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Direct Window Bridge

Direct Window Bridge

Last Updated

November 8, 2011


The direct window bridge peripheral contains a slave interface that passes Avalon MM read and write transactions thru to its master’s interface. The slave interface therefore provides a “window” into the address map of the master interface. The base address of this “window” into the master’s address map is provided by an “index” register located thru a second control slave interface.

1/1e/Dwb_1.PNG ( Dwb 1.PNG - click here to view image )

The direct window bridge peripheral can be configured to map a single window into the master’s address map, or multiple sub-windows into the master’s address map. When multiple sub-windows are enabled, additional “index” registers are available to set the mapping of the sub-window into the master’s address map.

b/be/Dwb_2.PNG ( Dwb 2.PNG - click here to view image )

The parameterization GUI for this component.

7/78/Dwb_gui.PNG ( Dwb gui.PNG - click here to view image )


This example consists of an archive of the source material to build the entire hardware and software projects required to execute the example in ModelSim. There is also a PDF file that documents how this example is put together and the high level functionality that it performs.


Archive Download and Extraction

Download the archive for this example and place it in a directory on your system that does not include spaces in the path name. The entire path name of this directory must not contain spaces, so on Windows systems you should avoid putting this in the "My Documents" folder, or on your "Desktop" since these locations are subdirectories of the "Documents and Settings" path, and that would mean that these locations inherit the spaces in that part of the path name.

In order to extract the archives after downloading them, it is recommended that you run the "tar xzf <filename>" command from a bash shell. For linux users you should have ready access to a bash shell. For windows users, you may need to install the Altera development tools to gain access to a bash shell. On Windows it is recommended that you install the complete Altera ACDS development tools which includes the Nios II EDS development tools. Once these tool chains are properly installed on your workstation, you can launch a bash shell by running:

"Start -> Programs -> Altera -> Nios II EDS X.x -> Nios II X.x Command Shell"

Once you are in the bash shell, you can "cd" into the directory containing the archives that you've downloaded, and running the following command to extract them:

tar xzf <archive_filename>

Note that if you use some other archiving software to extract these archives, like WinZip, you may lose the execution privileges on some of the shell scripts within the archives that are used to perform various activities associated with building and using the example. If this happens, you can restore execute privileges from within a bash shell with the command "chmod +x <filename>". It is recommended that you avoid this situation by using "tar" to extract the archives from within a bash shell and avoid using any Windows oriented archive utilities with these archives.

Building the example.

Once the archive is extracted, you should locate a readme.txt file in the top level of the archive directory. Read the contents of that file for additional information about building and running the example.


The current version of this example was tested with the Altera ACDS 11.1 development tools.

Previous versions were created and tested with the Altera ACDS 11.0sp1 development tools.

See Also

ST2MM Bridge

Update History

20111108 – updated example to support ACDS 11.1. TCL scripts used to build the ModelSim simulation examples were updated to support the 11.1 environment.

20111106 – added a GUI field to the component to allow the user to set the maximumPendingReadTransactions property for the bridge slave.

Outdated Releases

·      20111106_direct_window_bridge_11.0sp1.tgz

·      20111029_direct_window_bridge_11.0sp1.tgz

© 2011 Altera Corporation.

The material in this wiki page or document is provided AS-IS and is not

supported by Altera Corporation. Use the material in this document at your own

risk; it might be, for example, objectionable, misleading or inaccurate.

Version history
Last update:
‎06-26-2019 05:01 AM
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