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AR# 13867

8.1i NGDBuild - "ERROR:NgdBuild:604 - %s block '%s' with type '%s' is unexpanded. Symbol '%s' is not supported in target '%s'.Xvendor=%s Xleid=%d Xhiername=%s"


Why do I receive the following error in NGDBuild?

"ERROR:NgdBuild:604 - %s block '%s' with type '%s' is unexpanded. Symbol '%s' is not supported in target '%s'.Xvendor=%s Xleid=%d Xhiername=%s"


Make sure that each module or macro that is called out or used by the top-level design or netlist is located in the same working directory. Also, check to ensure that the signal names on the module or macro match the signal names in the top-level design or netlist.


If you generated a DCM module using Architecture Wizard and the design synthesized successfully, try removing the "xxxxx.xaw" and use "xxxxx.vhd" ("xxxxx.vhd" should be in the project directory). If "xxxxx.vhd" is not in this directory, generate the VHDL source for "xxxxx.xaw". After you generate the VHDL source, follow these steps:

1. Right click "xxxxx.xaw" and click Remove.

2. Select Project -> Add Source.

3. Select "xxxxx.vhd" from your project directory.


If you instantiated an IBUFDS_LVPECL_25 or an OBUFDS_LVPECL_25, you must instantiate an IBUFDS or an OBUFDS. Setting the IOSTANDARD in the generic map or in the UCF file (see below) solves the problem:


generic map (


port map (

O => out_p,

OB => out_n,

I => in_ds



If you are running a Modular Design Flow, you should treat this warning as an error condition that will break the implementation flow in downstream tools.

The warning means that you have an unexpanded block inside the active module. This must be fixed before you proceed with your design (this situation generally occurs if the netlist for the "logical block" is not available).

To fix the problem, provide the netlist (EDIF, NGO, or NGC file) in the active module directory, and rerun the active module implementation.


If you are running EDK with ISE, make sure that your installation of ISE is in a path that does not contain spaces. For additional EDK information, see (Xilinx Answer 21864).


NGDBUILD issues this error when it cannot resolve all of the components/modules for the entire design.

For example, assume you have an HDL design that instantiates black-box modules, and the module description for these black-boxes is contained in an EDIF file. If the EDIF file is not in the macro search path or the project directory, NGDBuild issues this error.

This issue is often observed in designs containing CORE Generator modules in which the CORE Generator files are maintained in a remote directory.

To avoid this problem, verify that the module description file has the correct name and is located in the macro search path or project directory. See (Xilinx Answer 11701).


These errors are generated when NGDBuild cannot find the netlist for the PCI Core. The netlist for the PCI Core is called "pci_lc_i.ngo." See (Xilinx Answer 10235).

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AR# 13867
Date 12/15/2012
Status Active
Type General Article