2. Contents
Introduction
Crusoe processor VLIW hardware
Code morphing software
Long run power management
Crusoe processor architecture
Conclusion
3. Features
Mobile computing devices like laptops ,
webslates ¬ebook PCs are becoming
common
Heart of every PC is MICROPROCESSOR.
The mobile computing market has never had a
microprocessor specially designed for it
4. Drawbacks
Consumes lots of power
They get very hot
Needs a cooling fan
When you are on go, a power hungry
processor
-- run out of power before you’ve
finished
--run more slowly and lose application
performance
5. This makes the resultant mobile
computer:
Bigger
Clunker
Noisier
6. Crusoe processor
Designed specially for the mobile computing
market.
Developed by small silicon valley startup
company called Transmeta Corp
Easily understood from simple sketch of the
processor architecture called AMOEBA
7. Crusoe processor
Hybrid processor
It has a software part and a hardware part with
the software part layer surrounding the
hardware unit
128 – bit microprocessor
Fabricated on CMOS process
Based on technique called VLIW
8. Crusoe processor
It uses Transmeta’s two patent
technologies
Code morphing software
Long run power management
10. Crusoe processor VLIW
hardware
Very Long Instruction Word
Combines multiple standard instructions into
one long instruction word
Explicit parallelism
Trace scheduling
Dynamic scheduling
13. Code morphing software
Dynamic translation system
Program that compiles instruction set
architecture( X86 target ISA) into instructions
for another ISA (the VLIW host ISA)
Resides in ROM
First program to start executing when the
processor boots
14. Decoding and Scheduling
Code morphing can translate an entire group
of x86 instructions at once
Transmeta’s software translates instructions
once, saving the resulting translation in a
translation cache
The next time the x86 code is executed the
system skips the translation step and directly
executes the existing optimized translation
15. Decoding and Scheduling
The code morphing approach can amortize the
cost of translation over many
executions, allowing it to use much more
sophisticated translation and scheduling
algorithms
Speeds up execution while at the same time
reducing power
16. Caching
Resides in a separate memory space that is
inaccessible to x86 code
Size of memory space can be set at boot time
The crusoe processor’s approach of caching
translations delivers excellent performance in
real – life situations
17. Filtering
The code morphing software includes in its
arsenal a wide choice of execution modes
A sophisticated set of heuristics helps choose
among these execution modes based on
dynamic feedback information gathered during
actual execution of the code.
18. Prediction and Path Selection
The micro-op translation adds at least one
pipeline stage and requires the decoder to call
a microcode routine to translate some of the
most complex x86 instructions
Implementing the equivalent of that fronted
translation in software saves Transmeta a
great deal of control logic and simplifies the
design of chips
It also allows to patch some bugs in software
19. LONG RUN POWER
MANAGEMENT
The TM5600 can adjust its power consumption
without turning itself off
It can adjust its clock frequency on the fly
It does so quick and without requiring an
operating system reboot or having to go
through a slow sequence of suspending to and
restarting from RAM