Reversible Logic Synthesis Benchmarks Page

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RCViewer

A simple application to view reversible circuits

Version 1.14

RCViewer is intended to be a simple application to aid in the visualization of reversible quantum circuits made up of Toffoli and Fredkin gates in cascade format. Currently it will display a simple image for a given circuit, and for now can save this image as a bitmap file. More gate support and more image format support is planned for the future.

RCViewer was written in C++ using the Windows Template Library, and so is currently available only for the Win32 platform.

RCViewer is free to distribute, although if you choose to distribute it over a web page, or some other large-scale form of distribution, I would appreciate it if you dropped me a note at y8ju8@unb.ca to let me know. Neither myself nor UNB will accept any responsibility for any harm caused by this program or the transfer thereof.

Features:

Circuit types:

Currently limited to cascades of generalized Toffoli and Fredkin gates.
Custom file format (.tfc). Syntax is provided with the sample .tfc files.

Image exporting:

Currently can save the circuit image as a 24-bit Bitmap file.

Quantum Cost:

Calculates the quantum cost of the circuit based on the latest table .

Output verification:

View the output of a circuit in truth-table form
Verify the output of a circuit against a PLA file

Customization:

Can change the appearance of the circuit by altering the colors, size, and spacing of gates.

Instructions

Everything is pretty simple and straightforward.

To open a circuit for viewing, click the folder icon on the toolbar (folder image), or select File/Open... from the menu bar, or use the shortcut: Ctrl-O. By default, files with the extension of .tfc ("Toffoli-Fredkin Cascades") are listed, but any file extension is valid and will be attempted to be parsed. Error messages will alert you to any parse errors.

To save a bitmap image of an open circuit, click the disk image icon on the toolbar, or select File/Save BMP... from the menu bar, or use the shortcut: Ctrl-S. The image will be saved as a 24-bit bitmap file. If no circuit has been opened, or if the circuit is empty (0 gates), this button does nothing.

To change the look of the circuit, select Edit/Preferences... from the menu bar, or use the shortcut: Ctrl-E. Here you can change the:

Colors. Separate colors can be chosen to draw: variable names, constant values, garbage output, the lines themselves, gates, and the background color. Now you can show off your circuits in stylish hot-pink on yellow background, should you so desire!
Sizes and spaces. Change the size of: target symbols, control symbols. Change the space: between lines (vertical), and between gates (horizontal).
Ordering. Have the variables drawn from top-to-bottom (in the order specified in the tfc file) or from bottom-to-top.

To view the I/O of a circuit, click on the "IO" button on the toolbar, or select View/Input/Output from the menu bar, or use the shortcut: Ctrl-I. Input values are listed ignoring the constant input lines, and output values are listed ignoring the garbage output variables.

To compare the output of a circuit to a PLA file, click the "PLA" button on the toolbar, or select File/Verify With PLA... from the menu bar. The program will try and match output variables from the currently opened circuit to the output lines from the chosen PLA file. If successful, the program will report which Circuit output lines map to which PLA output lines. Otherwise, the program will report that the circuit and PLA files do not have equivalent output.

To view the cost statistics of an open circuit, click the "Q" icon on the toolbar, or select View/Quantum Cost, or use the shortcut: Ctrl-Q. A message box will appear, telling you: the gate count of the circuit, the number of garbage bits, and the estimated quantum cost taken from the latest tables.

The circuit image will wrap if it is longer than the window's width (as well as a bit of bordering space.) However, if the window is too small (narrower than 200 pixels, technically,) the circuit will not be drawn at all. Saved bitmap files will appear exactly as they do in the window (only without any excess whitespace), so be sure to play with the window size and the preferences to produce the image you want.

Future plans:

Provide more image format options for saving
Clean up some of the code structure, open it up to allow for easy addition of gate types

Version History

1.0 - First version. Supports Toffoli and Fredkin gates only. Supports bitmap files for image saving. Can customize color and spacing of gates and lines.
1.01 - Added ParseException for including a .c list in the file when there are no constants expected. Added option to list variables from either top-to-bottom or bottom-to-top.
1.02 - Fixed silly bug when drawing Fredkin gates from bottom to top.
1.1 - Added Input/Output viewing and PLA file verification features.
1.11 - Improved PLA parsing. Sped up scrolling through IO for larger circuits. Tweaked default preferences.
1.12 - Reverted I/O viewing to text. Fixed some scrolling bugs.
1.13 - Optional Output variable tags added.
1.132 - The quantum cost table was updated based on the new results.
1.14 - The quantum cost table was updated based on the newer results.

Last updated: January 7, 2005
Author: Nathan Scott
Comments\Bugs? Email: y8ju8@unb.ca