arria v GT FPGA development

Hello, everyone

I am using a arria v GT FPGA development board, The development board have two Arria V GT 5AGTFD7K3F40I3N FPGA. I need communication between the two FPGA. I see they have inner LVDS ligature in the schematic diagram, but I can't find the pin name in the "development board reference manual". So I don't know how to communicate between the two FPGA. So I need help. Thank you, Best Wishes.