The NGC files are in ASCII, non-readable format and as a result cannot be compared directly for verification purposes.
However, the NGC files can be compared in the following ways:
1. Convert the NGC file to a simulation model .v|.vhd file and then compare the Verilog/VHDL simulation models.
The simulation model can be generated in the following ways.
netgen -w -sim -ofmt vhdl|verilog <name>.ngc <name>_synthesis.vhd |<name>_synthesis.v
2. Convert from NGC to EDIF and compare the EDIF files.
To generate the EDIF file:
ngc2edif -w <name>.ngc <name>.edif