Re: [myhdl-list] AttributeError in 0.8-dev but not in 0.7

[Per K. <bas...@gm...>]

Hi!
I have dug a little deeper, and it has to do with using Signal(bool(False))
and Signal(intbv(0)[1:0]).
If I use only the latter and make all comparisons explicit ("if flag==1"
instead of just "if flag") the AttributeError goes away.
I have also seen that even if I don't get the attribute error there are
simulation mismatches between the verilog and the myhdl when intbv and bool
are mixed.

I've seen this discussed on the boards before, and I think it is obvious
that we need to support "if not flag:"-like syntax. It makes the code
easier to read, and it works in both python and verilog.
/Per



On Wed, Jan 23, 2013 at 11:15 PM, Per Karlsson <bas...@gm...>wrote:

> Hi!
> There is probably something fishy about the lines 184-192 in _Signal.py in
> 0.8dev
> With 0.8-dev I get:
>     File [...]/_Signal.py", line 195, in _update
>      self._val._val = next._val
> AttributeError: 'bool' object has no attribute '_val'
> With 0.7 it works fine. Also toVerilog works fine in both 0.7 and 0.8-dev
> and iverilog cosimulation passes.
>
> I have not been (immediately) able to reproduce the error outside of the
> project (which I'm afraid I can't show you), but I have pinpointed the
> lines that cause the error. They are perfectly ordinary. (if b==0: a.next =
> 1 basically)
>
> When I debug I see that 'next' is a bool and val is an 'intbv', whereas
> normally both are 'intbv'.
>
> I know this is a bit vague, but perhaps Jan can recall what he was doing
> in May 2011 and figure it out. :)
>  /Per
>
> ps. Anyone got any general tips for myhdl debugging?
>