Hi All!
May be it's easy just modify Ettus code for support Tri-Mode Ethernet. I
think that it is not so difficult.
In that way we can chose Ethernet PHY work mode from host.
Also 'wait' feature (PAUSE frames / flow control) available not only for
Gigabit Ethernet. Some 10/100 Ethernet Controllers support it (for example,
LAN9218).
Regards,
Andrew Karpenkov
2012/7/27 Robin Coxe <coxe(a)close-haul.com>
Hi Sylvain.
On Fri, Jul 27, 2012 at 9:04 AM, Sylvain Munaut <246tnt(a)gmail.com> wrote:
Hi,
The Ettus UHD framework adopted for the umTRX
only supports GigE
(simple_gemac). A reworked, Wishbone-compliant 10/100 Ethernet MAC
is included in the OpenRISC SoC project on Opencores. It has been
ported to the Digilent Atlys board, which has a Spartan-6 FPGA.
http://www.chokladfabriken.org/projects/orpsoc-atlys
I'll begin the port of this Ethernet MAC (a cleaned-up version of the
10/100 core on OpenCores) to the UmTRX and test it on Close-Haul's
SP-605 Spartan-6 eval. board. I'm not quite sure how long this task
will take, but this feature falls into the
"nice-to-have-but-not-urgent" category.
But would it be 10/100/1000 ? or just 10/100 ?
Just 10/100. User would choose GigE or 10/100 via an IFDEF in the
Verilog. I suppose it would also be possible to multiplex in the
simple_gemac with this 10/100 core and set the mode from the ZPU via
the Wishbone interface. There is a tri-mode Ethernet MAC that Ettus
used to use on the USRP2, but I've never been able to make much sense
of it. If you have suggestions for a better way to add 10/100
support, I'm definitely interested in hearing them.
Also, doesn't UHD make use of the
'wait' feature of Gigabit (i.e.
PAUSE frames / flow control ) to avoid loosing data ? This doesn't
exist on 10/100 IIRC.
I'm not all that familiar with UHD, so you probably know better than I
do. Perhaps Thomas could comment?
-Robin
--
Robin Coxe | Close-Haul Communications, Inc. | Boston, MA
+1-617-470-8825