Design and analysis of FPGA/FPIC switch modules

Switch modules are the most important component of the routing resources in FPGAs and FPICs. The quality of switch modules greatly affects FPGA/FPIC routing solutions. The switch-module design problem was studied by K. Zhu et al. (1993). In order to analyze the routability of designed switch modules, a heuristic algorithm based on network-flow techniques was proposed. In this paper, we mathematically show that the network-flow based algorithm has provably good performance with the bounds 5 and 5/4 away from the optima for two types of switch modules, respectively. Based on the analyses, we developed a new method for designing switch modules. Experimental results show that our designed switch modules significantly improve routability, compared with those by K. Zhu et al. Extensive experiments also show that the network-flow based algorithm is highly accurate and runs very efficiently.