Re: [myhdl-list] Convertible records

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

On 9/2/2011 1:57 PM, Sébastien Bourdeauducq wrote:
> On 09/02/2011 08:15 PM, Jan Langer wrote:
>> maybe it would be a good idea to let the converter "ask" the class how
>> it wants to be converted
>
> Can't you infer the list of signals to convert from which ones get
> actually used?
>
> What would be good imo (but with my limited knowledge of Python, I don't
> know if it's possible) is to simply name signal objects in the generated
> HDL according to how they were created. For example:
>
> class some_class()
> 	def __init__(x):
> 		self.some_signal = x

I think, similar to the previous examples, we want the class with 
signals to be declarative and not dynamically building.  Not that they 
can't be, but for a start should limit the discussion to building 
objects similar to VHDL record and SV struct. (??)

The SignalStruct is a basic container of Signals.  At least for 
conversion, modeling you can do all kinds of cool stuff.  If you 
encapsulate an interface (collection of signals) into a class 
(SignalStruct) you can build in balun circuits :)  Think they are also 
know as transactors or interfaces abstractions.


> (...)
> b = Signal(bool(0))
> some_object = some_class(b)
> toVerilog(some_object.method)
>    =>  gives a signal named "b"
>
> class some_class()
> 	def __init__():
> 		self.some_signal = Signal(bool(0))
> (...)
> some_object = some_class()
> toVerilog(some_object.method)
>    =>  gives a signal named "some_object_some_signal"
>
> (We should adopt a better naming scheme to guarantee the absence of
> collisions, but you get the idea)
>
> This way (I believe) we could happily play with Python objects and still
> make nicely convertible/synthesizable code.
>
> For ports, we can maybe give references to signal objects we want
> exported to the conversion functions.

I think the port can be the class object, for the previous example

   bus1 = MyBus()
   bus2 = MyBus()
   arb  = MyBusArb(bus1, bus2)  # <-- RTL module

The converter will check the types, and will be ok with the port types 
because it will know how to handle them.

Regards,
Chris