A Novel Decimal Logarithmic Converter Based on First-Order Polynomial Approximation

This paper presents a decimal logarithmic converter based on the decimal first-order polynomial (linear) approximation algorithm. The proposed approach is mainly based on a look-up table, followed a decimal linear approximation step. Compared with a binary-based decimal linear approximation algorithm (Algorithm 1), the proposed algorithm (Algorithm 2) is error-free in the conversion between the decimal and the binary formats. The proposed architecture is implemented by the combinational logic in the binary coded decimal (BCD) encoding on Virtex5 XC5VLX110T FPGA. The results of the comparison show that the hardware performance of Algorithm 2 can run 2.15 times faster than Algorithm 1, with the expense of 1.14 times more area.