PROJECT TITLE :

Variable Latency Speculative Han-Carlson Adder

ABSTRACT:

Variable latency adders are recently proposed in literature. A variable latency adder employs speculation: the exact arithmetic function is replaced with an approximated one that is faster and provides the proper result most of the time, however not invariably. The approximated adder is augmented with a mistake detection network that asserts a slip-up signal when speculation fails. Speculative variable latency adders have attracted sturdy interest thanks to their capability to cut back average delay compared to ancient architectures. This paper proposes a novel variable latency speculative adder primarily based on Han-Carlson parallel-prefix topology that resulted a lot of effective than variable latency Kogge-Stone topology. The paper describes the stages in that variable latency speculative prefix adders will be subdivided and presents a unique error detection network that reduces error likelihood compared to previous approaches. Many variable latency speculative adders, for varied operand lengths, using both Han-Carlson and Kogge-Stone topology, are synthesized using the UMC sixty five nm library. Obtained results show that proposed variable latency Han-Carlson adder outperforms each previously proposed speculative Kogge-Stone architectures and non-speculative adders, when high-speed is required. It is additionally shown that non-speculative adders remain the most effective selection when the speed constraint is relaxed.