Sign Bit Reduction Encoding For Low Power Applications

Abstract

In this paper, a low power technique, called SBR (Sign Bit Reduction), which reduces the energy consumption in multipliers as well as data buses is proposed. The technique reduces the number of sign bits in the data transfer as well as in the multiplication process. This feature enables us to use the encoding technique for both the transfer of the data and its multiplication at the destination without any need for an intermediate decoding step. Simple circuits are used as the SBR decoder and encoder. The efficacy of the technique is evaluated for both voice and random data. The results of applying the voice data to a 16-bit multiplier implemented with this scheme shows energy consumption up to 11.4% compared to those of a 2's complement implementation, while the number of required clock periods for the multiplication process is reduced up to 14.5%. The results of applying the SBR technique to a 30-tap FIR filter show up to 9.6% reduction in the energy consumption and up to 13.4% reduction in the required clock cycles. Finally, for voice data and random inputs, the use of the technique for a 16-bit data bus leads to an average energy consumption of up to 14.6%.