Don’t Forget the Memory…Dean Klein, VP Memory System

Development

Micron Technology, Inc.

2©2007 Micron Technology, Inc. All rights reserved.

Memory is Everywhere

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One size DOES NOT fit all…

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Question:

• How many different memories does your

computer use?

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The Evolving Memory Hierarchy

Level 1 CacheLevel 1 Cache

Level 2 CacheLevel 2 Cache

Main MemoryMain Memory

DiskDisk

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What is the Ideal Memory?

• Fast – to keep pace with processors

• Reliable – not susceptible to corruption

• Low cost – pennies per mm2

• Small – helps with low cost, but also for new

platforms

• Embeddable – ability to be integrated with

logic

• Low power – for dense systems and un-

tethered systems

• Non-volatile – no power required to retain

data

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Industry Reported Cell Sizes

Good4340.0046

Micron 60-series NAND

Excellent6780.037

Micron 40-series DRAM

1E7??5.5950.050

Samsung 512Mbit PRAM Device

Excellent28650.12

Freescale eDRAM

Unknown16900.13

Freescale TFS: Nanocrystaline

Excellent135450.27

Intel 45nm 6T-SRAM

Excellent163650.69

Freescale 6T-SRAM

Excellent441300.74

IBM/Infineon MRAM

EnduranceCell size (F2)Tech Node (nm)Cell Size (u2)

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Benefit of Shrinking

• The ability to fit more bits on a wafer,

thereby reducing the cost of those

bits.

• The ability to add features to a

product, thereby increasing

performance.

• The ability to lower the power of the

device.

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NAND Flash Memory

• The “ideal” memory?

• Non-volatile

• Small cells – Under 6F2

• Low cost process

• Scaleable?

• Wear issues?

• Slow writes

• Ideal for some applications

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NAND Read Operation

• Control Gate traps

electrons injected

by Fowler-Nordheim

tunneling.

• Voltages of up to

20V exist during

cell programming.

p-sub

N-well

p-wellN+ N+

SourceReads

0V

Drain4.5V

ControlGate

0V

0V0V0V

Cell read in “0” state

11©2007 Micron Technology, Inc. All rights reserved.

NAND Read Operation

• Control Gate traps

electrons injected

by Fowler-Nordheim

tunneling.

• Voltages of up to

20V exist during

cell programming.

p-sub

N-well

p-wellN+ N+

SourceReads >0V

Drain4.5V

ControlGate

0V

0V0V0V

Cell read in “1” state

12©2007 Micron Technology, Inc. All rights reserved.

Questions:

• In 1982, as the personal computer became

successful, how many memory bits were there

in a standard memory chip?

• In 2009, how many memory bits will be in a

leading edge standard NAND Flash memory

chip?

13©2007 Micron Technology, Inc. All rights reserved.

Questions:

1. What is the speed of light?

4. How far can light travel in the single “tick”

of a 3GHz processor clock?

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Question:

• How many ticks of the 3GHz processor clock

does it take to access the average piece of

data on a 7200RPM hard drive?

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Why SSD’s?

• Performance

• Power

• Reliability

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SSDs in Computing

1 L1 Cache 1,800

2.5 L2 Cache 1,400

1,200 DRAM 10

RelativeLatency

RelativeCost/bit

CPU

NAND Flash Closes the Latency Gap

Cost/bit Data as of November 2007

25,000,000 HDD 1NAND 25,000 SSD 3

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Notebooks: SSD’s Can Improve Battery Life

A recent editorial review highlighted that power

consumption decreases when solid state drives

are used in today’s notebook computers.

HDD SSD

PowerPower

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Notebooks: SSD’s Can Improve Battery Life

• Requirements:

A well-designed SSDEfficient Wear Management Algorithms

An Efficient Controller

Notebook Optimizations for SSD’s

Operating System ImprovementsNew SATA commands: ID and Trim

Disable Defrag

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SSD: Power and Performance

SSDs do more with less

power

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SSD’s are not just for Notebooks

• Industrial Applications

• VOD and IPTV

• Enterprise

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Memory Research Areas

• DRAM: New materials, High-K gates, Low-K dielectrics New structures: 3D transistors, lattices New features: Ultra-high bandwidth, lower power

• New types: MRAM FeRAM Polymer Programmable conductor Phase Change memory ‘Nano’ (?) Micromechanical/nano (Millipede)

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23©2007 Micron Technology, Inc. All rights reserved.

Top 10 Reasons You Want to Be an Engineer

1. For the great memories!

2. It rationalizes why you always took things apart as a kid

3. You always were fascinated by trains

4. It sure beats flippin’ burgers!

5. You love calculus, differential equations, numerical analysis…

6. At least your computer listens to you

7. You would have been a doctor or a lawyer, but where’s the challenge?

8. You believe anything is possible

9. You’re going to get rich off that cold fusion project you have going in your bathtub

10.It’s logical

Questions?