Elettronica T A.A. 2015-2016 Introduction

Digital integrated circuits rEvolution

Elettronica T A.A. 2015-2016 Introduction

Introduction

Digital Integrated Circuit Design: The past, the present and the future

» What made Digital IC design what it is today» Why is designing digital Ics different today than

it was before?» Will it change in the future?

Elettronica T A.A. 2015-2016 Introduction

The First Computer

The BabbageDifference Engine(1832)

25,000 partscost: £17,470

Elettronica T A.A. 2015-2016 Introduction

ENIAC - The first electronic computer (1946)

Balistic calculator (Used during 2° World War)

18000 valves1500 relais30 tons200 KW

$ 486.804,22 (1946)

During 10 years of opeating life 19000 valves had to be replaced

Elettronica T A.A. 2015-2016 Introduction

The transistor revolution

First transistor

Shockley, Brattain,Bardeen

Bell Labs, 1948

Same Functionality of vacuum tubes but less power and compact, reliable and fast.

Elettronica T A.A. 2015-2016 Introduction

The first Integrted Circuit

Improvement on technology process :

» Planar Transistors (BJT)

Phase shift oscillator – Jack Kilby (1958)

Integration of many transistors on the same semiconductor substrate

Elettronica T A.A. 2015-2016 Introduction

The first integrated circuit

ECL 3-input GateTechnology: bipolarMotorola 1966

Noyce –Fairchil Co-Founder

Idea: Planar transistor Process in a single shot

several transistor Manufactoring steps

Doping Oxidation Lithografy Etching Deposition EtcBeginning of the IC REVOLUTION!!!

Elettronica T A.A. 2015-2016 Introduction

Transistor – Transistor Logic

TTL is a class of digital circuits built from bipolar junction transistors (BJT) and resistors.

Became very popular after 1963 (Texas) 7400 and 5400 series

Main issue:» Speed» Power

Elettronica T A.A. 2015-2016 Introduction

MOS transistor

Patented : 1935 (IGFET)...Reinvented in late ‘60.First working device : ‘70

Elettronica T A.A. 2015-2016 Introduction

Microprocessors

Intel 4004 (1971)2300 transistors3x4mm10um process PMOS<1 MHz operation

Elettronica T A.A. 2015-2016 Introduction

Microprocessors

Intel 4004 (1971)2300 transistors3x4mm10um process PMOS<1 MHz operation

Elettronica T A.A. 2015-2016 Introduction

Intel Core 2 Microprocessor

Intel Core 2 (2006), 291M transistors,65CMOS, 143mm²3GHz

Elettronica T A.A. 2015-2016 Introduction

Transistor Counts

Elettronica T A.A. 2015-2016 Introduction

Intel SRAM Prototype Chip (2009)

22nm 364MB SRAM > 2.9B transistor 3rd generation High-K + Metal Gate

Elettronica T A.A. 2015-2016 Introduction

Moore’s Law In 1965, Gordon Moore noted that the number of transistors on a chip doubled

every 18 to 24 months He made a prediction that semiconductor technology will double its

effectiveness every 18 months

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Elettronica T A.A. 2015-2016 Introduction

Cost per Transistor

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0.00001

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1982 1985 1988 1991 1994 1997 2000 2003 2006 2009 2012

cost: ¢-per-transistor

Fabrication capital cost per transistor (Moore’s law)

Elettronica T A.A. 2015-2016 Introduction

Scaling

Transistor count is the most common measure of integrated circuit complexity.

» Intel's 10-core XeonWestmere-EX 2.5 Billion» Xilinx currently holds the "world-record" for

an FPGA containing 6.8 Billion transistors.

More integration due transistor scaling:» More compact devices» faster» Less power hungry

Elettronica T A.A. 2015-2016 Introduction

65nm CMOS Technology

8 Metal Layers for local/global interconnects

PMOS (gate 65nm)

Elettronica T A.A. 2015-2016 Introduction

Evolution in Complexity

memories

Elettronica T A.A. 2015-2016 Introduction

Frequency

P6

Pentium ® proc486

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0.1

1

10

100

1000

10000

1970 1980 1990 2000 2010Year

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qu

ency

(M

hz)

Lead Microprocessors frequency doubles every 2 yearsLead Microprocessors frequency doubles every 2 years

Doubles every2 years

Courtesy, Intel

Now it’s over!

Elettronica T A.A. 2015-2016 Introduction

Power Dissipation Prediction (2000)

Elettronica T A.A. 2015-2016 Introduction

Power density

40048008

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Hot Plate

Nuclear

Reactor

Rocket

Nozzle

Power density too high to keep junctions at low tempPower density too high to keep junctions at low temp

Courtesy, Intel

Elettronica T A.A. 2015-2016 Introduction

Not enough cooling

Elettronica T A.A. 2015-2016 Introduction

Why Scaling?

Technology shrinks by 0.7/generation With every generation can integrate 2x more functions per chip; chip cost

does not increase significantly Cost of a function decreases by 2x But …

» How to design chips with more and more functions?» Design engineering population does not double every two years…

Hence, a need for more efficient design methods» Exploit different levels of abstraction

Elettronica T A.A. 2015-2016 Introduction

Design Abstraction Levels

n+n+S

GD

+

DEVICE

CIRCUIT

GATE

MODULE

SYSTEM

Elettronica T A.A. 2015-2016 Introduction

26

Not Only Microprocessors (cell phone…)

Analog Baseband

Digital Baseband

(DSP + MCU)

PowerManagemen

t

Small Signal RF

PowerRF

Elettronica T A.A. 2015-2016 Introduction

Challenges in Digital Design

“Microscopic Problems”• Ultra-high speed design Interconnect• Noise, Crosstalk• Reliability, Manufacturability• Power Dissipation• Clock distribution.

Everything Looks a Little Different

“Macroscopic Issues”• Time-to-Market• Millions of Gates• High-Level Abstractions• Reuse & IP: Portability• Predictability• Verification

…and There’s a Lot of Them!

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