Wide word‐length carry‐select adder design using ripple carry and carry look‐ahead method based hybrid 4‐bit carry generator

Approximate Ripple Carry and Carry Lookahead Adders - A Comparative Analysis

Approximate ripple carry adders (RCAs) and carry lookahead adders (CLAs) are presented which are compared with accurate RCAs and CLAs for performing a 32-bit addition. The accurate and approximate RCAs and CLAs are implemented using a 32/28nm CMOS process. Approximations ranging from 4to 20-bits are considered for the less significant adder bit positions. The simulation results show that approx...

Variable delay ripple carry adder with carry chain interrupt detection

Various implementations are known for the efficient implementation of adders. As opposed to traditional optimization techniques a statistical approach using early termination detection is used in this article to obtain efficient implementations for large operands. The completion detection logic is described and the efficiency of the approach is shown and analyzed analytically and through comput...

Circuit Design for A Measurement-Based Quantum Carry-Lookahead Adder

We present the design and evaluation of a quantum carry-lookahead adder (QCLA) using measurement-based quantum computation (MBQC), called MBQCLA. QCLA was originally designed for an abstract, concurrent architecture supporting long-distance communication, but most realistic architectures heavily constrain communication distances. The quantum carry-lookahead adder is faster than a quantum ripple...

Optimized structures of hybrid ripple carry and hierarchical carry lookahead adders

Design of Ripple Carry Adder using Quantum Cellular Automata

Quantum Cellular Automata (QCA) is one of the emerging nanotechnologies in which it is possible to implement reversible logic gates. QCA makes it possible to achieve high performance beyond the limits of existing CMOS technology. QCA does not have to dissipate its signal energy during transition. Further, there is no movement of electrons from one QCA cell to the other, there is no current flow...