Honored Contributor
Honored ContributorDoes anybody know if there are any parts out there that can still do CDR at 200 Mbps?
I believe Stratix II GX and Arria GX require at least 640 Mbps for CDR. Stratix III offers a new "soft clock-data recovery" for the LVDS channels. You might be able to do that if you can interface with LVDS. I'm not sure what the restrictions are. 1 - At such slow speeds, you would normally oversample and extract the data. So you could bring the data into a Stratix II GX, Arria GX, or Stratix IV GX transceiver and sample at say 2Gbps. 2 - You've indicated you're using your own encoding so you're probably using your own protocol. The only IP I can think of that would be useful to you would be the GXB megacores and the Triple Speed Ethernet MAC. Your data throughput is high enough that you'll likely have to do all of the UDP/IP protocol in firmware. Regarding oversampling. You have to write the code to due the data extraction and alignment. This isn't so bad. You basically look for bit transitions to determine the sampling midpoint. Then you pass the oversampled data to a phase alignment block which looks for a specific bit pattern and presents the over-sampled phase aligned data for processing. 3 - 200 Mbps (100MHz) is relatively slow so I don't think you'll have trouble having a board that can handle that. The only board I can think of off hand with any optical connectors is the Stratix II GX Audio / Video development kit and it certainly doesn't have 5 optical inputs. If you're going to use GX transceivers then you'll need a board that brings 5 of the transceiver inputs out to connectors. I don't think there is a board that will exactly meet your needs but your best shots are probably: http://www.altera.com/products/devkits/altera/kit-dsp-professional.html and http://www.altera.com/products/devkits/altera/kit-signal_integrity_s2gx.html Good luck, Jake
