Folks
Well now we are at
the point of our Saturday discussion. How fast? How Clean, How Many? None of
us knew, and we still don?t. Cecil did know and all of you have pointed to the
solution - lvds. The buss stuff really all started to unravel when Phil_C said
he needed an FPGA on the Radio board due to the probable lack of capability of
the buss to carry the A/D and other high speed sigs to and from the Lionheart.
Bill ? KD5TFD and I sort of said the same thing Saturday: ?If we can?t
leverage the Lionheart for all buss mounted FPGA projects now and in the
future, what is the point of the buss?? It would be nice to see any pin pair
be able to pass any frequency quietly. If it?s not possible then it?s not
possible. Also according to Cecil, an FPGA interfaced to an FPGA can do lvds
without any additional components but we still need twisted pair, or
coax.
Cecil suggested a
.100 pin header to which we would attach a twisted pair to a single pair
block going from board to board. It is a good idea for a couple of pairs of
pins, but if we need 16 pair or probably more, it is a little impractical, but
do-able.
I made a couple of
suggestions for mass termination or even a ?flexible buss? using twisted pair
IDC cable which didn?t garner any comments. This stuff does have flats and
twists so also may be impractical.