osstalk Cancellation for Realistic PCB BusesCrosstalk Cancellation for Realistic PCB Buses

摘要

We present a method for synthesizing crosstalk cancelling equalization filters for off-chip buses. Our approach is based on linear programming and allows direct optimization of the eye mask as well as controlling maximum filter output and maximum overshoot at the receiver. While the linear program formulation is flexible and straightforward, the resulting linear programs are quite large. We present an implementation of Mehrotras interior point method that exploits the structure and sparsity of our problem, enabling the practical synthesis of filters for large buses. As an example, we show a 32-bit bit bus with tight wire spacings. Using our filters, we achieve 7.5 times the bandwidth of a bus with no equalization, and 5 times the bandwidth of a bus with single-line pre-emphasis.