Speculative completion for the design of high-performance asynchronous dynamic adders

This paper presents an in-depth case study in high-performance asynchronous adder design. A recent method, called “speculative completion”, is used. This method uses single-rail bundled datapaths but also allows early completion. Five new dynamic designs are presented for Brent-Kung and Carry-Bypass adders. Furthermore, two new architectures are introduced, which target (i) small number addition, and (ii) hybrid operation. Initial SPICE simulation and statistical analysis show performance improvements up to 19% on random inputs and 14% on actual programs for 32-bit adders, and up to 29% on random inputs for 64-bit adders, over comparable synchronous designs