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AR# 39980

Design Assistant for XST - Help instantiating black boxed components

Description

Please refer to this answer record for help instantiating black boxed components.

Note: This Answer Record is a part of the Xilinx Solution Center for XST (Xilinx Answer 38927) The Xilinx Solution Center for XST is available to address all questions related to XST. Whether you are starting a new design or troubleshooting a problem, use the Solution Center for XST to guide you to the right information.

Solution

Below is a checklist to verify when instantiating a black boxed component in VHDL or Verilog. This is only done if you have a netlist (NGC, NGO, or EDF) that represents the blackbox:

VHDL:
  • Ensure that the port names are consistent between the component declaration and the instantiation.
  • Ensure that the port widths are consistent between the component declaration and the instantiation.
  • Ensure that the port directions are consistent between the component declaration and the instantiation.
  • Ensure that semicolons are placed after every port except for the last port in the component declaration.
  • Ensure that commas are placed after every connection in an instantiation except for the last connection.
  • Capitalization only matters if you are instantiating a Verilog module in VHDL.
  • In the instantiation, remember that the instance name is before the colon. The component name comes after the colon.
  • Component declarations are either placed in a package, or in the same file as the instantiation between the architecture and begin statement.
Verilog:
  • Capitalization must be consistent
  • A module declaration without any synthesizable code must also be compiled so that XST knows the port information.
  • Ensure that the port names are consistent between the declaration and the instantiation.
  • Ensure that the port widths are consistent between the declaration and the instantiation.
  • Ensure that the port directions are consistent between the declaration and the instantiation.
  • Ensure that commas are placed after every connection except for the last connection.
  • In the instantiation, remember that the component name comes before the instance name.
Also remember that XST can read your black boxed component and include all of the statistics into the Final Report. XST has an option called "Read Cores" that enables this.

If an instance is not intended to be black boxed. Please see (Xilinx Answer 40787)

Linked Answer Records

Master Answer Records

Answer Number Answer Title Version Found Version Resolved
38927 Xilinx Solution Center for XST N/A N/A

Associated Answer Records

AR# 39980
Date Created 03/15/2011
Last Updated 02/12/2013
Status Active
Type General Article