Applications of network coding in global routing

We study the applications of the network coding technique for interconnect optimization and improving the routability of VLSI designs. Network coding technique generalizes the traditional routing approach by enabling the intermediate nodes to generate new signals by combining the signals received over their incoming wires. This is in contrast to the traditional (routing) approach, in which each intermediate node can only forward the incoming signals. While the traditional methods of interconnect routing have attracted a large body of research, applications of network coding in VLSI design have received a relatively little interest from the research community. Accordingly, in this paper we focus on establishing efficient coding networks for VLSI designs. The paper makes the following contributions. First, we extend the Hanan theorem for multi-net rectilinear coding networks. Second, we present several heuristic solutions for finding near-optimal coding networks. Finally, we perform an extensive simulation study to evaluate the advantage of network coding over the traditional routing solutions and to identify routing instances where the network coding techniques are expected to be beneficial. Our results show that network coding can help to reduce the required wirelenght, in particular in the congested areas and in the presence of blockages.