BORG: A Reconfigurable Prototyping Board using Field-Programmable Gate Arrays

Field-Programmable Gate Arrays (FPGA) provide a medium to accelerate the process of prototyping digital designs. For designs with multiple FPGAs that need to be connected together, the bottleneck is now the process of wire-wrapping, bread-boarding, the construction of a printed circuit board, or the construction of a multi-chip module, which cannot be carried out until all FPGA designs are routed. It is because locking or preassigning I/O blocks often prevent FPGA placement/routers from completing the routing. We exploit the reprogrammability of FPGAs and use them for routing. To experiment with the idea, we constructed a PC-based prototyping board that contains two "user" FPGAs, two routing FPGAs, and a fifth FPGA that implements the glue logic to the PC bus. To facilitate the design process using the new prototyping board, we developed algorithms and tools that automatically configure the routing FPGAs. We describe the options that we have examined during the development of this boar..