I have a SMT338 board. This is a FPGA module and now I want to add a DDR SDRAM to my system. I have the ucf file provided by the company but in this file I don't find ddr_feedback clock. What it means?. I suppose that this pin is neccesary, but there is no pin called "feedback" or "clk_fb" or "clk_ddr". I only see the clock signal "ck" y "ckn" but these signals are used by the fpga to the ddr.
Has anyone the solution?.
Regards