Re: [f-cpu] the wrong way (of floating point and so on)

[Ben Franchuk <bfranchuk@jetnet.ab.ca>]

> I think we should forget to trace the way to include floating point now.
> Why?
> IMHO there are too many tasks to do, which are more important than
> thinking about floating point units. First, we should have a working
> "simple" F-CPU, not more nor less.
> Second, a FPU was declared as an optionally unit,
> Floating-point-operations are rare and should be emulated in an
> intelligent way (software) to use the full power of F-CPU's
> SIMD-capabilities
> Last, If we are better in designing units and we have a real (!) F-CPU we
> can easily extend the core with an existing FPU, I think.
> 
> In my mind I do not realisize how you will design the scoreboard and the
> shifting unit in a possible way or I misunderstood anything.
> 
> In my opinion we need in near future a working CPU to get and hold a good
> developer-basis, and to make tests in reality not in emulations only.
> 
> Because we can compose a set of FPGAs (Altera and Co.) to load and emulate
> the CPU, we should go in this direction, to make FC0 to that what it is,
> "a proof of concept".
> 
> I am in right?

I suspect it better to design for the floating point unit now
but leave it out when on the first revision of the cpu design.
Otherwise you could have a large problem trying to "patch" the
floating point unit to the cpu. Say for example you wanted a few
extra bits used just by floating registers you may use 67 bits
for all the registers?This could have a large impact if you all
ready designed 64 bit registers.
Ben.
PS. I suspect using low cost (slow) Altera parts you will have a
clock rate about 8-16 Mhz.

-- 
Standard Disclaimer : 97% speculation 2% bad grammar 1% facts.
"Pre-historic Cpu's" http://www.jetnet.ab.ca/users/bfranchuk
Now with schematics.
*************************************************************
To unsubscribe, send an e-mail to majordomo@seul.org with
unsubscribe f-cpu       in the body. http://f-cpu.seul.org/