fan-in & fan-out

Fan-in refers to input signals that feed the input equations of a logic cell.

Fan-out refers to output signals that are fed by the output equations of a logic cell.

Fan-In and Fan-Out statistics vary in different sections of the Quartus^® II software. Fan-Out in the Global & Other Fast Signals section of the Compilation Report lists the number of different cells and pins that the pin feeds. Fan-In and Fan-Out in the Routing Statistics in the Properties dialog box lists the number of different routing paths fed by the pin - some of which may feed multiple cells. The Equations window Fan-In and Fan-Out list the number of different equations fed by the pin, some of which may be in the same cell and have the same routing.