Full-custom VLSI design of a new high-speed modular adder structures

The design of a high-speed modular adders is an important issue in implementing online computations for many digital signal processing applications. The rapid advances in VLSI technology is, also, a driving force in realizing efficient hardware for these applications. In this paper, two new structures for a modular adder, along with their hardware implementations, are presented. The new hardware consists, basically, of carry-save adders, a simple combinational circuit, and carry-lookahead adders. The introduced adders have been implemented using full-custom design. Areas and time delays of these new structures are presented. Compared with the most recent published work, the time delay of the new adders is, significantly, less than other reported ones