General Description: I am using Synplicity 5.1.2, with a top-level EDIF (dakota.edf) with 9 lower-level macros. NGDBuild hangs when it checks the expanded design. (The same behavior occurs on both PC and Solaris machines.)
Why does this error occur?
Synplicity 5.1.2 is incorrectly placing an inverter with the signal name the same on both the input and output, which causes DRC to fall into an infinite loop.
The recommendation is to upgrade your version of Synplicity to a newer version.