An FPGA-based soft multiprocessor system for IPv4 packet forwarding

To realize high performance, embedded applications are deployed on multiprocessor platforms tailored for an application domain. However, when a suitable platform is not available, only few application niches can justify the increasing costs of an IC product design. An alternative is to design the multiprocessor on an FPGA. This retains the programmability advantage, while obviating the risks in producing silicon. This also opens FPGAs to the world of software designers. In this paper, we demonstrate the feasibility of FPGA-based multiprocessors for high performance applications. We deploy IPv4 packet forwarding on a multiprocessor on the Xilinx Virtex-II Pro FPGA. The design achieves a 1.8 Gbps throughput and loses only 2.6X in performance (normalized to area) compared to an implementation on the Intel IXP-28OO network processor. We also develop a design space exploration framework using integer linear programming to explore multiprocessor configurations for an application. Using this framework, we achieve a more efficient multiprocessor design surpassing the performance of our hand-tuned solution for packet forwarding.