Does the Spartan-6 LX family or Spartan3A support
the Multipoint-LVDS
specifications?

We need input and ouput buffers compliant to M-LVDS type1 and types
2.

Also , the buffers should be 5V LVTTL tolerant.

a,

If it is not in the data sheet, then it isn't supported.

I have no idea what "multi-point" LVDS is:  sounds like someone's idea
of how to ruin a perfectly good point to point IEEE standard!

OK, I just read about it on Wikipedia, and that confirms my
suspicions ...

There is the "bus-LVDS" which we 'invented' and supported, but the
signal integrity of that is a compromise at best, and I have never
really liked to deal with it at all.  Regardless, it does work (within
its limits).

For 5v tolerance, I suggest level shifters, or using resistors.  At
these advanced technology nodes we are lucky to be able to still use
3.3v IO!

Austin

> Also , the buffers should be 5V LVTTL
tolerant.

Which?  5V, or LVTTL?  They are two different things.

IIRC, Spartan-6 does support LVTTL.  It does not support 5V I/O
directly.