Low Power Systems Using Transmeta Crusoe Processors Bill Gervasi Technology Analyst, Transmeta...
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Transcript of Low Power Systems Using Transmeta Crusoe Processors Bill Gervasi Technology Analyst, Transmeta...
Low Power Systems Using
Transmeta Crusoe Processors
Bill Gervasi
Technology Analyst, Transmeta
Chairman, JEDEC Memory Parametrics
2
Crusoe 5800 System Architecture
TM5800
CPUP
C1
33
SD
RA
M C
on
tro
ller
DD
R33
3 S
DR
AM
Co
ntr
olle
r
PCI Controller
On-Chip Cache
Path Arbiter
DDR SDRAMPORT
SDR SDRAMPORT
PCI Expansion Bus
Standard system peripherals
Crusoe is a trademark of Transmeta Corp.
Transmeta Crusoe was the first DDR enabled processor
in the industry
3
Advantages of Integrated Memory Control
One less bus to waste power
Low latency to memory after cache miss
No synchronization penalties– Unique source synchronous & true
synchronous memory design– Memory clock domain tied to CPU clock
domain
Aggressive power management coordinated with CPU power states
4
A Brief Tutorial on Power Consumption
Power = CV2f%
Factors:
Capacitance (C)
Voltage (V)
Frequency (f)
Duty cycle (%)
Power states
Keys tolow power design:
Reduce C and V Match f to demand Minimize duty cycle Utilize power states
5
Quiz #1 on CPU Power
Question:
Which Burns More Energy?
1. A 600 MHz CPU2. A 1 GHz CPU
Hint: This is a trick question.
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Answer to Quiz #1
Assume the 600 MHz CPU is a downbin of the 1 GHz CPU
If the task load, such as DVD decode, requires 600 MHz of processing power– The 600 MHz CPU must be maxed out with its
highest core voltage, e.g., 1.2V– The 1 GHz CPU can be throttled to 600 MHz
and can have its core voltage reduced, e.g., 1V
Conclusion: The 1 GHz CPU burns less energy for a given task than the 600 MHz CPU
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The LongRun Philosophy
Use the least energypossible to accomplish
the desired task.
LongRun is a trademark of Transmeta Corp.
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Transmeta Crusoe with LongRun
On Demand processingScale operational frequency onapplication demand– 33 MHz increments from 400 MHz to CPU’s
max frequency– Adjust core voltage to minimum for the desired
target frequency– LongRun events hundreds of times per second
Memory clock speed relative to CPU speed, e.g.:1 GHz CPU 333 MHz DDR or 167 MHz SDR400 MHz CPU 200 MHz DDR or 100 MHz SDR
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CPU Without LongRun Technology
Users must balance choice of CPU speed against decreasing battery life
600MHz
800MHz
1GHz
Battery Life
Energy required per task
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CPU With LongRun Technology
Users will want the highest MHz CPU– Best Performance– Lower Power– Longest battery life
600MHz
800MHz
1GHz
Battery Life
Energy required per task
11
Memory Transition
From SDR to DDR
12
The JEDEC Memory Roadmap
JEDEC roadmap triples GB/s/W with each generation– Power reduction of 30%– Bandwidth doubles
SDR DDR I DDR IISDR DDR I DDR II3.3V 2.5V 1.8V3.3V 2.5V 1.8V
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Power: DDR II vs DDR I vs SDR
Relative GB/s per Watt
PC133
DDR333
“DDR I”
Four times the bandwidth yet half the power!
DDR533
“DDR II”
14
Transmeta’s CPU RoadmapSupports the JEDECMemory Roadmap.
Always has.
15
TM6000x86 System On a Chip128-bit VLIW / CMS 5.x
1 GHzLess Power and Space
Crusoe Processor Roadmap
Crusoe Processor Roadmap
TM5400 / TM5600128-bit VLIW / CMS 4.1
500 - 667 MHz
TM5500 / TM5800128-bit VLIW / CMS 4.2
667 MHz - 1 GHz
Next Generation Crusoe256-bit VLIW / New CMS
2-3x Performance
2000 2001 2002
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TM6000 Single Chip PC
TM6000 Single Chip PC is Ideal for Wireless Internet Devices
Smallest Footprint
Lowest Power
Highest Performance (400 MHz to 1 GHz)
Full x86 Compatibility
Optional Support for External 3D Graphics
PCI Bus
4X USB 1.1
LPC Bus
IDE/DVD/CD-RW
TM6000
AC97 Link
KBC
SMBUS
LVDS24-bit Digital
DDR-33364MB-2GB w/ECC
IDE (Flash or Disk)
Disk Upgrade
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DDR333 Memory Controller• 2.7 GB/s DDR with ECC
Crusoe TM6000 Microprocessor -- x86 System on a Chip
Universal Serial Bus (USB)• 4 Ports OHCI 1.0a
AC-Link Audio/Modem
System Management bus
Low Pin Count bus (LPC)
8 General Purpose I/Os
Legacy PC Peripherals• Dual 8259 Int. Controller• Dual 8237 DMA Controller• 8254 System Timer• 146818 Real Time Clock• 16550 UART
Graphics Controller• 24 bit digital and • LVDS interfaces• Dual Scan LCD and CRT• DVD playback support
PCI Bus Interface
IDE Disk Controller• 2 Channel / 4 DrivesCentral Processor Unit
• 1 GHz • 0.9 - 1.3 volt LongRun• 128-bit VLIW Engine• 512KB L2 Cache
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TM
5800
S
olu
tion
3.6 wattsDVD Play Example:TM5800 Solution CPU+NB = ~1.4 wattsSouthbridge = ~0.7 wattsGraphics = ~1.5 wattsTotal = ~3.6 watts
TM6000 System Level Power Management By integrating the TM6000, LongRun can now be applied to Graphics and Southbridge electronics as well.
TM
6000
S
olu
tion
~2 watts
TM6000 SolutionTotal = ~2.0 watts
-44%
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Summary
Aggressive power management techniques enable new mobile and low power computing markets
It’s a systems level design issue…apply to all subsystems as well
20
Thank You