rx phase compensation fifo

Hi,

I had almost the same issue as you.

You can use a different clock at the output of the fifo, but it has to have exactly the same frequency (which is the case if you use the rx_clkout of gxb1 to feed gxb2).

And you have to tell quartus that both clock have the same frequency (GXB_0PPM_CORE_CLOCK property). I was trying for quite a time until I found the correct syntax.

Try this:

set_instance_assignment -name GXB_0PPM_CORE_CLOCK ON -from "fiber_trx_lev1_aria2gx:Fiber_Lev1_Left|rx_clkout[0]" -to {the serial input port of your top level design[0]}

set_instance_assignment -name GXB_0PPM_CORE_CLOCK ON -from "fiber_trx_lev1_aria2gx:Fiber_Lev1_Left|rx_clkout[0]" -to {the serial input port of your top level design[1]}

(maybe you need to adapt the command a bit)

The strange thing for me is that in the "-to" field you need to assign the serial input port which comes at a much higher rate. But I got it working this way.

See http://www.alteraforum.com/forum/showthread.php?t=21970 for my configuration.

Cheers.