A change in MAP in 7.1i Service Pack 3 to fix an IBUFDS packing issue causes some designs to crash while the NCD is being written at the end of MAP.
"Release 7.1i - Map H.41
Copyright (c) 1995-2005 Xilinx, Inc. All rights reserved.
Using target part "2vp70ff1704-7".
Mapping design into LUTs...
Writing file test.ngm...
Running directed packing...
Running delay-based LUT packing...
Running related packing...
Writing design file "test.ncd"...
Segmentation fault (core dumped)"
This problem has been fixed in ISE version 8.1i.
For earlier ISE revisions, the problem can be avoided by setting the environment variable:
Linux and Solaris:
setenv XIL_MAP_ENABLE_OLD_SLAVE_IPAD 1
For general information about setting ISE environment variables, see (Xilinx Answer 11630).