Re: [myhdl-list] intbv improvement?

[Neal B. <ndb...@gm...>]

Jan Decaluwe wrote:

> Neal Becker wrote:
>> I would find this addition to the intbv constructor helpful:
>> 
>> class intbv(object):
>>     __slots__ = ('_val', '_min', '_max', '_nrbits')
>>     
>>     def __init__(self, val=None, min=None, max=None, _nrbits=0,
>> is_signed=False):
>>         if _nrbits:
>>             if (is_signed):
>>                self._min = -1 << (_nrbits-1)
>>                self._max = ~(-1 << (_nrbits-1))
>>             else:
>>               self._min = 0
>>               self._max = 2**_nrbits
> 
> I infer that you want to use _nrbits as an end user also?
> This is not how the type is set up. _nrbits is intended
> to be a private parameter of the constructor for internal
> use.
> 
> One of the goals of intbv is to get rid of unsigned/signed
> thinking as much as possible, and push the use of fine-grained
> range control as high-level alternative.
> (I'm actually writing a paper about this, almost finished.)
> 
> Jan
> 

I want to make sure my value is converted to verilog signed.  AFAICT, the 
only way I have now to do this is with intbv specifying min and max, rather 
than nrbits?  That's OK, but a little inconvenient.