Modular Adder Designs Based On Thermometer Coding And One-Hot Coding

Modular adders are used in various applications of computer systems. Modular addition is commonly used in residue number system processors. It is used mainly in the residue arithmetic unit and also in both the forward and reverse converters. Residue number system is highly efficient when compared with positional number system, because it provides high speed computation as well as less area requirement. In order to improve the computation speed, efficient modular adders are required. Modular adders based on thermometer code residue and one hot code residue are used for this purpose. This results in less latency and area. This approach reduces the area and delay of modular adders since there is no carry bit propagation during modular addition operation. It also simplifies the structure of modular adders compared to conventional binary based modular adders. All the proposed modular adders are described in verilog HDL and verified using Xilinx ISE.