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AR# 17454

11.1 RTL/Technology Viewer - In the RTL Viewer an instantiated core does not appear to be connected


When I view a schematic of my design in the RTL Viewer, a core that was instantiated in the design does not show nets connected to the symbol representing the core.


This is typically a visual-only problem that occurs during the creation of the RTL schematic.

To verify that a core has been connected correctly after implementation, use the FPGA Editor.

If you are using ISE design tools 6.2i or earlier, a possible cause of the "missing nets" in the RTL view is related to the "Read Cores" option for XST. When this option is selected ("On"), the core will not be connected in the RTL view. You can resolve this issue by unchecking this option and running synthesis again. After you perform these steps, the core will be connected.

If you are experiencing this problem while using the latest software version, please report any missing or incorrect connections to Xilinx Technical Support and provide a test case if possible.

AR# 17454
Date Created 09/03/2007
Last Updated 12/15/2012
Status Active
Type General Article
  • ISE Design Suite - 11.1