how to use the loopback boards?

if you've installed the CIII development kit files the loopback schematic can be found at:

C:\altera\72\kits\cycloneIII_3c120_dev\board_design_files\schematic\loopback_hsmc\debug_header_breakout.pdf

match the signals with the HSMC connector on the board schematic at:

C:\altera\72\kits\cycloneIII_3c120_dev\board_design_files\schematic\c3_f780_host.pdf

then you can run signals out of the FPGA, through the loopback adapter, and back into the FPGA.

Thank you thepancake.

So the purpose of feeding the output of the fpga back to its input is for debugging? I'm trying to understand the idea behind doing it (basic questions: why would one do that). Maybe I can make use of it. Any books or references as examples? I tried looking for materials but maybe I'm not using the right keywords.