Stratix IV GX dev kit

[Altera_Forum]

Hi all, 

 I am looking at buying the Stratix IV dev kit. It comes with 8 transceivers routed to SMA connectors, but I need 16. Is it feasible to (with a decent performance) synchronize two of this boards by using the clock input/output?  Any other thoughts on what to use to get this 16 transmitters working?  Thanks in advance!

[Altera_Forum]

--- Quote Start ---   I am looking at buying the Stratix IV dev kit. It comes with 8 transceivers routed to SMA connectors, but I need 16. Is it feasible to (with a decent performance) synchronize two of this boards by using the clock input/output?  Any other thoughts on what to use to get this 16 transmitters working?   --- Quote End ---    You mean the Stratix IV SI kit?  You can also use the Stratix IV GX development kit. It has two HSMC connectors with 8 + 6 transceivers, and then the PCIe edge connector with another 8 transceivers. Samtec sells cables for HSMC-to-SMA breakout and for PCIe-to-SMA breakout.  The DE4 kit could also be used.  Cheers, Dave

[Altera_Forum]

Thanks for your quick answer Dave! 

 Regarding Stratix IV GX dev kit, problem is that the reference manual quotes 12 channels with 8.5 Gbps + 6 with 3.5 Gpbs (I don't know why). That is in page 2-5. I would like all of them to have the same performance. I am also not sure about the PCI: can I just use that physical interface but custom configure the transceivers?  The DE4 is a little bit of the same: it quotes only 12 transceivers available.  http://www.terasic.com.tw/cgi-bin/page/archive.pl?language=english&categoryno=138&no=501&partno=2  So I still don't know what to do. Am I reading any of this availability in a wrong way?

[Altera_Forum]

can you give more information about what you're trying to do? not only are there physical restrictions on how many transceivers are accessible through HSMC or SMA, but there are clocking resources and other place and route issues to consider. these sorts of questions can only be answered by doing a feasibility study in the Quartus

[Altera_Forum]

and though its still early and ES, have you looked at the SV SI kit?

[Altera_Forum]

--- Quote Start ---   Regarding Stratix IV GX dev kit, problem is that the reference manual quotes 12 channels with 8.5 Gbps + 6 with 3.5 Gpbs (I don't know why).    --- Quote End ---  Let me look at the schematic ... p8 has the transceiver connections on the FPGA. The transceivers are all connected to true transceiver channels, not the 6.5Gbps CMU channels, so they are all capable of 8.5Gbps. Its possible that they don't want to 'quote' that due to the layout. I've been using the HSMC connections at 5Gbps without issues.    --- Quote Start ---   I am also not sure about the PCI: can I just use that physical interface but custom configure the transceivers?   --- Quote End ---  Yep, you can configure it to do what you like. The only caveat is that the transmitters have AC-coupling caps on them. If you needed a DC connection, you could replace them easily enough.    --- Quote Start ---   The DE4 is a little bit of the same: it quotes only 12 transceivers available.   --- Quote End ---  I don't have one of these, so you'd just have to look at the schematic and see what they've routed. Chances are they are not quoting the PCIe interface transceivers in that list, since they assume you'll want to use the board in a PCIe slot. However, both boards work fine standalone on the bench.  Cheers, Dave

[Altera_Forum]

"can you give more information about what you're trying to do?" 

 what I want to do is to have 16 high speed transmitters that I am going to use just as high speed serializers with around 5 Gbps max rate (protocol in Basic mode, all the blocks bypassed, only a high speed serializer per channel going on). The only requirement is that I need all of them to be synchronized (and that I might need long chains of 1's or 0's, so it will be DC coupled, but that should not have anything to do with this).  "and though its still early and ES, have you looked at the SV SI kit? "  yes, but again it does not have 16 channels routed through the same interface, which would be preferable. However, based on what you are saying, I might have to deal with that anyway.  Ok, so regarding the stratix IV (or even de DE4), suggestion would be to use the HSMC with maybe the samtec arrangement to sma, and the PCI to sma too. All that would allow to have all channels with the same performance and synchronized? What I don't like as I said is the complexity of having two or three different adapter boards - connector interfaces - etc, but it looks like the only way to get 16 channels to work.  Any thoughts about synchronization of 2 Stratix IV GX with the 8 SMA transceivers?  Thanks a lot!

[Altera_Forum]

--- Quote Start ---  "can you give more information about what you're trying to do?"  what I want to do is to have 16 high speed transmitters that I am going to use just as high speed serializers with around 5 Gbps max rate (protocol in Basic mode, all the blocks bypassed, only a high speed serializer per channel going on). The only requirement is that I need all of them to be synchronized   --- Quote End ---    Synchronous, or synchronized?  The channels will all be synchronous, because you can use a common reference clock. However, there is no guarantee the serial data streams from transmitters are time-aligned (synchronized).  What exactly are you trying to do?  Cheers, Dave

[Altera_Forum]

--- Quote Start ---   Any thoughts about synchronization of 2 Stratix IV GX with the 8 SMA transceivers?   --- Quote End ---    I use the clkout_sma on one board to send its reference clock to a second board. The transmitters on one board route to receivers on the second board. The receivers start off in lock-to-reference mode, and then switch over to lock-to-data mode to capture the data from the transmitters.  You need to ensure that the transmitter data stream has enough toggles so that the lock-to-data logic at the receivers work. You can use a PRBS sequence at the transmitter to modulate data, and then a PRBS sequence at the receiver to demodulate. When you power-up, you first have to synchronize the PRBS generators between boards, and then enable transmitter data.  Cheers, Dave

[Altera_Forum]

Dave, 

 I just want to use the 16 channels as serializers: output 16 parallel arbitrary sequences of bits that will be stored in memory in the FPGA. There will be no receiver, and there is no protocol involved. It is just a serializer. This will be used to test a piece of equipment that I have.   The reason to use transceivers is that I need to have the ability of precisely align the edges of the 16 channels (in the subnanosecond range), and for that I need the very high frequency clock that the transceivers provide. Those edges have also to be sinchronized between them (if two transitions should happen at the same time, they cannot happen 1 ns apart). I understand that there is no output feedback / pll that guarantees that they will be synchronized, but hopefully there will be minimal variation between channels if they are all locked to the same clock (I hope in the low picosecond range). That obviously depends on how the internal hardware design, but I would expect them to be almost identical.  Does that make sense?  I am sorry if I am not been able to clearly explain what I want to do; it is really very simple but I find it hard to write it down.  Thanks,  Miguel

[Altera_Forum]

--- Quote Start ---   Does that make sense?   --- Quote End ---    If you want the same sequence on all 16 channels, then you might be better off using an RF splitter.  If you want different sequences on all 16 channels, then you will have to use multiple transmitter channels.  You should be able to enable data synchronously across channels, and if you can't, if you can tell they are misaligned, you can always insert a bit-slip component that shifts the serial stream 1-bit at a time.  Cheers, Dave

[Altera_Forum]

i didn't see that the SV SI kit 21 channels of backplane transceivers weren't sent to the same connector 

 have you looked at the non-transceiver output delay chains? they are adjustable in 50ps increments

[Altera_Forum]

Pankake, 

 the output delay adjustment cannot be used for this, I have checked that. Thanks for the suggestion anyway.  Dave,  it's all different sequences, so I do need the different channels. I have checked the Samtec interfaces and it does not seem obvious to get that up and running quickly. This should be a quick-development initial prototype, so I think I will buy one Stratix IV GX with the 8 transceivers to SMA and figure out if that can do what I want. After that I will bug you again with the synchronization :)  Thanks a lot for your help, both of you!

[Altera_Forum]

--- Quote Start ---   it's all different sequences, so I do need the different channels.   --- Quote End ---    Ok.    --- Quote Start ---   I have checked the Samtec interfaces and it does not seem obvious to get that up and running quickly. This should be a quick-development initial prototype, so I think I will buy one Stratix IV GX with the 8 transceivers to SMA and figure out if that can do what I want. After that I will bug you again with the synchronization :)   --- Quote End ---    The Samtec interfaces are just breakout cables. You just plug them in :)  Cheers, Dave

[Altera_Forum]

"The Samtec interfaces are just breakout cables. You just plug them in " 

 You are right Dave :), I am being lazy here. It just does not seem very straightforward to buy them. I have asked them for a quote already.  The information on the dev boards is sometimes confusing, so here it goes in case it helps someone and someone can help me. The Stratix IV SI kit with 8 SMA channels actually has the 8 channels routed through different paths, to provide insight on the effect of different transmision paths on the SI. So the channels are not matched. That is not very difficult to fix but I think it is annoying.  Here is different option based on the Stratix IV TR4 dev board  http://www.terasic.com.tw/cgi-bin/page/archive.pl?language=english&categoryno=138&no=683&partno=4  in the reference manual there are 8 channels routed to HSMC-A and 8 routed to HSMC-E. That, plus the adapter XTC-HSMC (or a similar, custom one that provides the right amount of channels) can do it. But once again something confusing: in the webpage they list only 8 transceivers available.  If any of you has any experience with this board I would appreciate any comments. I will directly ask Terasic about this. Otherwise I hope this is the right choice.  Again thank you all for your help!  Miguel