nanotechnology: spatial computing using molecular electronics mihai budiu joint work with seth copen...

Nanotechnology: Spatial Computing Using Molecular

Electronics

Mihai Budiujoint work with

Seth Copen Goldstein

Dan Rosewater

SSS April 20, 2001 2

Intersection of Three Areas

Reconfigurablecomputing

Nanotechnology

Computerarchitecture


Prophecies, A Risky Endeavor

I think there is a world market for maybe five computers.

--- T. J. Watson

640K ought to be enough for everybody. --- Bill Gates

There is no reason anyone would want a computer in their home. --- Ken Olson

I will propose this semester.--- Anonymous

There is not the slightest indication that nuclear energy will ever be obtainable.

--- Albert Einstein


Moore’s Law


Moore’s Second Law

Plant cost Mask cost

generation

X 1

000$


Our Proposal

Nanotechnology+ cheap+ high-density+ low-power– unreliable

Computer architecture+ vast body of knowledge – expensive– high-power

Reconfigurable Computing+ defect tolerant+ high performance– low density

++++ +

+_

__

_


Paradigm Shift

Executable Configuration

Complex fixed chip+

Program

Dense, regular structure+

Configuration


Outline

Introduction

• Reconfigurable computing

• Nanotechnology

• Nano-architecture proposal

• Preliminary results

• Conclusions and Future Work


Reconfigurable Computing

• Back to ENIAC-style computing

• Synthesize one machine to solve one problem

SSS April 20, 2001 10

Island-Style RC Architecture

Universal gates

and/or

storage elements

Interconnectionnetwork

Programmable Switches

SSS April 20, 2001 11

Switch controlled by a 1-bit RAM cell

0001

Universal gate = RAM

a0a1a0

a1

dataa1 & a2

0data in

control

Main RC Ingredient: RAM Cell

SSS April 20, 2001 12

Place and Route

int reverse(int x){ int k,r=0; for (k=0; k<64; k++) r |= x&1; x = x >> 1; r = r << 1; }}int func(int* a,int *b){ int j,sum=0; for (j=0; *a>0; j++) sum+=reverse(*b

SSS April 20, 2001 13

Kernel Speedup Using PipeRench

189.7

15.511.3 12.0

63.342.4

26.0

57.1

29.0

1

10

100

1000

ATR

Cordic

DCT

DCT-2D

FIRID

EA

Nquee

nsOve

r

PopCou

ntTim

es O

ver

300M

hz

Ult

raS

par

c-II

SSS April 20, 2001 14

Defect Tolerance

Despite having >70% of the chips defective, Teramac works flawlessly.

Compilation has two phases:• defect detection through self-testing• placement for defect-avoidance

SSS April 20, 2001 15

Outline

Introduction Reconfigurable computing

• Nanotechnology



• Conclusions and Future work

SSS April 20, 2001 16

Nanotechnology

SSS April 20, 2001 17

Predicted Features

• Low Power: 1010 gates use less than 2 W(compare to 3x107 transistors using 100 W in

CMOS)

• Low cost (nanocents/gate)

• Small size (105 factor area gain)

Nano-RAM cell

In yellow: a CMOS RAM cell.

SSS April 20, 2001 18

Nano-wires

• carbon nanotubues, Si, metal• >2nm diameter, up to mm length• excellent electrical properties

A carbon nanotube: one molecule

SSS April 20, 2001 19

Nano-switch

SSS April 20, 2001 20

Nano-switch Between Nano-wires

SSS April 20, 2001 21

Self-assembly

SSS April 20, 2001 22

No Complex Irregular Structures

SSS April 20, 2001 23

No Three-Terminal Devices

SSS April 20, 2001 24

Diode-resistor Logic

VDD

OutputInput 1

Input 2

A * B

V AND

BA

A ^ B

VVV AND

A

BA

B

A * B

Nano-implementation Electrical equivalent

SSS April 20, 2001 25

Nanoscale Latches

D clock

data out

Provide:• signal restoration (amplification)• clocking (synchronization)• memory

SSS April 20, 2001 26

High Defect Rate

SSS April 20, 2001 27

Outline

Introduction Reconfigurable computing Nanotechnology



• Conclusions and future work

SSS April 20, 2001 28

The nanoBlock (3-in to 3-out Logic)

+VddG

nd

Gndclk

Inputs

Outputs

CMOS

clk

SSS April 20, 2001 29

Interconnecting nanoBlocks

Switch block

SSS April 20, 2001 30

Global View

SSS April 20, 2001 31

Con

trol

cluster

long-lines

Many Clusters = nanoFabric

SSS April 20, 2001 32

Compilation

1. Program

2. Split-phase Abstract Machines

3. Configurations placed independently

4. Placement on chip

int reverse(int x){ int k,r=0; for (k=0; k<64; k++) r |= x&1; x = x >> 1; r = r << 1; }}

Computations& local storage

Unknown latency ops.

SSS April 20, 2001 33

Outline

Introduction Reconfigurable Hardware Nanotechnology Nano-architecture proposal


• Conclusions and Future work

SSS April 20, 2001 34

A graph of the whole program execution:

A Limit Study of Performance

Memory word

Basic block

Memory write

Memory read

Control-flow transfer

SSS April 20, 2001 35

Area(106 units/cm2 available)

0

50000

100000

150000

200000

250000

099.

go

129.

com

pres

s13

0.li

132.

ijpeg

adpc

m_d

adpc

m_e

epic_

e

g721

_Q_d

g721

_Q_e

gsm

_d

gsm

_e

jpeg_

d

jpeg_

e

mpe

g2_d

un

its

memory area

code area

SSS April 20, 2001 36

Typical Program Graph (g721_e)

Control flow transfer

100% memory cluster

Memory reads

100% code cluster

SSS April 20, 2001 37

Typical Program Graph (g721_e)

Control flow transfer

memory

Memory reads

code

memcpy

SSS April 20, 2001 38

Program Graph After Inlining memcpy

memcpy

SSS April 20, 2001 39

Application Slowdown

-1

0

1

2

3

4

5

6

7

8

9

10

11

tim

es s

low

er t

han

nat

ive

1 clock/square 5 clocks/square

SSS April 20, 2001 40

How Time Is Spent

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

099.g

o

129.c

ompr

ess

130.l

i

132.i

jpeg

adpc

m_d

adpc

m_e

epic_

e

g721

_Q_d

g721

_Q_e

gsm

_d

gsm

_e

jpeg_d

jpeg_e

mpe

g2_d

per

cen

t

idle

executioncontrol flow

register traffic

No caches: reads expensive

No speculation

SSS April 20, 2001 41

Future Work

• Better nano-devices

• More accurate hardware models in simulations

• Compilation technology

SSS April 20, 2001 42

Conclusions

• Electronic nanotechnology promises to transcend the limitations of CMOS

• Nanofabrics are very well suited to reconfigurable computation

• 109-gate designs can be managed through hierarchies of abstract machines

nanotechnology: spatial computing using molecular electronics mihai budiu joint work with seth copen...

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