1

Crusoe Processor

Seminar Guide: - By: -

Prof. H. S. Kulkarni Ashish

2

OutlineWhat is Crusoe?Crusoe architecture

128 bit VLIWCode morphing technologyIntegrated NorthbridgeLongrun technology

AdvantagesDisadvntagesConclusion

3

What is Crusoe?Developed by Transmeta CorporationA low power consuming x86 processorDevoted to fill gap in mobile CPU marketHybrid hardware-software designEfficient computing

4

Why Crusoe?Lighter is betterLow power consumptionFan less systemsHigh mobility without compromise

5

Targeted MarketMobile computingSilent PCHome theatre PCPortable PCDense Server Cluster

6

Crusoe Product LineAll power requirement includes Northbridge power.

The SE versions of Crusoe are designed for Embedded systems

Model Clock speed L1 Cache L2 Cache Max TDP Max temp. TM 5900 667-1000Mhz 128 KB 512 KB 6.5-9.5 W 100C Tj TM59SE 667-933 MHz 128 KB 512 KB 6.8-9.0 W 100C Tj TM 5700 667-800 Mhz 128 KB 256 KB 5-6.6 W 100C Tj TM 57SE 667 Mhz 128 KB 256 KB 5.1W 100C Tj TM 5800 667 – 1000 MHz 128 KB 512 KB < 6.5 W 100C Tj TM 58SE 800/933 MHz 128 KB 512 KB 6.8-9.0 W 100C Tj

Table: Family of Crusoe processors

[source: http://www.transmeta.com/crusoe/specs.html]

7

Crusoe Architecture128 Bit Very Large Instruction Word Issue (VLWI)Hybrid computing aka Code morphingIntegrated Northbridge on dieLongRun Technology

8

Crusoe Architecture (cont.)

9

128 Bit VLIW Engine4 instruction issueFewer transistors = less power consumptionIntroducing code morphingLarge 512kb cache

10

128bit VLIW (cont.)

Crusoe executes like a superscalar processor

[Source: http://arstechnica.com/articles/paedia/cpu/crusoe.ars/3]

11

Code MorphingSoftware layer around the hardwarex86 compatibility without complexity Reduced transistorsStatistical optimizationDownloadable hardware upgrade!

12

Code Morphing (cont.)

Code morphing software creates a bridge between x86 software and Crusoe

[Source: http://www.transmeta.com/crusoe/codemorphing.html]

13

Code Morphing (cont.)

Blue represents hardware in siliconYellow represents software layer

[Source: http://arstechnica.com/articles/paedia/cpu/crusoe.ars/2]

14

Code Morphing (cont.)2 parts of the code morphing software:

Interpreter Interprets x86 codeFilters infrequent code for interpretation only

TranslatorRecompiles frequently used code for

optimizationStores translated code into translation cache

15

Crusoe Software Hierarchy

16

Integrated NorthbridgeOn die memory controllerOn die PCI bus controllerSerial ROM controllerBenefits

Reduced power consumptionCompact system design

17

LongRun™ TechnologyLongRun technology is tightly coupled

with code morphing softwarePerforms two task:

Power managementThermal management

18

LongRun Power ManagementDynamically 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 ManagementCoupled with code morphing software

to throttle CPUEfficient 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 movieCrusoe TM5400 requires no active

cooling

23

AdvantagesLighter is betterLow power consumptionFan less systemsHigh mobility without compromise

24

DisadvantagesCode 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

ConclusionRevolutionary hybrid designEfficient use of instruction optimizationReduced power consumptionLeads the path in efficient computingGreat choice for mobile computingGreat choice for systems where low

power processing is required

26

ReferencesThe 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