Virtex-4 RocketIO and G.709 OTU-2

Unfortunately, even OC-192 is excluded form Virtex- 4 (ug076.pdf : "Payload compatible only"), so no hope for OTU-2 I think. We have to wait Virtex-5 family ?

I don't know about this protocol exactly, but for 10GBit Ethernet, which is a similar speed, you can use interfaces like XAUI (4x3.125Gbit) - if there is either a standard interface or a chip that could do this for you, then V4 could still be a contender.

Jeremy

No. That is unlikely to have sufficient jitter performance, due to certain compromises that must be made when putting an MGT on an FPGA. In particular, it's likely to use a ring oscillator rather than an LC oscillator which would have better perfomance.

Use an external SERDES designed for G.707 / G.709 work.

Note that (before they discontinued it) Xilinx's standalone SERDES didn't meet the SONET jitter requirements either, so getting these things to work is clearly not a trivial task.

Regards, Allan

even if ... Does anyone really have those Virtex4 in that super-speedgrade -12X? To me it sounds like they won't be available anytime soon ... :-(

bye, Michael

Can you indicate me such a SERDES. It's perfect if its output is

Thnaks > >

Most 10Gb/s SERDES parts seem to have 16 bit interfaces, probably because there's common interface definition called SFI-4 that has 16 LVDS pairs clocked at 622-670MHz.

Xilinx has an app note called XAPP 622 that describes how to implement such an interface on an FPGA.

Did you use Google? You would have found SERDES manufacturers such as PMC, AMCC, Broadcom, etc.

Thanks for the top-post!

I have seen that note as well. Can someone explain what "Payload compatible only" means?

I have seen that note as well. Can someone explain what "Payload compatible only" means?

I have seen that note as well. Can someone explain what "Payload compatible only" means?

I have seen that note as well, but I don't understand it.

Can someone explain what "Payload compatible only" means?

Is jitter the only limitation? Most fiber optic transceivers (XFP & friends) have eye openers of their own and resynchronize everything anyway.

regards, Gerhard

The -11X speed grade is dead as of this week. Do this some other way.

An XFP will have a JTF bandwidth in the order of 1MHz. A SERDES will have a JTF bandwidth of 1-2 orders of magnitude less than that, so resynchronisation in the XFP doesn't solve all the jitter problems.

Regards, Allan