[virtmach] Transmeta Crusoe

David Rush kumo@bellsouth.net
03 Feb 2000 15:13:58 +0000


"Peter William Lount" <peter@smalltalk.org> writes:
> >From what I've heard and read Transmeta will not be opening up the
> internals of their VLIW CPUs to outsiders. 

Well, now I decided that I had to finally take a look at there web
site. I'm not surprised that they won't open things up. Has the
definition of VLIW architecture changed while I wasn't looking? ISTR,
some late-80s CPU that had that moniker attached: At the time it
appeared to mean a fairly neat approach to fine-grained parallelism.

The 'Bulldog' (IIRC) basic ran anywhere from 4 to 16 CPUs in parallel
on one chip, splitting the instruction stream at each branch
instruction, *executing both branches* until it was clear which one
was actually the correct one for the data. I know this sounds
confusing, but they claimed that they had a very smart compiler
technology behind this that made it all automagically work out.

Transmeta's solution sounds more like a return to microcoded CPUs.

> They say that they are
> keeping it internal because they don't want to have to support "legacy" for
> their own chips and that x86 legacy is bad enough... ;--).

Or maybe they're embarassed (or, more charitably, they don't want to
give up a technology edge), although I always thought that microcode
was too much of a good idea to go to waste. It's neat to see an
economic justification for it to arise again. Plus ca change...

> It's also interesting to note that they have an awesome opportunity to
> provide "low level debugging" tools for Operating System and Virtual
> Machine authors. Linus said that it's great for programming Linux with
> because of the debugging environment they have constructed internally!
> However, it won't be released. Lets get them to release it!

If they're going to sell the CPUs, they'll sell the debuggers
eventually. Just wait.

david rush
-- 
>From the start...the flute has been associated with pure (some might
say impure) energy. Its sound releases something naturally untamed, as
if a squirrel were let loose in a church." --Seamus Heaney