1. Crusoe Processor
Seminar Guide: By: -
Prof. H. S. Kulkarni Ashish

2. Outline What is Crusoe? Crusoe architecture 128 bit VLIW
Code morphing technology
Integrated Northbridge
Longrun technology
Advantages
Disadvntages
Conclusion

3. What is Crusoe? Developed by Transmeta Corporation
A low power consuming x86 processor
Devoted to fill gap in mobile CPU market
Hybrid hardware-software design
Efficient computing

4. Why Crusoe? Lighter is better Low power consumption Fan less systems
High mobility without compromise

5. Targeted Market Mobile computing Silent PC Home theatre PC Portable PC
Dense Server Cluster

6. Crusoe Product Line All power requirement includes Northbridge power.
The SE versions of Crusoe are designed for Embedded systems
Table: Family of Crusoe processors
[source:

7. Crusoe Architecture 128 Bit Very Large Instruction Word Issue (VLWI)
Hybrid computing aka Code morphing
Integrated Northbridge on die
LongRun Technology

8. Crusoe Architecture (cont.)

9. 128 Bit VLIW Engine 4 instruction issue
Fewer transistors = less power consumption
Introducing code morphing
Large 512kb cache

10. [Source: http://arstechnica.com/articles/paedia/cpu/crusoe.ars/3]
128bit VLIW (cont.)
Crusoe executes like a superscalar processor
[Source:

11. Code Morphing Software layer around the hardware
x86 compatibility without complexity
Reduced transistors
Statistical optimization
Downloadable hardware upgrade!

12. [Source: http://www.transmeta.com/crusoe/codemorphing.html]
Code Morphing (cont.)
Code morphing software creates a bridge between x86 software and Crusoe
[Source:

13. Code Morphing (cont.) Blue represents hardware in silicon
Yellow represents software layer
[Source:

14. Code Morphing (cont.) 2 parts of the code morphing software:
Interpreter
Interprets x86 code
Filters infrequent code for interpretation only
Translator
Recompiles frequently used code for optimization
Stores translated code into translation cache

15. Crusoe Software Hierarchy

16. Integrated Northbridge
On die memory controller
On die PCI bus controller
Serial ROM controller
Benefits
Reduced power consumption
Compact system design

17. LongRun™ Technology
LongRun technology is tightly coupled with code morphing software
Performs two task:
Power management
Thermal management

18. 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

19. Power Management (cont.)

20. Power Management (cont.)
Power management heuristic – goal is to eliminate CPU sleep time as much possible
If Idle time is detected, processor may reduce voltage/frequency to reduce power usage
Voltage and frequency scale can be done upto 200 time/sec

21. 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.

22. Thermal Management (cont.)
P3 and Crusoe running DVD movie
Crusoe TM5400 requires no active cooling

23. Advantages Lighter is better Low power consumption Fan less systems
High mobility without compromise

24. Disadvantages
Code optimization doesn’t start until a block of code has been executed.
Code translation requires clock cycles which could otherwise be used in performing application computation.

25. 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

26. References
The Technology Behind Crusoe™ Processors White Paper by Transmeta Corporation
Crusoe™ LongRun™ Power Management White Paper by Transmeta Corporation
Crusoe Explored by John Stokes