求助：quartus II使用ddr3 IP核，综合时出错

kreil

quartus II使用ddr3 IP核，综合时出现这种错误，求大神指教，非常感谢：Error (15853): Input port IBAR of I/O input buffer "ddr3_inf2:ddr3_inf_data_q|ddr3_inf2_0002:ddr3_inf2_inst|ddr3_inf2_p0:p0|ddr3_inf2_p0_memphy:umemphy|ddr3_inf2_p0_new_io_pads:uio_pads|ddr3_inf2_p0_altdqdqs:dq_ddio[1].ubidir_dq_dqs|altdq_dqs2_acv_cyclonev:altdq_dqs2_inst|strobe_in" must be driven by a top-level pin
Error (15853): Input port IBAR of I/O input buffer "ddr3_inf2:ddr3_inf_data_q|ddr3_inf2_0002:ddr3_inf2_inst|ddr3_inf2_p0:p0|ddr3_inf2_p0_memphy:umemphy|ddr3_inf2_p0_new_io_pads:uio_pads|ddr3_inf2_p0_altdqdqs:dq_ddio[0].ubidir_dq_dqs|altdq_dqs2_acv_cyclonev:altdq_dqs2_inst|strobe_in" must be driven by a top-level pin
Error (15852): Output port "OBAR" of PSEUDO_DIFF_OUT primitive "ddr3_inf2:ddr3_inf_data_q|ddr3_inf2_0002:ddr3_inf2_inst|ddr3_inf2_p0:p0|ddr3_inf2_p0_memphy:umemphy|ddr3_inf2_p0_new_io_pads:uio_pads|ddr3_inf2_p0_altdqdqs:dq_ddio[1].ubidir_dq_dqs|altdq_dqs2_acv_cyclonev:altdq_dqs2_inst|pseudo_diffa_0" must drive only one OBUF primitive on the I port and cannot drive anything else
Error (15852): Output port "OBAR" of PSEUDO_DIFF_OUT primitive "ddr3_inf2:ddr3_inf_data_q|ddr3_inf2_0002:ddr3_inf2_inst|ddr3_inf2_p0:p0|ddr3_inf2_p0_memphy:umemphy|ddr3_inf2_p0_new_io_pads:uio_pads|ddr3_inf2_p0_altdqdqs:dq_ddio[0].ubidir_dq_dqs|altdq_dqs2_acv_cyclonev:altdq_dqs2_inst|pseudo_diffa_0" must drive only one OBUF primitive on the I port and cannot drive anything else