When I try to synthesize the PCI core I get some strange errors from ISE 7.1.04i (WEBPACK) **** start of error **** Analyzing module . ERROR:Xst:917 - Undeclared signal . ERROR:Xst:917 - Undeclared signal . ERROR:Xst:917 - Undeclared signal . ERROR:Xst:917 - Undeclared signal . ERROR:Xst:917 - Undeclared signal . ERROR:Xst:917 - Undeclared signal . ERROR:Xst:917 - Undeclared signal . ERROR:Xst:917 - Undeclared signal . ERROR:Xst:917 - Undeclared signal . ERROR:Xst:917 - Undeclared signal . ERROR:Xst:917 - Undeclared signal . ERROR:Xst:917 - Undeclared signal . ERROR:Xst:917 - Undeclared signal . ERROR:Xst:917 - Undeclared signal . ERROR:Xst:917 - Undeclared signal . ERROR:Xst:917 - Undeclared signal . ERROR:Xst:917 - Undeclared signal . ERROR:Xst:917 - Undeclared signal . ERROR:Xst:917 - Undeclared signal . ERROR:Xst:917 - Undeclared signal . ERROR:Xst:917 - Undeclared signal . ERROR:Xst:917 - Undeclared signal . ERROR:Xst:917 - Undeclared signal . ERROR:Xst:917 - Undeclared signal . ERROR:Xst:917 - Undeclared signal . ERROR:Xst:917 - Undeclared signal . ERROR:Xst:917 - Undeclared signal . ERROR:Xst:917 - Undeclared signal . ERROR:Xst:917 - Undeclared signal . ERROR:Xst:917 - Undeclared signal . ERROR:Xst:917 - Undeclared signal . ERROR:Xst:917 - Undeclared signal . ERROR:Xst:917 - Undeclared signal . ERROR:Xst:917 - Undeclared signal . ERROR:Xst:917 - Undeclared signal . ERROR:Xst:917 - Undeclared signal . pci_ba0_width = 20 pci_ba1_5_width = 24 Found 36 error(s). Aborting synthesis. --> Total memory usage is 88048 kilobytes Number of errors : 36 ( 0 filtered) Number of warnings : 2 ( 0 filtered) Number of infos : 1 ( 0 filtered) ERROR: XST failed Process "Synthesize" did not complete. **** end of error **** Do anyone know how to solve this ?