Design of Reversible Single Precision and Double Precision Floating Point Multipliers

Reversible logic preserves information and provides low power computing. Floating point multiplier is an important part of arithmetic in DSP applications. IEEE754 provide two basic and widely used formats for representing floating point numbers namely Single Precision Floating point (SPFP) and Double Precision Floating Point (DPFP). In this paper, we have proposed designs for Reversible SPFP and DPFP point multiplier which requires optimum design of 24X24 and 53X53 multiplying circuitry with reversible gates respectively. Also we presented sign bit calculation and exponent bit calculation circuits by reversible logic. Reversible Mantissa bits calculation circuitry requires consumes more area as it has large value of quantum cost and garbage outputs as compare to reversible sign bit and exponent bits calculation circuitry. So, we mainly focused our work on to minimize the area consumed by the reversible mantissa bits calculation circuit by minimizing the value of quantum cost and garbage outputs of it. In this paper, we presented two ways for partial products generation with reversible gates. We propose a new design of reversible 12X12 reversible Wallace tree multiplier for single precision and double precision mantissa multiplier circuit. Also 5X5 and 5X12 reversible Wallace tree multiplier for double precision multiplier. Here we use the optimized designs of reversible half adder, Full adder and 4:2 compressors. In the final summation stage, we carefully shifted the product terms and add them. For this stage we have carefully chosen the adders and compressor in such way to get the optimized results in terms of quantum cost and Garbage output. We have also shown the improvement in single precision floating point multiplier in terms of Quantum cost and Garbage output.