Experimental evaluation and comparison of latency-optimized opticaland conventional multi-FPGA systems

Rising data rates and input/output density in integrated circuits are challenging the traditional off-chip copper interconnect solutions, demanding a compatible high-speed serial interface capable of maintaining multi-gigabits data rates. Designers typically choose copper interconnect for chip-to-chip connections in a Multi-FPGA System (MFS). However, copper based interconnects are incapable of scaling up with the data rate and exhibit lossy characteristics with increasing frequency. Performance of an MFS can be enhanced if the off-chip electrical interconnects are replaced by short-range optical interconnects. Additionally, the selection of MFS inter-chip communication strategy also affects system performance. We have proposed latency-optimized MFS with serial optical interface with two different inter-chip communication strategies. The proposed architectures were experimentally evaluated using six real world benchmark circuits and provided an average system frequency gain of nearly 22%, compared to conventional MFS.