[Open-graphics] VCS status

[Timothy Normand Miller]

On 1/6/08, Petter Urkedal <urkedal at nbi.dk> wrote:
> I'll make room for the new instruction by using the same ALU operand
> code for all three shift operations, move y-reg bits to the lower end
> of y-immediates, and use the second and third highest immediate bit to
> select the mode of the shifter:
>
>                                 16 | 15    14,13           4   0
>   mode | op | imm? | z-reg | x-reg |sign shift-mode        y-reg
>                                    |<--------- y-imm ---------->

Looks good.  I'm still trying to work out how it works from the code.
Some comments that enumerate the various modes would help.

> I consider using the attached rot/shift module.  I'm not sure if this is
> a good idea, but I force the synthesizer to make it O(log(N)) depth.
> The three operations are combined to allow sharing the most expensive
> part.  Should I add the full license text and put it in rtl/lib?
> Otherwise, I'll insert it in oga1hq.v.

It's very short and very HQ-specific.  I'd just put it into oga1hq.v.

Thanks.


-- 
Timothy Normand Miller
http://www.cse.ohio-state.edu/~millerti
Open Graphics Project