XVGA over UDP

I imagine you mean "UTP" which stands for Unshielded Twisted Pair such as CAT-5 cables. Two devices I was recently are:

and

which give RGB video over CAT-5.

If you actually want to use ethernet rather than a dedicated cable, your design goal may be too aggressive.

Or maybe UDP, User Datagram Protocol.

This sounds like a heap-o-work.

John

I have a very nice Ethernet-based daisychained KVM system for my Opteron cluster. (It's made by, gasp, IBM.)

There's a box that sits behind the power bar on the rack, which has 4 Ethernet ports, each of which can have 6 servers daisy-chained on it. Nice neat cabling, and it works over > 100 ft of cable if you want it to, and works up to 1600 x 1280 or perhaps higher.

Cheers,

Phil Hobbs

Are you sure it is Ethernet based?

To get 1600 x 1200 (probably not 1280) you need:

1600 x 1200 x 24 bits x 70 fps = 3,225,600,000 bits per second.

Yes, it could be compressed, and it could be less than 70 fps, but even so, you are talking about a lot of digital BW. Even gigabit might not be up to it for 1600 x 1200.

--Mac

as

your

Nice

UDP is the OP's input, he doesn't have to worry about data rates, he just has to display what's coming in. It's like a graphics card with an Ethernet bus instead of a PCI (Express) or whatever.

Put a processor + Ethernet driver in the FPGA to handle the UDP/IP stack, add an Ethernet chip and some memory for firmware and image buffer and use what's left of the FPGA to get the data on the display. Make it GCC compatible and most of the programming is done. See

for more info. Any cheaper won't be easy since most of it is already for free.

--DF

You don't have to transfer all of it as a single stream. Most frames will be identical. If you have a frame buffer at the receiver end, you'll just update part of framebuffer for which you have new data.

The sender can be as intelligent as you want it to be.

--
Reply to nico@nctdevpuntnl (punt=.)
Bedrijven en winkels vindt U op www.adresboekje.nl

What does UDP mean ? Does it mean there is an XWindow machine behind or does it just mean a pixel generator. The first is vector based and thus scalable and the second means dumb bitmaps. The first is part of each Linux distribution.

Rene

--
Ing.Buero R.Tschaggelar - http://www.ibrtses.com
& commercial newsgroups - http://www.talkto.net

Sure looks like it. I'm out sick today, but tomorrow I'll go look at the manual. Really a nice gizmo. I'm not at all sure it ships raw pixels at full bandwidth--which would be a putrid design choice for a (relatively expensive) cluster KVM thingummy--and of course it only has to ship the one it's actually displaying. There's a dongle for each server, which has either PS/2 or USB keyboard and mouse connectors, and a normal video connector. It also has an RJ45 plug and jack, for daisy-chain purposes, and an Ethernet terminator at the end of the string.

With some not-too-intelligent compression and a dedicated Gigabit Ethernet channel per chain, this is pretty doable, I think. I will have to check to see if there are resolution limits, but it certainly works at 1400x1050, because I use it that way all the time.

Cheers,

Phil Hobbs

The OP said UPD, not UDP. He may have meant UDP (as John Larkin suggested), and he may have meant UTP. Who knows?

In any event, the PCI bus can handle 33 MHz x 32 bit = 1,056,000,000 bits per second. Of course, there is overhead, so that is a bit optimistic.

Fast Ethernet is 100 megabits per second. Not even close. So it has to be gigabit Ethernet. But by today's standards, even gigabit isn't nearly fast enough for a video bus. In fact, it hasn't been for some time. Just try to find a high-end 32 bit 33MHz PCI video card.

I don't think you know what you are talking about. There would be no reason for a processor. Just an FPGA. And what do you mean by GCC compatible?

And why bother with all of this anyway? Just use X or remote desktop or whatever. Remote display over IP is a solved problem if the remote location is also a PC.

And if all you have is a keyboard, monitor, and mouse, there are long distance KVM deals which (AFAIK) send analog video over UTP.

On the other hand, I have often thought about designing a board which takes 480P in, digitizes it, and spits out UDP packets over gigabit ethernet.

This would allow you to send a movie from a DVD player over the LAN to any computer. I'm not aware of any design that does this. I guess to really be useful, you would have to put the audio stream in there, too.

Keeping up with the UDP packet rate might be a pretty big job for the receiving computer.

--Mac

Opteron

and

just

Ethernet

stack,

use

for

free.

I didn't notice the OP wrote UPD (he did write UDP in the subject) but supposing UDP he will need some kind of processing to get the IP stuff done. So put a processor IP in the FPGA for which a GCC cross compiler exist and use all the open source network stuff to get the job done. See what I mean? But if the OP means UPD I don't know what he is talking about.

Why bother is not my problem.

--DF

might

Probably UTP based. I've worked with KVM switches that used standard UTP cables but this had nothing to do with UDP or any form of digital communications. The UTP cables were simply used to transfer the analog video signal (RGB and sync) over 4 pairs in the UTP cables. So the maximum bandwith is then 1600 x 1200 x 70fps = 135MHz.

Meindert

Oops. You're right. So he probably did mean UDP.

Oh. UDP is simple enough so that you don't really need a full stack. I think an FPGA could handle it without resorting to a processor and full stack.

It's not just GCC. If you want to take advantage of open source network stuff, you need a fully supported platform with standard libraries, a kernel, and so on. And you need a boot loader of some sort.

Then you have to watch out that the licensing is compatible with your intended use.

True. You're not the OP! ;-)

regards, Mac