Memristors:

Not Just MemoryShahar Kvatinsky

Technion – Israel Institute of TechnologyMay 2013

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Memristors

2L.O. Chua, “Memristor – The Missing Circuit Element,” IEEE Trans., 1971

( , )v M x i i

( , )dx

f x idt

Resistor

v R i

Capacitor

q C v

Inductor

L i

Memristor

φ

q

v

i

M q

Memristors are Real!• 2008 Hewlett Packard

3D.B. Strukov et al, “The missing memristor found,” Nature, 2008

2( ) 1 ( )v ON

OFF

RM q R q t

D

RON

ROFF

Voltage [V]

Cu

rre

nt

[mA

]

4

More Memristors

• ReRAM

• STT-MRAM

• Spintronic memristors

• Organic memristors

• Phase-change memory

5

Memristors are the Next Memory

• Dense

• Fast

• Nonvolatile

• Low power

• High endurance

Not Just Memory• Logic circuits

• Analog circuits

• Neuromorphic systems

• Sensors

• New architectures6

Why Use Memristors in Logic?

Integrating memristors with standard logic

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Logic within the memory

Memristor layer

CMOSlayer

Beyond MooreSave die area

More logic on die

Beyond Von-NeumannFlexible

Save power, BW

Memristor Polarity

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Decrease resistanceIncrease resistance

Current

Voltage

Current

Memristor Ratioed Logic (MRL)

• Voltage as logical state

• Memristors only as computational elements

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

ORAND

IN1IN1

IN2IN2

OUT OUT

AND Operation

10

Decrease resistance

AND IN2 IN1

0 0 00 1 00 0 11 1 1

ROFF

RON

0

0

No current 0

1

1

1

Increase resistance

ROFF >> RON

~0

IN1

IN2

OUT

ON ONOUT CC CC CC

ON OFF OFF

R RV V V V

R R R

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

New Architectures• Memory intensive computing

• Sea of memory

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MemoryController

Switch on Event Multithreading

Thread A

Thread B

12

Fetch

Decode 1

Decode 2

Address G

Mem access

Execute

Write back

Cache miss!!!

Low performance

High power

Simple

Continuous Flow MT (CFMT)

13

Th

read

A P

ipel

ine

reg

iste

r

R/W

R/W

R/W

R/W

R/W

Fetch

Decode 1

Decode 2

Address G

Mem access

Execute

Write back

R/W

Multistate Pipeline

Register (MPR)

S. Kvatinsky “Memristor-based Multithreading,” CAL 2013

MPR

MPR

MPR

MPR

MPR

MPR

Continuous Flow MT (CFMT)Thread A

Thread B

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Fetch

Decode 1

Decode 2

Address G

Mem access

Execute

Write back

Cache miss!!!

MP

R=

Mul

tista

te P

ipel

ine

Reg

iste

r

Neuromorphic• Memristor as a synapse

• Memristor as a neuron

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Summary

• Next memory

• Think different

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Thanks!http://memristor.shorturl.com

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