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Transcript of UMD_2008 for Stan.ppt
4©2007 Micron Technology, Inc. All rights reserved.
Question:
• How many different memories does your
computer use?
5©2007 Micron Technology, Inc. All rights reserved.
The Evolving Memory Hierarchy
Level 1 CacheLevel 1 Cache
Level 2 CacheLevel 2 Cache
Main MemoryMain Memory
DiskDisk
6©2007 Micron Technology, Inc. All rights reserved.
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
7©2007 Micron Technology, Inc. All rights reserved.
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)
8©2007 Micron Technology, Inc. All rights reserved.
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.
9©2007 Micron Technology, Inc. All rights reserved.
NAND Flash Memory
• The “ideal” memory?
• Non-volatile
• Small cells – Under 6F2
• Low cost process
• Scaleable?
• Wear issues?
• Slow writes
• Ideal for some applications
10©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 “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?
14©2007 Micron Technology, Inc. All rights reserved.
Question:
• How many ticks of the 3GHz processor clock
does it take to access the average piece of
data on a 7200RPM hard drive?
16©2007 Micron Technology, Inc. All rights reserved.
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
17©2007 Micron Technology, Inc. All rights reserved.
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
18©2007 Micron Technology, Inc. All rights reserved.
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
19©2007 Micron Technology, Inc. All rights reserved.
SSD: Power and Performance
SSDs do more with less
power
20©2007 Micron Technology, Inc. All rights reserved.
SSD’s are not just for Notebooks
• Industrial Applications
• VOD and IPTV
• Enterprise
21©2007 Micron Technology, Inc. All rights reserved.
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)
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