Static window addition: A new paradigm for the design of variable latency adders
Kai Du, Peter Varman, Kartik Mohanram · 2011
Speculative adders have attracted strong interest for achieving sublogarithmic delays by exploiting the tradeoffs between correctness and performance. Speculative adders also find use in the design of error-free variable latency adders, which combine speculation with error correction to achieve high performance for low area overhead over traditional adders. This paper describes static window addition (SWA), a novel function speculation technique for the design of low overhead, high performance variable latency adders. Analytical models for the error rate of SWA-based speculative adders are developed to facilitate both design exploration and convergence. We show that on average, variable latency addition using SWA-based speculative adders is 10% faster than the fastest DesignWare adder with area requirements of -5 to 40% for different adder widths.