Efficient hardware implementations of binary-to-BCD conversion schemes for decimal multiplication

This paper proposes two high performance binary-to-binary coded decimal (BCD) conversion algorithms for use in BCD multiplication. These algorithms are based on splitting the 7-bit binary partial product of two BCD digits into two groups, computing the contribution of each group to the equivalent BCD partial product, and adding these contributions to compute the final BCD partial product. Designs for the proposed architectures and their implementations targeting both ASIC and FPGA are compared with others. Implementations of BCD array multipliers using both our conversion circuits and existing conversion circuits have been performed. The synthesis results for both ASIC and FPGA show that the proposed designs are faster and occupying less area than the state-of-the-art conversion circuits. Furthermore, the results obtained from comparing BCD multipliers of various sizes show that the enhancement in the area of the conversion circuit grows into a sizable area improvement in the multiplier circuit.