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AR# 61294

Vivado - link_design fails when the EDIF file name does not match module/entity name - ERROR: [DRC 23-20] Rule violation (INBB-3) Black Box Instances


In my Vivado project I have a design with an EDIF submodule.

If the EDIF file name does not match the module/entity name, Vivado and "link_design" fail to recognize the module.

As a result, the module is not resolved and remains as a black box.

ERROR: [DRC 23-20] Rule violation (INBB-3) Black Box Instances - Cell '<cell name>' of type '<cell type"' has undefined contents and is considered a black box. The contents of this cell must be defined for opt_design to complete successfully.


Vivado tools look for a netlist file with the module name.

The content of the EDIF (.edn or .edf) is not parsed to determine if the internal module name matches one that Vivado tools are looking for.

There are two way to work around this issue:

  • Change the EDIF file name to use the same name as the module/entity name (or alternatively, edit the EDIF content so that the file and module name match).
  • The user can add an attribute "FILE" with the value of the base name of the file containing the top module that would replace the blackbox.
    This attribute needs to be attached to the blackbox module. 
    For example, adding the attribute "FILE" with the value "my_edn_file" can be attached to the black box module "top_mod".
    Vivado will look for my_edn_file.edf file to fill in the blackbox. 
AR# 61294
Date 08/31/2017
Status Active
Type General Article
  • Vivado Design Suite
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