Simulation-based synthesis, however, poses significant challenges. Commercial simulators are not designed to be invoked 50,000 times in any optimizer loop. I will describe a synthesis methodology and new global search algorithms that are efficient enough to allow full circuit simulation of each solution candidate, yet robust enough to find good solutions for difficult circuits.
Finally, to counter the criticism that analog synthesis can never scale to cope with the complexity of industrial designs, I will show how the use of appropriate macromodeling techniques allows us to attack complex analog blocks. I will describe how we resynthesized from scratch, in several different styles, the equalizer/filter block from the frontend of Texas Instrument's production ADSL CODEC [Hester et al, ISSCC99] and verified that our designs matched TI's original specifications. This is the largest manual-vs-synthetic controlled experiment ever undertaken with a state-of-the-art design. Coupled with emerging commercial tools for analog physical synthesis, I will argue that we are finally able to consider synthesis of nontrivial blocks of analog IP.
About the speaker:
Rob Rutenbar received the Ph.D. in Computer Engineering from the University of Michigan in 1984, and subsequently joined the faculty at Carnegie Mellon, where he is currently Professor of Electrical and Computer Engineering. He has worked on analog circuit and physical synthesis since the Reagan administration. In his copious spare time, he cofounded Neolinear, and currently serves as its Chief Scientist.
Contact information:
Rob A. Rutenbar
Dept of Electrical and Computer Engineering
Carnegie Mellon University
Pittsburgh, PA 15213
412 268 3334
412 268 2859
rutenbar@ece.cmu.edu