On an Altera device, a pin is a physical input, output, or bidirectional pin.
In Synopsys Design Constraints, a pin is an input or output of a cell.
In Block Editor files, a pin is represented by an INPUT, OUTPUT, or BIDIR symbol. In a Text Design File (.tdf), a pin is represented as an INPUT, OUTPUT, or BIDIR port. In a VHDL Design File (.vhd or .vhdl), a pin is represented as an IN, OUT, or INOUT port. In a Verilog Design File (.v or .verilog), a pin is represented as an input, output, or inout port. In a Waveform Vector File (.vwf), a pin is represented as a node with an input, output, or bidirectional I/O type and a pin input, registered, or combinational node type.
You can assign a logic function to a specific pin number. You can also assign a logic function to a row or a column to ensure that the function is implemented on a particular row or column and appears on a specified pin.