MIXED-RADIX CARRY-LOOKAHEAD ADDER ARCHITECTURE

摘要

Embodiments described herein are directed to mixed-radix carry-lookahead adders and methods performed thereby. The mixed-radix carry-lookahead adder includes an multiple carry-lookahead stages, where each stage may be of a different radix. Each stage operates on input bits, creating and implementing propagate and generate signals for each bit. The carry-lookahead stages also compute an XOR of the inputs that is forwarded to a final carry-lookahead stage. The elements of the initial and subsequent carry-lookahead stages are arranged such that each of the propagate and generate output signals passes through a minimal number of passive transmission lines. The final stage of the mixed-radix carry-lookahead adder includes an XOR logic gate configured to receive the generate output from an intermediate carry-lookahead stage and XOR the generate output received from the intermediate carry-lookahead stage with the computed XOR signal forwarded from the initial carry-lookahead stage to produce a sum of the input bits.