Verilog HDL Example Instantiation

//myddio_bidir is an instance of the altddio_bidir megafunction

        myddio_bidir sample_ddio (     .aset(aset),

                                       .combout(combout),

                                       .datain_h (datain_h),

                                       .datain_l(datain_l),

                                       .inclock(inclock),

                                       .oe(oe),

                                       .outclock(outclock),

                                       .padio(tmp_padio),

                                       .oe_out(tmp_oe),

                                       .sclr(sclr)

                                 );

alt_bidir_buf my_bidir (.bidirin (tmp_padio), .oe (tmp_oe), .io (bidir)); //Here, ”r;bidir” should be declared as an inout port.
Important: To successfully perform RTL simulation and formal verification, use lowercase primitive name in instantiation.