Parallel decimal multipliers using binary multipliers

Human-centric applications, like financial and commercial, depend on decimal arithmetic since the results must match exactly those obtained by human calculations. The IEEE-754 2008 standard for floating point arithmetic has definitely recognized the importance of decimal for computer arithmetic. A number of hardware approaches have already been proposed for decimal arithmetic operations, including addition, subtraction, multiplication and division. However, few efforts have been done to develop decimal IP cores able to take advantage of the binary multipliers available in most reconfigurable computing architectures. In this paper, we analyze the tradeoffs involved in the design of a parallel decimal multiplier, for decimal operands with 8 and 16 digits, using existent coarse-grained embedded binary arithmetic blocks. The proposed circuits were implemented in a Xilinx Virtex 4 FPGA. The results indicate that the proposed parallel multipliers are very competitive when compared to decimal multipliers implemented with direct manipulation of BCD numbers.