Crusoe

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For the fictional character, see Robinson Crusoe.

In electronics, Crusoe is a family of microprocessors from Transmeta. They use a VLIW hardware "core", upon which runs a software abstraction layer, or virtual machine, known as the Code Morphing Software (CMS). The CMS translates machine code instructions received from programs running on the chip into native instructions for the core. In this way, the chips can emulate the instruction set of other computer architectures.

Currently, this is used to allow the chips to emulate the Intel x86 instruction set. In theory, it is possible for the CMS to be modified to handle other instruction streams (i.e. to emulate other microprocessors).

The addition of an abstraction layer between the x86 instruction stream and the hardware means that the hardware architecture can change without breaking compatibility, just by modifying the CMS. For example Efficeon, the second-generation Crusoe, has a 256-bit-wide VLIW core versus 128-bit in the first generation.

Crusoe performs in software some of the functionality traditionally implemented in hardware (e.g. instruction re-ordering), resulting in simpler hardware with fewer transistors. The relative simplicity of the hardware means that Crusoe consumes less power (and therefore generates less heat) than other x86-compatible microprocessors running at the same frequency.

The name is taken from the novel Robinson Crusoe.

[edit] Products

Compaq TC1000
Compaq T5515 Thin Client
ECS EZ-Tablet EZ30
Flybook
Fujitsu LifeBook P1120
HP Compaq t5700 Thin Client
NEC PowerMate Eco
NEC Versa DayLite/UltraLite
Sharp Actius/Mebius MM10
Sony Vaio PCG-U1 and PCG-U3
TDV Vison V800XPT Tablet
OQO Model 01 and 01+

[edit] References

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