Xilinx V2.1 manual Using Black Boxes, Installed System Generator directory, A Black Box Example

Models: V2.1

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Installed System Generator directory

Xilinx System Generator v2.1 Reference Guide

Installed System Generator directory

The installer will create the following directory structure on your PC:

xilinx/

sysgen/

bin

examples

help

scripts

vhdl

These directories contain the following:

bin - This is the location of all system files. You should not add, delete, or change files in this subdirectory.

examples - This subdirectory contains examples that show how to run the software. This subdirectory also includes demonstration projects which show proper use of some of the Xilinx blocks.

help - The System Generator documentation (.pdf files, viewable in Adobe Acrobat) is located here.

scripts - This directory contains auxiliary Perl scripts which are used by the System Generator. These scripts are described in Chapter 6 of this document.

vhdl - This directory contains a library of core VHDL files used to construct your System Generator design.

Using Black Boxes

There are times when a design must include subsystems that cannot be realized with Xilinx blocks. For example, the design might require a FIR filter whose capabilities differ from those in the filter supplied in the Xilinx Blockset. Black boxes provide a way to include such subsystems in designs otherwise built from Xilinx blocks. To add a black box to a design, do the following:

Implement the subsystem (your black box) in Simulink. The subsystem can contain any combination of Xilinx and non-Xilinx blocks.

Place the Xilinx Black Box token at the top level sheet of the subsystem. This indicates to System Generator that the user will provide the VHDL or Verilog HDL necessary to implement that subsystem.

Double-click on the token to open the Black Box block parameters dialog box. Enter the information that describes the black box.

You must manually enter your VHDL or Verilog HDL black box files into your downstream software tools project after you run the System Generator code- generation step.

A Black Box Example

The directory: /xilinx/sysgen/examples/black_box, ordinarily stored in $MATLAB/toolbox) contains an example showing how to use black boxes.

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Xilinx Development System

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Xilinx V2.1 manual Using Black Boxes, Installed System Generator directory, A Black Box Example, Xilinx Development System