A systematic approach to the design of structures for addition and subtraction — Case of radix r = mk

Abstract

The results of Robertson concerning, a systematic approach to the design of Adder/Subtracter structures of radix r=2k, k ≥ I are generalised to cover all structures of radix r = mk, k ≥ I and m ≥ 2 The use of Quasi binary representations help reduce the number of types of fundamental structures required. In addition to the types encountered in the earlier case, only one new type of fundamental structures called Radix-m Carry Generator is needed. Examples in the particular case of Decimal Adder/Subtracter structures are used to illustrate the results.