Design of an Accurate, Cost-effective Radix-4 Booth Multiplier

Multiplication is a key process in various applications. Consequently, the multiplier is a principal component in several hardware platforms. For multiplication of signed integers, radix-4 booth multipliers are widely used as they reduce the number of partial products to half. Several approximate multipliers for radix-4 booth multiplication have been presented in recent times to achieve energy efficiency. However, the errors displayed by these multipliers make them unsuitable for lossless applications. For these applications, accurate radix-4 booth multiplication is much needed. In this paper, we introduce an optimized algorithm and multiplier for accurate radix-4 booth multiplication. The algorithm reduces the number of bits that participate in the addition process during multiplication. At the same time, the algorithm has sufficient storage area for reduced design complexity in its multiplier. The multiplier gives promising results of 100% when tested for accuracy for a wide spectrum and all possible cases of multiplicand-multiplier pairs. Besides, the multiplier is shown to be cost-effective. Lastly, we compare our multiplier with the current radix-4 booth multipliers in terms of key error parameters to highlight its accuracy.