Re: [myhdl-list] Floating Point Libraries

[Tom D. <td...@di...>]

> Actually I believe there are many good applications for
> "hierarchy" in signals, but I don't think this particular
> case is one.
>
> Before continuing, let me stress once more a point which
> is missed all the time. Everything that is being talked
> about, no matter how complex, can being done in MyHDL -
> the modeling language today. That is not the problem.
>
> The problem is conversion. We need it for the things
> that have to get implemented, but I'm finding it hard.
> For other parts in MyHDL, we can reuse the python
> interpreter. For conversion, we write a compiler
> ourselves. The biggest problem is that for anything
> that we want to support, we have to find and implement
> a meaningful mapping in a much less capable language
> such as Verilog.
>
> Once again: in MyHDL modeling you can do anything you
> want. There is nothing that prevents us from experimenting
> with the type of interface we would like to have,
> and then see if and how we could support it in
> the conversion.
>

I agree that this is only an issue with conversion. And I would also 
add, it is only an issue at the top module level.

The simple solution I use is make a wrapper for the top level I/O. 
Honestly a couple of lines of python code. Like this:

     C = cordic.cordic(type=cordic.MAG)

     # must have intbv at top to make Verilog, so need wrapper
     def cordic_top(mag,in_r,in_i,ov,clk,r,iv) :
       inC = cplx.cplx(in_r,in_i)

       CM0 = C.logic(mag,inC,ov,clk,r,iv)
       return CM0

cplx is just a class that maintains the real and imaginary of whatever 
type you are using. Typically I would have two of some other data type, 
fixed, float or int.

cordic is a class that contains the logic and models for the module.

Now I don't know how conversion works and frankly it is like magic to 
me. I was just saying if we wanted to fix this, my idea (for what it's 
worth) would be to allow a class to inherit a base set of methods that 
conversion knew about. Then change the ones needed to simplify your life.

My assumption is that the Signal class contains some conversion 
information.