When I use Modular Design, the following NGDBuild command line is run on an NGC netlist:
ngdbuild -modular initial design_name
This does not create an NGO file as it does when an EDIF netlist is used. Is this the correct behavior?
An NGO file is produced only if an EDIF netlist is used as the input to NGDBuild. The NGC netlist created by XST is already in Xilinx Database Format, and it does not need to be converted to an NGO file.