write_edif - write design to EDIF netlist file

    write_edif [options] [filename]

Write the current design to an EDIF netlist file.

    -top top_module
        set the specified module as design top module

    -nogndvcc
        do not create "GND" and "VCC" cells. (this will produce an error
        if the design contains constant nets. use "hilomap" to map to custom
        constant drivers first)

Unfortunately there are different "flavors" of the EDIF file format. This
command generates EDIF files for the Xilinx place&route tools. It might be
necessary to make small modifications to this command when a different tool
is targeted.