MEMRISTORS Provides greater resiliency and reliability . Have great data density. Faster and inexpensive than MRAM. Uses less energy and produces less heat. Would allow for a quicker boot up . Operating apart from 0’s and 1s allows it to imitate brain functions.
WHAT SETS MEMRISTORS APART !! Conventional devices use only 0 and 1; Memristor can use anything between 0 and 1 (0.3, 0.8, 0.5, etc.) Faster than Flash memory. Allow digital cameras to take pictures with no delay in between. Innovating nanotechnology due to the fact that it performs better the smaller it becomes.
FUTURE TECHNOLOGICAL SIGNIFICANCE Hope to one day have a computer that processes information in the same way as the human brain. Gaining control over the device could lead to computers that actually learn. Could lead to the replacement of the transistor. Appliances that “learn” from experiences. Could be put in cell phones as monitoring devices to track pollution and other things in the environment. Used in common devices for unbelievable storage.
CONCLUSION The showcased memristor memory extols the advantages of using the new technology in memory applications. The memristor memory exhibits lower power and energy consumption when compared to flash memory. Keeping the future aspects of Memristors in mind HP-Hynix are planning to sweep out the present day flash memories and conquer the market.