Ethernet & FPGA

Hi...

i'll write my bachelor thesis about the implementation of ethernet and 
possible tcp/ip layers in an fpga. does someone have experience doing 
it? especially using open source ip cores like the ethernet MAC core 
from opencores.org? would be nice if someone could share their 
experience. another point is the implementation of tcp/ip. does it make 
sense to do it all in hardware or is it simpler to run a processor core 
on the fpga and then implement the tcp/ip layers using a highlevel 
language like C? i gotta stress that the aim is initially to build an 
runnable ethernet core and then implement the data transfer step by step

TIA

Stefan

>i'll write my bachelor thesis about the implementation of ethernet and 
>possible tcp/ip layers in an fpga. does someone have experience doing 
>it? especially using open source ip cores like the ethernet MAC core 
>from opencores.org? would be nice if someone could share their 
>experience. another point is the implementation of tcp/ip. does it make 
>sense to do it all in hardware or is it simpler to run a processor core 
>on the fpga and then implement the tcp/ip layers using a highlevel 
>language like C? i gotta stress that the aim is initially to build an 
>runnable ethernet core and then implement the data transfer step by step

You can do very simple protocols without much software, but it's
still simpler to think of it as software.

Consider something like a data recording setup.  You send it a UDP packet
and it returns the answer.  You don't need a routing layer since you
send it back where it came from - just swap a few header fields.
(But watch out for the broadcase case.)

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Hi Stefan,

Stefan Kopetsch wrote:

> Hi...
> 
> i'll write my bachelor thesis about the implementation of ethernet and 
> possible tcp/ip layers in an fpga. does someone have experience doing 
> it? especially using open source ip cores like the ethernet MAC core 
> from opencores.org? would be nice if someone could share their 
> experience. another point is the implementation of tcp/ip. does it make 
> sense to do it all in hardware or is it simpler to run a processor core 
> on the fpga and then implement the tcp/ip layers using a highlevel 
> language like C? i gotta stress that the aim is initially to build an 
> runnable ethernet core and then implement the data transfer step by step
> 
> TIA
> 
> Stefan

I have been looking into hardware implemented tcp/ip chips a year or two 
ago for an embedded project. I was intrigued by the idea not to have to 
bother the processor with the tcp/ip stack. I found only two vendors at 
that time and one of them phased their chip already out. One issue I 
found in the other chip was, that it only could handle four tcp 
connections. Granted it still provided access to the ethernet layer, 
which would allow a connected processor to implement a tcp/ip stack, but 
that defeats the purpose of the hardware stacks in the first place.

If you don't have any requirements concerning the tcp/ip layer I guess 
the question will be what do you like to do better, implement a 
processor core in hardware and the tcp/ip stack in software or do the 
tcp/ip stack in hardware. Which brings up the questions what are you 
allowed to take as available ip and what do you have to do by yourself?

With the uClinux running on the OpenRisc and the ethernet core you will 
find, I believe (haven't tested it), a running system with ethernet and 
tcp/ip stack in software on open cores.

Guenter