To create a lower-level netlist, set up a project with that netlist as the top-level module. Before you run synthesis, set the out-of-context (OOC) mode as shown This Figure.
In the More Options section, you can type -mode out_of_context to have the tool not insert any I/O buffers in this level.
After you run synthesis, open the synthesized design, and in the Tcl Console, type the write_edif Tcl command in the Tcl Console. The syntax is as follows:
write_edif <design_name>.edf