Re: [myhdl-list] What is not convertible.

[Jan D. <ja...@ja...>]

On 05/02/2012 06:49 PM, Christopher Lozinski wrote:
> The manual has a great section on the convertible subset.  For those
> guys who are design engineers, it totally makes sense.  For those of us
> who are newer to digital circuit design, it is not quite clear what is
> not convertible.
>
> So I wrote up a section on my wiki. What is not convertible.
>
> wiki.myhdlclass.com:8080/WhatIsNotConvertible
>
> Really what this is telling software developers is what you cannot do at
> the RTL modeling level.

"Things should be kept as simple as possible, but not simpler." (Einstein)

You try to make things simpler than they really are. The result is a
page full of errors and inaccuracies that would greatly increase confusion.

* The convertible subset is not the same as the RTL level. It is much
broader, the intention is that it is never an obstruction for synthesis.
But don't think for a moment that anything that converts is also
synthesizable. In fact, it doesn't teach you anything about the RTL
level.

* Python objects not convertible? Well, isn't anything an object
in Python - some of those surely are convertible.

* Things outside a decorator not convertible? Well, be careful with
the message here. Conversion works after elaboration, which means
you can do all kinds of crazy things outside decorated functions,
without conversion restrictions.

* tuples of.. and list of ... Well, one should check the table to
learn about restrictions.

Note that my post of corrections is longer than the page
your wrote. This really takes up a lot of energy.

-- 
Jan Decaluwe - Resources bvba - http://www.jandecaluwe.com
     Python as a HDL: http://www.myhdl.org
     VHDL development, the modern way: http://www.sigasi.com
     World-class digital design: http://www.easics.com