Using ethernet on a Xilnx board (Help appreciated)

First of all let me apologize for any thing of things I"m ignorant
about here. Up until very recenty my programming experience was
limited to higher level programming language: Python, PHP, Perl, hell
at this point I'd consider C high level.

Anyway.

I'm trying to use a Xilinx XUPV2P board to send data over ethernet.
The board uses the intel LXT972alc to control the PHY and provide a
MII interface.

What I attempted to do was to build a valid packet, assert enable on
the pin labeled TX_ENABLE and feed that packet nibble by nibble to the
intel chip.

The packet itself is UDP datagram using IP. I put in the preamble,
ethernet header, IP header, UDP header, data and checksum. I used the
Ethernet broadcast address.

To try to test his out I thought I would plug my computer and the
board into a router. I have a C program that I wrote which picks up
and prints UDP packets sent to the appropriate port. I put the IP
address of my computer as when plugged into the router and tried to
send the packets there. However, no data seems to be getting through.
Furthermore, the absence of link up lights on both the router and the
board seem to indicate that the bord is not able to link to the
router.

For reference I programmed this in Verilog (which I learned about 2
weeks ago).

If anyone could provide me with advice I would much appreciate.

Thanks,
---AchatesAVC

"AchatesAVC" <AchatesAVC@gmail.com> wrote in message 
news:93a5add5-3221-49e4-83d1-b27cee18a6d2@59g2000hsb.googlegroups.com...
> Furthermore, the absence of link up lights on both the router and the
> board seem to indicate that the bord is not able to link to the
> router.

If it turns out that the Ethernet components are not working, I will 
consider buying the board from you (assuming nothing else is broken).

>
> For reference I programmed this in Verilog (which I learned about 2
> weeks ago).

The V2P has 2 onboard PPC405. Have you tried using an embedded core? Network 
stacks are not trivial components.

> Furthermore, the absence of link up lights on both the router and the
> board seem to indicate that the bord is not able to link to the
> router.

	You should have said so first.

	I don't know about the PHY you use, but usually after reset, an Ethernet  
PHY needs to be talked to softly using the MII protocol, which you then  
use to setup autonegociation, bring the link up, after which the LED will  
light on your router and you will be able to query the PHY to discover the  
actual link capabilities (duplex, speed, etc) and send and receive data.  
The PHY will also raise interrupts, which you should process, when the  
link state changes : disconnection, reconnection, etc.

	From what you say it seems you forgot to do this. In this case the PHY  
will simply stay in power down mode and frustrate you.

	You will need to have a look at the Linux kernel sources for an example,  
use the 2.4, the code is simpler than in 2.6, pick a NIC driver and grok.

	Ah, and yeah, you'll need somse sort of CPU to go through that  
initialization routine.

Thanks much for the replies.

Would it just make more sense to get an IP core for this if I need the
whole thing to be reliable?

-AchatesAVC

On Wed, 04 Jun 2008 21:43:39 +0200, AchatesAVC <AchatesAVC@gmail.com>  
wrote:

> Thanks much for the replies.
>
> Would it just make more sense to get an IP core for this if I need the
> whole thing to be reliable?
>
> -AchatesAVC

	Hm, well, if you want to do some more involved ethernet transfer  
(anything besides really basic stuff) yes you'll want an Ethernet MAC and  
some software to configure it and control it.
	If you just want to send raw data you can get away with configuring the  
PHY using the CPU and then sending pre-canned frames just like you've been  
doing.

	Xilinx has one in EDK, also one is on OpenCores.

	In my design I used a LAN9117 MAC+PHY chip from SMSC. I warmly recommend  
this chip to anyone, it is easy to use and will handle 100 Mbps full  
duplex without dropping packets. However you MUST NOT put it on a shared  
bus with, for instance, the RAM, because its bus is slow, and at full  
bandwidth it is busy a large percentage of the time. This is absolutely  
not a problem, unless it kills your memory bandwidth by the simple fact of  
sitting on the same bus !

	Also the CPU interface is very simple, it's really a no-nonsense chip  
(unlike the LAN91c111 which is a PITA).

	Of course it eats more IO than a PHY, but it eats less slices than a MAC  
in the FPGA...
	(and it works)

PFC wrote:
(snip)

>     I don't know about the PHY you use, but usually after reset, an 
> Ethernet  PHY needs to be talked to softly using the MII protocol, which 
> you then  use to setup autonegociation, bring the link up, after which 
(snip)

>     Ah, and yeah, you'll need somse sort of CPU to go through that  
> initialization routine.

Depending on the definition of CPU.  It could presumably be done
by a state machine which may or may not follow one's definition
of CPU.

-- glen

>>     Ah, and yeah, you'll need somse sort of CPU to go through that   
>> initialization routine.
>
> Depending on the definition of CPU.  It could presumably be done
> by a state machine which may or may not follow one's definition
> of CPU.
>
> -- glen
>

	Actually I use Microblaze, but I was thinking if he doesn't need a CPU he  
could use PicoBlaze, then I remembered he uses a chip with a PPC core...

On 2008-06-04, AchatesAVC <AchatesAVC@gmail.com> wrote:
> To try to test his out I thought I would plug my computer and the
> board into a router. I have a C program that I wrote which picks up
> and prints UDP packets sent to the appropriate port. I put the IP
> address of my computer as when plugged into the router and tried to
> send the packets there. However, no data seems to be getting through.
> Furthermore, the absence of link up lights on both the router and the
> board seem to indicate that the bord is not able to link to the
> router.

At a first guess this seems like the PHY is still in reset.
Doublecheck that you have setup the reset signal correctly in
your design. (UCF file and polarity respectively.)

If that seems ok you can try to talk to the PHY via the MII as
another poster suggested.

/Andreas

On Jun 4, 10:18 pm, PFC <li...@peufeu.com> wrote:
> >>     Ah, and yeah, you'll need somse sort of CPU to go through that
> >> initialization routine.
>
> > Depending on the definition of CPU.  It could presumably be done
> > by a state machine which may or may not follow one's definition
> > of CPU.
>
> > -- glen
>
>         Actually I use Microblaze, but I was thinking if he doesn't need a CPU he
> could use PicoBlaze, then I remembered he uses a chip with a PPC core...

Does anybody out here know where to find a ethernet MAC implementation
for Picoblaze? It would make a very lightweight eth. implementation,
which would suit my Spartan3E starter kit board perfectly. Microblaze
is a bit too resource-hungry for my project.

Bart

Hey,

Have a look at www.mvd-fpga.com they have IP cores which will allow you to 
use the ethernet interfaces very easilly.

Regards,

Pat

"AchatesAVC" <AchatesAVC@gmail.com> a &#4294967295;crit dans le message de 
news:93a5add5-3221-49e4-83d1-b27cee18a6d2@59g2000hsb.googlegroups.com...
> First of all let me apologize for any thing of things I"m ignorant
> about here. Up until very recenty my programming experience was
> limited to higher level programming language: Python, PHP, Perl, hell
> at this point I'd consider C high level.
>
> Anyway.
>
> I'm trying to use a Xilinx XUPV2P board to send data over ethernet.
> The board uses the intel LXT972alc to control the PHY and provide a
> MII interface.
>
> What I attempted to do was to build a valid packet, assert enable on
> the pin labeled TX_ENABLE and feed that packet nibble by nibble to the
> intel chip.
>
> The packet itself is UDP datagram using IP. I put in the preamble,
> ethernet header, IP header, UDP header, data and checksum. I used the
> Ethernet broadcast address.
>
> To try to test his out I thought I would plug my computer and the
> board into a router. I have a C program that I wrote which picks up
> and prints UDP packets sent to the appropriate port. I put the IP
> address of my computer as when plugged into the router and tried to
> send the packets there. However, no data seems to be getting through.
> Furthermore, the absence of link up lights on both the router and the
> board seem to indicate that the bord is not able to link to the
> router.
>
> For reference I programmed this in Verilog (which I learned about 2
> weeks ago).
>
> If anyone could provide me with advice I would much appreciate.
>
> Thanks,
> ---AchatesAVC