If the synthesis option "KEEP_HIERARCHY" is set to "YES" the MIG 7 Series designs will fail during the MAP stage with an error similar to the following:
ERROR:MapLib:1121 - u_mig_7series_v1_5/u_memc_ui_top_std/mem_intfc0/ddr_phy_top0/u_ddr_mc_phy_wra pper/gen_dqs_iobuf_default.gen_dqs_iobuf.gen_dqs_diff.u_iobuf_dqs/OBUFTDS is driven by u_mig_7series_v1_5/u_memc_ui_top_std/mem_intfc0/ddr_phy_top0/u_ddr_mc_phy_wra pper/u_ddr_mc_phy/ddr_phy_4lanes_0.ddr_phy_4lanes/ddr_byte_lane_B.ddr_byte_la ne_B/ddr_byte_group_io/dqs_gen.oddr_dqs (Q pin) and u_mig_7series_v1_5/u_memc_ui_top_std/mem_intfc0/ddr_phy_top0/u_ddr_mc_phy_wra pper/u_ddr_mc_phy/ddr_phy_4lanes_0.ddr_phy_4lanes/ddr_byte_lane_B.ddr_byte_la ne_B/ddr_byte_group_io/dqs_gen.oddr_dqsts (Q pin), but they are not all in the same level of hierarchy. Please ensure that any OBUF(T)DS with differential IOSTANDARD that is driven by a register or OSERDES exists in the same level of hierarchy as its drivers. This may be achieved by setting KEEP_HIERARCHY=FALSE on those levels of hierarchy separating the OBUF(T)DS from its drivers.
Setting "KEEP_HIERARCHY" to "YES" is not supported for MIG 7 Series designs.
To work around the issue, KEEP_HIERARCHY=NO can be set locally for the MIG design.
Here is some example syntax for setting the KEEP_HIERARCHY option locally in the RTL: