Comparative Design of 16-Bit Sparse-Tree Rsfq Adder

In this paper, we propse 16-bit sparse tree RSFQ adder (Rapid single flux quantam), kogge-stone adder, carry lookahead adder. In general N-bit adders like Ripple carry adder s(slow adders compare to other adders), and carry lookahead adders(area consuming adders) are used in earlier days. But now the most of industries are using parallel prefix adders because of their advantages compare to kogge-stone adder, carry lookahead adder, Our prefix sparse tree adders are faster and area efficient. Parallel prefix adder is a technique for increasing the speed in DSP processor while performing addition. We simulate and synthesis different types of 16-bit sparse tree RSFQ adders using Xilinx ISE10.1i tool, By using these synthesis results, We noted the performance parameters like number of LUT’s and delay. We compare these three adders interms of LUT’s represents area) and delay values. Keywords—digital arithmetic, RSFQ adder, kogge-stone adder ,carry operator, prefix adder.