AR# 10644: 3.3i Foundation ISE Project Importer - I/O macros are not recognized by FPGA Express.
3.3i Foundation ISE Project Importer - I/O macros are not recognized by FPGA Express.
Keywords: ISE, Project Navigator, Importer
General Description: On designs imported from the Foundation schematic to ISE, Synopsys is inserting IBUFs in front of IFD symbols for Virtex-derived families. This is causing the implementation tools to error out.
This does not appear to happen for 4K families.
Solution 1: In Foundation Schematic, change the IFD to an FD, and add an IBUF on the data input to the FD. Then, set the "Pack I/O Registers/Latches Into IOBs" option to "For Inputs And Outputs" under the Map - Properties of ISE.
Solution 2: "Insert I/O Buffers" must be de-selected in FPGA Express, and all IBUFs and OBUFs must be instantiated.