Re: [myhdl-list] fixbv to current version of myhdl

[Christopher F. <chr...@gm...>]

On 5/2/15 11:27 AM, Henry Gomersall wrote:
> On 02/05/15 16:47, Christopher Felton wrote:
>> On 5/2/15 8:55 AM, Edward Vidal wrote:
>>>> Chris,
>>>> Athttp://dev.myhdl.org/meps/mep-111.html
>>>> Limitations no resize (function yet).
>>>> Is this still true?
>> There is a resize function but it is not convertible
>> at this point.  I can make a convertible version but
>> I didn't like how it worked out, been experimenting
>> with other methods.  The existing resize function
>> can be used for modeling and testing at this point.
>>
>
> How does it work?

Here is the `model` how I thought it should
work:
https://github.com/cfelton/myhdl/blob/mep111_fixbv/myhdl/_resize.py

>
> I've been playing with the routines in flopoco
> (https://gforge.inria.fr/scm/?group_id=1030), which (among other nicely
> portable tools) has a nice tool for resizing - actually it's a zero
> counter and a shift left, so the essence of a resize.

I am not familiar with flopoco but someone else
mentioned it on IRC as well.  I will look at it
when I get a chance :)

Creating the resize for a given set of types isn't
too difficult.  The difficulty is having a single
resize function that can accept any type.

>
> It's the next thing I'm going to be implementing so it would be great to
> combine effort on this. I'm not currently using fixbv, but a kind of
> meta type of an intbv and a separate exponent.

The `fixbv` uses `intbv` as the base class.  There
are multiple mailing-list conversations about the
`fixbv`:

http://article.gmane.org/gmane.comp.python.myhdl/3242/match=fixbv
http://article.gmane.org/gmane.comp.python.myhdl/3265/match=fixbv
http://article.gmane.org/gmane.comp.python.myhdl/3385/match=fixbv
http://article.gmane.org/gmane.comp.python.myhdl/3412/match=fixbv

(I see I didn't follow-up on your previous inquire
into MEP111 and resize, doh:
http://thread.gmane.org/gmane.comp.python.myhdl/3773/focus=3775 )

Regards,
Chris