Download Transmeta Crusoe

Transmeta Crusoe
A revolutionary CPU for mobile
computing
Ashraful Alam
Outline



What is Crusoe?
Why Crusoe?
Crusoe architechture
 128
bit VLIW
 Code morphing technology
 Integrated northbridge
 LongRun technology

Conclusion
What is Crusoe?
A low power consuming x86 processor
 Developed by Transmeta Corporation
 Devoted to fill gap in mobile CPU market
 Developed from scratch
 Hybrid hardware-software design
 Efficient computing

Why Crusoe
Lighter is better
 Low power consumption
 Fan less systems
 High mobility without compromise

Targeted Market
Wireless computing
 Silent PC
 Home theatre PC
 Portable pc
 Dense Server Cluster

Crusoe Product Line
All power requirement includes Northbridge power.
The SE versions of Crusoe are designed for Embedded systems
Model
TM 5900
TM59SE
TM 5700
TM 57SE
TM 5800
TM 58SE
Clock speed
667-1000Mhz
667-933 MHz
667-800 Mhz
667 Mhz
667 – 1000 MHz
800/933 MHz
L1 Cache
128 KB
128 KB
128 KB
128 KB
128 KB
128 KB
L2 Cache
512 KB
512 KB
256 KB
256 KB
512 KB
512 KB
Max TDP
6.5-9.5 W
6.8-9.0 W
5-6.6 W
5.1W
< 6.5 W
6.8-9.0 W
Table: Family of Crusoe processors
[source: http://www.transmeta.com/crusoe/specs.html]
Max temp.
100C Tj
100C Tj
100C Tj
100C Tj
100C Tj
100C Tj
Crusoe Architechture
128 Bit Very Large Instruction Word Issue
 Hybrid computing aka Code morphing™
 Integrated Northbridge on die
 LongRun™ Technology

128 Bit VLIW Engine
4 instruction issue
 Fewer transistors = less power
consumption
 Introducing code morphing™
 Large 512kb cache

128bit VLIW (cont.)

Crusoe executes like a superscalar
processor
Source: http://arstechnica.com/articles/paedia/cpu/crusoe.ars/3
Code Morphing
Software layer around the hardware
 x86 compatibility without complexity
 Reduced transistors
 Statistical optimization
 Downloadable hardware upgrade!

Code Morphing (cont.)

Code morphing software creates a bridge between x86 software and
Crusoe
[Source: http://www.transmeta.com/crusoe/codemorphing.html]
Code Morphing (cont.)

Blue represents hardware in silicon
 Yellow represents software layer
Source: http://arstechnica.com/articles/paedia/cpu/crusoe.ars/2
Code Morphing (cont.)

2 parts of the code morphing software:
 Interpreter
Interprets x86 code
 Filters infrequent code for interpretation only
 Gathers statistical data

 Translator
Recompiles frequently used code for optimization
 Stores translated code into translation cache

Integrated Northbridge
On die memory controller
 On die PCI bus controller
 Serial ROM controller
 Benefits

 Reduced
power consumption
 Compact system design
LongRun™ Technology
LongRun technology is tightly coupled with
code morphing software
 Performs two task:

 Power
management
 Thermal management
LongRun Power Management
Dynamically adjust both core voltage and
clock speed
 Cubic power requirement reduction

 Power
= (Capacitance * freq * voltage^2)/2
 Most conventional CPU can only adjust
frequency
* AMD’s “cool N quiet” technology adjusts both
voltage and clock frequency
Power Management (cont.)

If Idle time is detected, processor may reduce
voltage/frequency to reduce power usage
Power Management (cont.)
Figure: Dynamic frequency scaling
Power management heuristic – goal is to eliminate CPU
sleep time as much possible
[source: LongRun Power management white paper]
Power Management (cont.)
Figure: Voltage scaling
Voltage and frequency scale can be done upto 200
time/sec
[source: LongRun Power management white paper]
Thermal Management
Coupled with code morphing software to
throttle CPU
 Efficient computing in low temperature

 Dynamically
reduces voltage/frequency
 Does not force CPU to sleep phase to reduce
heat
 Provides more performance in higher
temperature or same performance in lower
temperature.
Thermal Management (cont.)

P3 and Crusoe running DVD movie
 Crusoe TM5400 requires no active cooling
Conclusion
Revolutionary hybrid design
 Efficient use of instruction optimization
 Reduced power consumption
 Leads the path in efficient computing
 Great choice for mobile computing
 Great choice for systems where low power
processing is required

Sources
The Technology Behind Crusoe™
Processors White Paper by Transmeta
Corporation
 Crusoe™ LongRun™ Power
Management White Paper by Transmeta
Corporation
 Crusoe Explored by John Stokes

http://arstechnica.com/articles/paedia/cpu/crusoe.ars/1