lwIP RAW mode support for V4 temac

I use sockets.

Cheers, Jon

At X-Fest they said that raw mode will be available with EDK9.2, which is supposed to be available sometime after ISE9.2, which is scheduled for September, IIRC.

--
My email address is only valid until the end of the month.
Try figuring out what the address is going to be after that...

Thanks for the info. Unfortunately September is a little too late in my case...

Patrick

Why do you need a RAW mode? Do you actually need a TCP/IP stack? If not you can write directly to TEMAC and send RAW frames at highest speed possible.

Guru

If you browse to my website at

I have posted the source to a LWIP driver and startup code for a raw API TCP client application that runs on the V4fx ML403 board on top of Xilkernel (though it could be just as easily standalone at present.)

LWIP using sockets was far too slow for us, so I put this together using the Temac sockets code for EDK 8.2/9.1 and the emac raw api driver (I think for an older EDK version). So far this is tested only for receiving TCPIP packets, which it does at

3-400 Mbps, which is in line with Ron Wright's presentation at Xfest recently. Using a good 32 bit memory aligned memcpy function instead of the many bytewise packet copies in LWIP should be an easy first step to improve this rate.

You are welcome to use this as a starting point, but be aware that I am a novice at LWIP, TCP/IP internals and Xilinx, and the output routines are totally untried or tested, except for those used by the lower levels (ARP and ACKs etc.). More info in the ReadMe file on site.

Paul

Ave Paul! There is a lack of fast and free TCP/IP stacks which work with TEMAC. It would be nice to port your stack to GSRD design

gsrd) to get a maximum speed and royalty free reference design. I got this design working on Avnet Virtex-4FX12 MiniModule, which is a low cost high performance OEM module. Unfortunatelly there are no good reference designs which can exploit this performance. If I were a better SW engineer I could help you on development from which both would benefit.

Guru

Well, we need to send data using the TCP protocol ideally, but the UDP protocol could work as well. So my understanding is that a TCP/IP stack is required in our case. Maybe we could construct our own UDP packets without a stack though...

RAW mode is simply to acheive better performance than sockets mode and also to ease the development (we don't want to bother with an OS and threads).

Thanks.

Patrick

Thanks a lot Paul. Your XTemacif.c driver is exactly what is needed (which should have been provided by Xilinx in the first place). I didn't feel like I had the knowledge to write it myself, thanks for sharing your code!

Patrick

Hi Guru,

I am the hardware engineer who is working with Paul. I'd love to hear any comments you might have on our approach.

Our application specific IP that must also fit in the FPGA is a PLB master DMA device that uses about 50% of the BRAM and 25% of the fabric in the FX12. We originally were going to use the FX12 Minimodule, but switched to the ML403 to get 2x the DDR bandwidth. We can get by with

400 Mb/s performance for now, but would like to get 800 Mb.

It seemed like all the GSRD examples almost filled a FX12, particularly with BRAM usage, so we used the EDK supplied PLB TEMAC core and the PLB DDR controller for now.

Since our app only needs high speed in the receive direction, it seemed like it should be possible to remove half the GSRD logic (i.e. the transmit part) and then everything would fit. As someone who has worked with the GSRD, do you have a feel for how hard this would be? Or would you guess the full GSRD (both directions) could fit with our IP somehow? The critical resource seems to be BRAM and it always seemed like the xilinx IP really used more BRAM that it should.

thanks, Jeff

Jeff,

My GSRD design uses about 70% of FX12 logic resources and about 60% of BRAMs. BRAM usage is easy to control since you can set FIFO size from

1BRAM for a MPMC2 port. The best of MPMC2 is an NPI port which simplifies the user peripherals with DMA - what I use for image acquisition. I also tested TEMAC transfer rates to the PC: 730Mbit 1.5k MTU and 850Mbit for 7k MTU. If you need any additional resources do not hesiste to contact me.

Guru

Hi, I'm trying to transfer a small .bin file of size utmost 1-2MB from PC to sdr ddrram of ML403 using a crossover Ethernet cable (TCP/IP). I'm using PowerPC and plb bus. How do I write a socket program to transfer the file?