07-15-2011 02:54 AM
Can the 'hard' TEMAC in the Virtex-5 FXT be persuaded to operate at the 2.5Gbit not-quite-standard Ethernet rate?
07-15-2011 07:17 AM
This block wasn't designed to support this. it "may" be possible but I haven't seen it done personally and appears to violate the documented datasheet specs.
A few other notes:
-From what I understad, 2.5Gbps Ethernet (1000-Base X only) isn't an official IEEE spec but is supported by a number of IC vendors
-I have heard of at least one user getting 2.5Gbps Ethernet to work on Virtex-5 using our soft core
-The Virtex-6 hard TEMAC does support this
I don't know if that helps. it definitely isn't a hard yes or no but though you might appreciate the datapoints more than a "no." I'm not sure I would feel comfortable doing this on my own design even if it appeared to work on a limited sampling.
2.5Gbps operation likely isn't supported either with the soft TEMAC but is arguably a different situation because of implementation differences, timing analysis, etc.
07-16-2011 11:55 AM
If you look at Table 49 in the Virtex-5 data sheet, DS202, you will see specifications for opeating at 2000 Mb/s which is a line rate of 2.5 Gbps after the 8b/10b encoding.
07-18-2011 01:20 AM
07-18-2011 01:21 AM