The optimizations are thorough enough that, in some instances, twenty x86 instructions can be reduced to ten Crusoe instructions. These optimizations are then stored for later use to speed identical tasks up in the future. A Transmeta representative even went so far to say that coding software in native Crusoe code does not pay off since the software optimizations the code morphing software applies to x86 code work so well.
The morphing software resides in flash ROMs and is the first software the Crusoe CPU loads at startup via the previously mentioned serial I/O port. Translated code as well as the morphing software reside in approximately 16MB of system memory, memory which is invisible to x86 software.
Once the morphing software is loaded, the Crusoe's VLIW architecture is invisible to all x86 programs and hardware around it. So most any x86 OS, including Windows, Linux and BeOS, can run. The x86 support is so transparent, even stock PC BIOS and southbridge chips (the southbridge supplies I/O such as USB, serial ports, IDE and more) can be used.
According to Transmeta, approximately 3/4 of the Crusoe is software and 1/4 is hardware. By having the x86 instruction set in software, Transmeta was able to design a streamlined, small, low-power, low-heat CPU. They didn't have to waste space on power hungry and heat producing gates for complex work-arounds needed to increase CPU speed while keeping backwards compatibility.
By having morphing software between the CPU and other software, Transmeta can be much more aggressive in their chip designs and not have to worry about backward compatibility. They just need to rewrite the morphing software for every new CPU.
They can even make drastic changes to their chip architecture yet still allow x86 software to run without trouble. And by having the x86 instruction set in software, Transmeta is able to fix bugs via Internet downloadable flash ROM upgrades.
The Code Morphing process and software CPU idea are interesting to say the least. A Transmeta representative stated they felt that, five years from now, all other CPU makers would be using a similar design. Intel's IA-64 uses an EPIC instruction set, which is similar to VLIW, but we don't believe Intel currently has plans to use something like Code Morphing with the IA-64 platform.
Whether Code Morphing is the way of the future or not remains to be seen. Intel and AMD have taken CISC far past the point many thought it could be taken. We see no reason not to expect them to take it further and ignore innovations like Transmeta's system.
Also, we were skeptical when Transmeta said that native Crusoe code doesn't pay off. While real-time optimizations are a great thing, aggressive compiler optimizations work wonderfully and don't require extra CPU power. Maybe native Crusoe code would pay off if they had better developed native compilers?