Re: [fpu] Current progress

[Usef Saiful-Ulum <usef@vlsi.itb.ac.id>]

On Wed, 12 Apr 2000, Jamil Khatib wrote:

> Regarding some information,
> I updated the FPU page in opencores site you can check for some links
> I want to add a link for the x86 architecture http://www.x86.org we can find
> some information about the coprocssor.
> 
> Where can I find the OR1K interface for the FPU. 

I think this is still under development, so actually we can define the
coprocessor interface. What have been specified is 16x64-bit FPR.

> I think we can should be able
> to build this FPU to be able to run as a stand alone core and so to be plugged
> to any other processor. what do you think?

if we want to develop a stand alone core we should avoid "bus watching"
mechanism (ARM style) because the coprocessor should not be attached to
OR1K native bus. I'm not sure what was the main advantage of having this 
processor-independent FPU core since otherwise, in my opinion, it would
simplify the design of the portion of the interface and fasten the
coprocessor-register transfer instruction.

If we want to optimized for speed of FP operation then I think we should
develop a parallel pipelined FPU, AMD K7 using this style. Or maybe you
have other ideas to raise the FPU performance?

Best regards,

Usef