Design space exploration of parametric pipelined designs

This paper shows how a general form of algorithms consisting of a loop with loop-carried dependencies of one can be mapped to a parametric hardware design with pipelining and replication features. A technology-independent parametric model of the proposed design is developed to capture the variations of area and throughput with the number of pipeline stages and replications. This model allows rapid optimisation of design parameters by a few pre-synthesis operations. We present an optimisation process based on this model, and apply it to a Montgomery multiplier implementation on a Xilinx XC5VLX50T FPGA. Our approach is shown to be capable of accurately predicting the values of the parameters that maximise the throughput of the multiplier. In particular, up to 6.5 times fewer synthesis operations are required when compared with a complete search through the design space of the multiplier. This would speed up the synthesis process by 14 times, saving more than 23 hours of development time.