SerDES with FPGA Rocket I/O, Aurora at 40 Gbits/sec???

Question

Hi,I am currently using the Virtex-II Pro FPGA FF672 evaluation board fromXilinx. I have implemented the Aurora protocol and used that to send mymodulated spectrum through the MGTs onto a spectrum analyzer.Now I have got a weird task:There's a Virtex-II Pro FPGA that receives data from 4 MGTs at10Gbits/sec. Is it possible to combine the data and send it out at 40Gbits/sec on the Rocket I/O??I can only think of a multiplexer that selects one of the 10Gbits/secand send it out on the Rocket I/O (the speed would be the same). 40Gbits/sec--> I have no idea.Do let me know if you have come across such a problem and are aware ofany solutions/pointers??Thanks,Vivek

Peter Alfke · Accepted Answer

Vivek, the present state-of-the-art in CMOS-FPGAs is that:

3.125 Gbps is fairly easy with dedicated transceivers (unidirectional, differential) 6 Gbps is doable in the same way 10 Gbps is very demanding, but has been proven to be possible, anything faster is impossible for a few years to come.

The world of dedicated chips us> Hi,

Vivek Menon · Answer

Thanks for the pointer, Peter.But is there any way of combining say 4 X 2.5 Gbit/sec Rocket I/Os andsend a 10 Gbits/sec on another Rocket I/O. Even the proof of conceptwill suffice.Thanks,VivekPeter Alfke wrote:

Sean Durkin · Answer

There are Virtex-II Pro X parts that have 10Gbit/s-capable RocketIOs, so with those it should be possible to have 4x2,5 Gbit/s coming in on 4 RocketIOs and send out 10gbit/s through another RocketIO. But the Pro X parts are hard to come by.

cu, Sean

Vivek Menon · Answer

Hi Sean,Can you please elaborate on Virtex-II Pro X and the technique tocombine 4x2.5 Gbit/sec into 10 Gbit/sec?Thanks,VivekSean Durk

Falk Brunner · Answer

Vivek Menon schrieb:Very simple. The key word is channel bonding. This is done every day in the 10G XAUI interfaces. So the idea is not new and it is doable without too much trouble.RegardsFalkP.S. The 4x2.5G is 4x3.125G due to 8B10B coding.

Peter Alfke · Answer

Yes, we support "channel bonding", which means we can use fourtransceivers, each at 2.5/3.125 Gbps to operate with a throughput of 10Gbps. But it involve four transceivers and four physical connections.I think Vivek's question was whether the four channels can be combinedto one.Physical the answer is "NO". Virtual the answer is "YES", throughchannel bonding.Peter Alfke==========Falk Brunner wrote:

Vivek Menon · Answer

Hello,After reading up the Aurora user guide and the different replies forthis topic, I have a couple of questions:Assume I have two V2 Pro or V4 boards with 8 Rocket I/O outputs each. Ihave 4 Rocket I/Os (TX side=4 X 2.5 or 3.125 Gbits/sec) on Board 1connected to 4 Rocket I/Os (RX side=4 X 2.5 or 3.125 Gbits/sec) onBoard2. I have also implemented Aurora protocol. Now is it possible toenable channel bonding and take the output from the 5th Rocket I/O (TXside) on Board 2 and safely assume that it transmits 10 GB/sec.If what I have described holds true, the same concept can be used tocombine the data on 4 X 10 Gb/s(which cannot be achieved now).Also, if anyone has suggestions on what specific parameters are to bemodified in Aurora, please let me know. I think the three parametersthat need to be changed are:INST aurora_module_i_1/lane_0_mgt_i CHAN_BOND_MODE           = OFF;INST aurora_module_i_1/lane_0_mgt_i CHAN_BOND_ONE_SHOT       = FALSE;INST aurora_module_i_1/lane_0_mgt_i...

Falk Brunner · Answer

Vivek Menon schrieb:If the MGTs would support 10G.Since you dont have a 40G MGT. But you can do channel bonding using 16 MGTs @ 3.125 Gbit/s to form al logical 40G data channel.RegardsFalk

SerDES with FPGA Rocket I/O, Aurora at 40 Gbits/sec???

Join the Discussion

Didn't find your answer?