ECE Senior Students Kevin Duh, Vernon Evans, Christopher Flesher, and David Suksumrit have received the department's senior design award for their project in VLSI Design, Elec 422 and Elec 423, entitled "Arbiter". This project is a custom VLSI application specific processor that can be used in control applications. The underlying arithmetic blocks in the VLSI chip use a concept called Fuzzy Logic.

The key challenges in implementing this processor were to integrate the multiple phases of the fuzzifier, inference engine, and defuzzifier into a single chip while controlling the complexity of each subunit. Kevin, Vernon, Chris, and David were very creative in understanding the algorithm and mapping it to basic arithmetic blocks. The completed chip had about 15,000 transistors and required extensive simulation to verify the logic and timing of the signals. The "Arbiter" design was fabricated by the MOSIS service in a 0.5 micron technology this winter.

The fabricated chips are back from MOSIS and they are currently doing exhaustive functional testing of the chip. They are evaluating the timing sensitivity of their VLSI chip design to the frequency of operation and are finding some interesting effects between simulation and a fabricated chip. The overall fuzzy controller chip is working as designed and Kevin, Vernon, Chris, and David have successfully verified the "Arbiter" functionality on many test cases.

The web page for their project is at http://www.owlnet.rice.edu/~davids/vlsi/ and a plot and photograph of the completed chip are at http://www.ece.rice.edu/~cavallar/elec422/03chip_photos/A-arbiter.jpg and http://www.ece.rice.edu/~cavallar/elec422/03chip_photos/A-arbiter1c1.jpg, respectively.

Last modified: April 21, 2003