Gradient-Based Optimization of Custom Circuits
Circuit optimization is an essential part of custom, high-performance digital design. This presentation will summarize the circuit tuning efforts of our group at IBM Research over the past three years. Three main topics will be covered. In the first part, event-driven simulation and incremental, time-domain sensitivity computation will be described. The gradient computation forms the underpinning of all our circuit optimization methods. The application of the well-known direct and adjoint methods to event-driven timing simulators will be discussed. In the second portion of the presentation, dynamic tuning or the optimization of circuits based on time-domain simulation will be discussed. The user is required to provide input patterns and only measurements that are actuated during the transient simulation are optimized. The final topic is static tuning, wherein all paths through the logic are simultaneously optimized on a static-timing basis. Recent static tuning results will be presented. The impact of these tools on design methodology will also be discussed.
The slides of the talk in postscript.
Some recent papers relevant to the talk: