Adding a custom component

If you want a counter enable signal for a counter external to your sopc, you can simply use a PIO. Then you connect the counter output to LEDs and control the PIO-output/enable from Nios or whatever you have inside the sopc.

If you want to completely integrate into sopc builder, you must create a new sopc custom component from any counter hdl code: you must add an Avalon slave interface on one side in order to control the counter and conduits on the other side for count output.