spartan-6 vs virtex-5

[buenos]

hi

i am planning a new project with xilinx FPGA and high speed ios, like x1-PCIe, x2-3G-serial-Aurora, 64bit-DDR3, 600MHz-LVDS, 133MHz DSP-bus.
Im not shure which FPGA family to use.
The question is, that is there any detail which makes a vitex-5 to be better than a spartan-6? for example io clocking arrangements, number of PLLs, diff clock networks, or anything else? sp6 seems to be a lot cheaper, and also seems to have a lot more flip-flops.

 

[farhada]

It all depends on how big your design is. SP6 is very good for high speed communication and special needs.

I am not sure what you mean by SP6 seems to have more FF, it all depends on what device you are using. The largest SP6 has definitely much more FF than the smallest V5.

 

[buenos]

in the product selection table, for a 20k logic cell devices of V5 or Sp6, the SP6 has more FFs. im not shure how they mean "logic cell".
for example compare sp6-45k device with a v5-30k device, in the aspect of logic resources, number of local io clock networks, etc.
my application would be some io bridge for host-pcie, an on-board dsp, an ADC with lvds interface and a common DDR3 frame buffer.

 

[farhada]

If you do not need the extreme resources available on V6 then Spartan 3A or Spartan 6 should be enough for your normal use.
DDR3 can be the only problem, I am sure you can connect DDR3 to SP6 but I don't think SP3A supports it.

The price different is huge, so if I was you, I would create my design, compile and synthesize it for different architectures and sizes and then make a decision based on that.

 

[buenos]

ok. probably i will do that.