In EPIC, I can see/edit wide-edge decoders for Spartan and Spartan-XL devices despite the fact that, according to the documentation, Spartan and Spartan-XL devices do not have wide-edge decoders.
解决方案
Spartan and Spartan-XL devices had the EPIC templates copied over from the 4K series. The existance of the wide-edge decoders in the EPIC tool is a bug.
However, as stated in the data sheets and documentation, the decoders should not be there.