> Very interesting idea. The obvious advantage of FireWire is guaranteed > bandwidth, which would be very nice, and I was not > aware that FW800 supports being run over CAT5e!
More importantly, they claim that Mar&Long> it can maintain 400 Mbps over 75 meters of cable and Mar&Long> 200 Mbps up to 100 meters. 1394a is limited to only 5 meters, not even close to long enough. This is the reason I decided on Ethernet rather than 1394 in the first place. 1394b's 75 meters would be acceptable. We will need to confirm this, but it sounds promising. A 1394b solution might be less expensive than an Ethernet solution. > The only problem I see is that we won't support ethernet, something > that a lot of people will want. I assume you can't run both Ethernet and 1394b over the same cable at the same time. So if you need both, you'd need to run yet another cable through the walls. And most computers have Ethernet these days, while 1394a is rare and 1394b is very rare. > Solution: Have both FW800 and GBE on the board. A more flexible solution, although it may increase the cost. It doesn't have to be gigabit, 100 Mbps is enough. (e.g. if a chip already has 100 Mbps we don't need to add gigabit) > People who care will use FireWire, and normal > customers who don't mind the occasional interruption > due to packet loss can use GBE ;-) TCP with some buffer memory works fine. > We should actually be able to integrate some sort of switch to have > them come out of the same CAT5e/RJ-45 port. What would be the advantage of doing this? > Since there has not been any consensus about what chips we are going to > use We have several candidates but very little info on them. I'm beginning to fear that the decoder chips have the same problem as the GPU chips, no documentation available. > I chose the "TI DSP + FPGA" model. Did I miss a "TI DSP + FPGA" discussion? I assume the idea is to use a small FPGA to magically offload enough that the TI DSP can then do what we need? > (though right now it looks as if Spartan-3/DSP, > Cyclone III, or XP2 is the right family level for FPGAs, Cost? Power consumption? > TMS640C6412 DSP since it is 4000-4800 MACs for $40), Is this faster or slower than TMS320DM6446 ? ----------- Mar&Long> IP-based networks must be configured in a star topology. This is incorrect. Mar&Long> Mechanisms are built into the protocol to maintain the Mar&Long> isochronous streams during a bus reset. This prevents Mar&Long> disruptions to the audio or video as new devices are Mar&Long> attached or removed from the network. Is this new for 1394b ? Bus resets are very disruptive on 1394a. _______________________________________________ Open-hardware-ethervideo mailing list [email protected] http://lists.duskglow.com/mailman/listinfo/open-hardware-ethervideo
