Seminar On

MAGICMEMRISTOR AIDED LOGIC

Submitted To: Submitted By:

Dept. of Electronics and Communication Lavisha Bhatia Rno. 12/129

Contents• What is Memristor• Circuit relationship• Types of Memristor• TiO2 Memristor• Working of TiO2 Memristor• Analogy of Memristor• Why Memristor• Memristor aided logic(MAGIC)• Logic gates using MAGIC

MAGIC AND MAGIC OR MAGIC NAND MAGIC NOR MAGIC NOT

• Properties of Memristor• Benefits of Memristor• Applications of Memristor• Conclusion

WHAT IS Memristor Memristor

MEMORY REGISTER A Memristor is a semiconductor whose resistance

varies as a function of flux and charge. This allows it to “remember” what has passed through the circuit.

It is characterised by “Memresistance”.

Memristance is given by: M(q)=dø/dq where ø=flux and q=charge Unit of Memristance is ohm. Therefore, Memristor can be defined as a two terminal device

which shows the relation between magnetic flux and charge.

(Symbol)

Circuit relationship

MemristorsΦ=Mq

Voltage (V)

Current(i)

Charge (q)

Flux (Φ)

Φ = Li Inductors

v=dΦ/dt i=dq/dt

Resistors v=Ri

q=CvCapacitors

DEVICE CHARACTERISTIC PROPERTY(UNITS)

DIFFERENTIAL EQUATION

RESISTOR(R) RESISTANCE(V/A, OR OHM)

R=dv/dI

Capacitor (C) Capacitance (C / V, or farad)

C = dq / dV

Inductor (L) Inductance (Wb / A, or henry)

L = dΦm / dI

Memristor (M) Memristance (Wb / C, or ohm)

M = dΦm / dq

TYPES OF Memristor

1. IONIC THIN FILM AND MOLECULAR MEMRISTORS Molecule and Ionic thin-film Memristors mostly rely on different material

properties of the thin film atomic lattices that display hysteresis below the application of charge.

These Memristors are classified into different types:• Titanium Dioxide Memristors: These types of Memristors are broadly

explored for designing and modeling.• Ionic or Polymeric Memristors: Ionic and Polymeric Memristors utilize

dynamic doping of inorganic die-electric type or polymer materials. In this type of Memristors, the charge carriers’ solid state ionic’s move all over the structure.

• Resonant Tunneling Diode Memristors: These types of Memristors use specially doped quantum well diodes of the space layers between the sources and drain regions.

• Manganite Memristors: These types of Memristors use a substrate of bilayer oxide films based on manganite as opposite to titanium dioxide Memristors.

2. MAGNETIC AND SPIN BASED MEMRISTORS Spin based Memristors are opposite to ionic nanostructure and molecule based systems, and rely on the property of degree in electronic spin.

In this type of system, the polarization of electronic spin is aware.

These types of Memristors are classified into two types:• Spintronic Memristors: In these types of Memristors, the route

of spin of electrons changes the magnetization state of the device which consequently changes its resistance.

• Spin Torque Transfer Memristors: In these types of Memristors, the comparative magnetization position of the two electrodes affect the magnetic state of a tunnel junction which in turn changes its resistance.

TiO2 Memristor

PT PTTiOv(2-x)TiO2

3 nm

2 nm

OxidizedReduced

(-)ve (+)ve

• Applied voltage makes the oxygen vacancies (+ve) to shift towards the –ve voltage.

• Titanium dioxide thin films were deposited on crystalline silicon substrates by electron beam physical vapor deposition. • The deposition was performed under vacuum ranging without process gases, resulting in homogeneous layers of TiO2-x with a thickness of around 100 nm. • Samples were then annealed at high temperatures ranging from 500 to 800 degree Celsius for 4 hours under nitrogen, and their structural and optical properties along with their chemical structure were characterized before and after annealing.• The chemical and structural characterization revealed a sub stoichiometric film with oxygen vacancies.

Working

Tio2-x

Tio2

Ron

Roff

WHY Memristor• Conventional devices use only 0 and 1 but

Memristor can use any value between 0 and 1.

• Faster than Flash memory.– Allow digital cameras to take pictures with

no delay in between.• Smaller than transistors.• Non volatile.• Generate less heat & consumes less power.

MAGIC-Memristor Aided Logic• MAGIC requires only memristors within the logic gates. • The logical state in a MAGIC gate is represented as a resistance, where the high and low resistances are considered , respectively, as logical zero and one (for simplicity, the resistance of logical zero and logical one is considered, respectively, as ROFF and RON). •The inputs and output of the logic gates are the logical states of the memristors. Separate memristors are required for the input and output. •The inputs of the MAGIC gates are the initial logical state of the input memristors, and the output is the final logical state of the memristor.• Operation of a MAGIC gate consists of two sequential stages. The first stage initializes the output memristor to a known logical state. In the second stage of operation, a voltage V0 is applied across the logic gate. While applying V0, the voltage across the output memristor depends upon the logical state of the input and output memristors.

Why Use Memristors in Logic?

Integrating memristors with standard logic

15

Logic within the memory

Memristor layer

CMOSlayer

Beyond MooreSave die area

More logic on die

Beyond Von-NeumannFlexible

Memristor Polarity

16 Decrease resistance

Current

Voltage

Current

AND Operation

17

Decrease resistance

AND IN2 IN1

0 0 00 1 00 0 11 1 1

ROFF

RON

0

0

No current 01

1

1

Increase resistance

ROFF >> RON

~0

IN1

IN2

OUT

ON ONOUT CC CC CC

ON OFF OFF

R RV V V VR R R

S. Kvatinsky “MRL – Memristor Ratioed Logic,” CNNA 2012

AND OPERATION

OR OPERATION

NAND OPERATION

NAND OPERATION WITH ‘N’ INPUTS

MAGIC NOR OPERATION

NOT OPERATION

• Remember (or recall) the last resistance it had, before being shut off.

• By changing the speed and strength of the current, it is possible to change the behavior of the device.

• A fast and hard current causes it to act as a digital device.

• A soft and slow current causes it to act as an analog device.

Properties Of Memristor

Benefits Of Memristor Technology

• Would allow for a quicker boot up since information is not lost when the device is turned off.

• Creating a Computer that never has to boot up.

• Density allows for more information to be stored.

• Has the capacity to remember the charge that flows through it at a given point of time.

• No more hard drive and RAM, just Memristor.

• Very high storage and speed.

Applications of Memristors• The most observable application of a Memristor is memory.

A Memristor can store a single bit of data in DRAM – where the capacitors are restored with Memristors.

When compared to DRAM and SRAM, this kind of memory has many benefits like – it is non-volatile

it displays good scalability it has no leakage power. This type of memory is superior to flash memory in terms of

scalability and speed.• Memristors perform equally well like the biological synapses.

This feature makes good building blocks in neuromorphic systems, where synapses and neurons are formed as electronic systems.

This kind of memory has many benefits when we compare it with the DRAM and SRAM.

• Another feasible application of Memristors is logic circuits. These can be used as a standalone logic

gate, or used in hybrid CMOS Memristor circuits.

One notable logic application of Memristors is its usage in an FPGA as configurable switch

and in connecting the CMOS logic gates.• Thus, in future Memristors can be used to do

digital logic using implication instead of NAND.

Conclusion

It is sure that Memristor is going to revolute the 21st century as radically as the transistor in the 20th century But Memristor will have to wait a few years for a killer app like transistor which had to wait almost a decade after it’s invention for the killer app in the form of hearing aids

Finally as Leon O Chua mentioned “It’s time to rewrite al the Electronics textbooks”

References How We Found the Missing Memristor by Stanley Williams, IEEE

Spectrum December 2008. L.O, Chua, Memristor-missing circuit clement, IEEE Tans . Circuit Theory, Vol. 18, 1971, pp. 507-519. Memristor and Memristive Systems Symposium, University of California,

Berkeley, November 21,2008. Stateful Implication Logic with Memristors by Eero Lehtonen, Mika Laiho

2009 IEEE/ACM International Symposium on Nanoscale Architectures

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