A Novel Crossbar Scheduling for Multi-FPGA Parallel SAR Imaging System

In multiprocessors system, crossbar scheduling networks have been widely used for system interconnection among processors or modules in SOC (System on Chip). In this paper, a parallel SAR (Synthetic Aperture Radar) image processing system which is composed of five FPGA PE (Process Element)s is taken for the basic research platform. Then a novel compact crossbar scheduling network for multi distributed parallel PEs is proposed for communication among PEs. Different scheduling strategies are provided for different kinds of source data streams which are from external raw data and PEs. In addition, resynchronization makes data streams of all PEs synchronous when all data streams are not entirely consistent due to the efficiency of memory access and bus burst transfer. Simulation and synthesis show that only little device resource is utilized by the proposed crossbar scheduling network to meet the requirements of the system. The maximum throughout of the crossbar could be above 20Gbps when the operating frequency is 100MHz, and the minimum latency is three clock cycles. The proposed crossbar scheduling as a sub-module could be easily integrated into SAR real-time imaging system.