The Wallace Tree Simulator

John D. Carpinelli, Michael Dokachev

Research output: Contribution to journalConference articlepeer-review

1 Scopus citations


Wallace Trees are combinatorial logic circuits used to multiply binary integers. Constructed using carry-save adders, they are a fast, efficient method to implement multiplication. Since these adders do not propagate carry values between bits, they are faster than parallel adders and can produce multiplication products faster than other multiplication hardware. This paper presents the Wallace Tree Simulator, an instructional aid for students studying computer architecture and CPU design, typically at the junior or senior level. It simulates 4-, 6-, and 8-bit Wallace Tree multipliers, as presented in the textbook Computer Systems Organization and Architecture. Students select the size of the Wallace Tree to be simulated and enter values for the operands to be multiplied. The simulator shows the partial products generated by the Wallace Tree, and the results generated by each carry-save adder in the tree, as well as the final product. Students can also examine the internal organization of the carry-save adders to see how they generate their results within the tree. The Wallace Tree Simulator is coded as a platform-independent Java applet that can be executed within any Java-enabled web browser. The simulator and its source code are freely available under the terms of the GNU Public License.

Original languageEnglish (US)
Pages (from-to)2903-2909
Number of pages7
JournalASEE Annual Conference Proceedings
StatePublished - 2003
Event2003 ASEE Annual Conference and Exposition: Staying in Tune with Engineering Education - Nashville, TN, United States
Duration: Jun 22 2003Jun 25 2003

All Science Journal Classification (ASJC) codes

  • General Engineering


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