[lowrisc-dev] Re: Ethernet Support on the rocket FPGA
jamey.hicks at gmail.com
Tue Apr 19 14:51:37 BST 2016
I've connected Bluespec's RISC-V implementation to the Xilinx 1Gbit/s
The biggest difference between connecting a UART and connecting an ethernet
is that ethernet generally requires DMA connected to the processor memory
fabric (nasti in this case).
I highly recommend starting with an ethernet core, device driver, and
configuration information that you know is working with a different
processor architecture before trying to get it working with RISC-V.
On Mon, Apr 18, 2016 at 5:44 AM Wei Song <ws327 at cam.ac.uk> wrote:
> Hello Pawan,
> I do not think I can provide you more information than what Stefan has
> already shared.
> In a tethered system, the ethernet is connected to the companion ARM core.
> In a untethered system, the ethernet needs to be connected to the
> Rocket-chip directly using its nasti interconnect.
> There might be a need for DMA though.
> Both of them need some serious work in software perhaps to bring up the
> Frankly speaking, I have not tried to connect an ethernet myself, which
> Stefan actually did.
> On 17/04/2016 21:34, Pawan Reddy Sibbala wrote:
> > Hello Wei,
> > It would be great if you could give your thoughts on this. Looking
> > forward to hearing from you.
> > Thanks,
> > Pawan
> > On Tue, Apr 12, 2016 at 10:54 PM, Pawan Reddy Sibbala
> > <ps849 at cornell.edu <mailto:ps849 at cornell.edu>> wrote:
> > Hi Wei,
> > I have a question about ethernet support on the rocket FPGA
> > implementation ( tethered and untethered versions ).
> > In the tethered version, it is mentioned that HTIF is used to
> > service system calls for peripheral device emulation. Can rocket
> > core on the FPGA send packets over the ethernet? I don't think it
> > has support for it but I'm trying to get a sense of what needs to
> > changed/added to make this support? Could you give your thoughts
> > on how one can do this?
> > It seems like the untethered version has support for UART and SD
> > card. How different would it be to add ethernet support for this
> > when compared to the tethered version with HTIF?
> > Thanks,
> > Pawan
> > --
> > Pawan Reddy Sibbala
> > M.Eng ECE
> > Cornell University
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