interface stratixIV with an external ultrafast comparator

I think that making use of the latch function of the comparator is the only way to make it work. By connecting the latch input to a GT output generating a 5GHz clock the output timing of the comparator is now synchronous to the reference clock of the GT receiver. The GT receiver will have to be kept into the LTR mode as the data signal has no clock information embedded. I suppose phase shifting the reference input clock of the GT receiver will be useful in aligning the data input.