Timing and Congestion Driven Algorithms for Fpga Placement

Placement is one of the most important steps in physical design for VLSI circuits. For field programmable gate arrays (FPGAs), the placement step determines the location of each logic block. I present novel timing and congestion driven placement algorithms for FPGAs with minimal runtime overhead. By predicting the post-routing timing-critical edges and estimating congestion accurately, this algorithm is able to simultaneously reduce the critical path delay and the minimum number of routing tracks. The core of the algorithm consists of a criticality-history record of connection edges and a congestion map. This approach is applied to the 20 largest Microelectronics Center of North Carolina (MCNC) benchmark circuits. Experimental results show that compared with the state-of-the-art FPGA place and route package, the Versatile Place and Route (VPR) suite, this algorithm yields an average of 8.1% reduction (maximum 30.5%) in the critical path delay and 5% reduction in channel width. Meanwhile, the average runtime of the algorithm is only 2.3X as of VPR. ACKNOWLEDGMENTS I have been fortunate to have my parents over the past 28 years. They always support me whenever I was ambitious or in depression. Without them, I can never be strong enough to stand success and failure. I dedicate this thesis to them. I joined the department of computer science and engineering of UNT in Fall 2005. From that moment, I received great help from a lot of professors and friends. Dr. Hao Li is my major professor who taught me a lot in the field of VLSI CAD. His encouragement and invaluable advice really motivated me to work hard on research and this thesis. Dr. Farhad Shahrokhi, who impressed me by his profound knowledge, gave me a lot of insight into graph theory. He spent much time attending the events hosted by the Chinese Student and Scholar Association. R. Mikler improved my understanding of compiler, programming languages and operating system. Dr. Saraju P. Mohanty shared tips of writing a paper with me. I am grateful to all of them. I also appreciate my friends who helped me and shared my happiness. I am thankful to friends are my great fortune. I will never forget this precious period we enjoyed together. ii CONTENTS ACKNOWLEDGMENTS ii LIST OF TABLES v LIST OF FIGURES vi