Fatal errror in ISE 6.3 i

I would start at having a closer look at the synthesis report file. Most of the time when something like that happens there are earlier error or warning messages that could hint at what's really wrong. You can open the synthesis report either in ISE (but there the function to display it usually only works when there are no fatal erros) or by opening the

*.syr-file ISE creates in your project directory with a text editor.

Maybe there are some clues there. Otherwise, there's really not much you can do... FATAL_ERRORS are supossed to only show up when there's something really terribly wrong somewhere... Mostly, bugs in the software...

Plus, have you looked at Xilinx Answer Records on

? This looks similar to your problem, although the ISE version doesn't match:

cu, Sean

This is a known issue in ISE 6.3i and was partially fixed in 7.1i

if you are using timing driven packing and placement, turn off "register duplication".

if this does not help, turn off "timing driven packing and placement"

if this still does not help, try turning "keep_hierarchy" to "yes"

Vladislav

Thanks a lot Valdislav and Sean. You people made my day.

Regards Williams