[usb] Endpoint Numbers

[Rudolf Usselmann <rudi@asics.ws>]

Looks like I'm dropping the idea of a linked list in memory to define
endpoints. I will instead allow at compile (synthesis) time to define
how many endpoints an implementation has.

Now, I'm thinking that any given endpoint that is instantiated at
compile time, can perform only one of CONTROL, IN or OUT functions,
which can be selected by the software of the function. This will
make the design very simple.

Now I have two questions:

1) Since the endpoints are instantiated at synthesis time, I can
set the endpoint numbers at that time. However, this would then
make it impossible to have an endpoint 3 (for example) that has CONTROL,
IN and OUT operations at the same time. So what I can do, is to make
the actual USB endpoint number programmable by the functions controller.
So one could set up 3 endpoint 5s, one for each operation.

What do you guys think ?

2) Considering the above scheme, how many (maximum) endpoints should I
 support ?

Thanks for your help guys and gals !


rudi