When using 9.1i SP3 and v3.5 of the Endpoint for PCI Express core, the following error might occur during MAP:
"ERROR:Place:543 - Due to placement constraints, the following 1 components cannot be placed. The relative offsets of the components are shown in brackets next to the component names.
ep/BU2/U0/interface_32bit.pcie_4_lane.pci_exp_4_lane_32b_ep0/plm/common/scr0/reg_tx_data_12_sn_N_3 (0, 0)"
This error is the result of the design being over mapped into a certain area. The error can be resolved by expanding the area constraint in the example UCF file.
INST "ep/BU2/U0/interface_32bit.pcie_4_lane.pci_exp_4_lane_32b_ep/plm/*" AREA_GROUP = "AG_EP_PLM" ;
AREA_GROUP "AG_EP_PLM" RANGE = SLICE_X84Y255:SLICE_X103Y150 ;
For example, expand the area group as follows:
AREA_GROUP "AG_EP_PLM" RANGE = SLICE_X84Y255:SLICE_X103Y100 ;
Notice that the Y coordinate was changed from 150 to 100.