Design and Comparison of Regularize Modified Booth Multiplier Using Different Adders

The conventional Modified Booth Encoding (MBE) generates n/2+1 rows instead of n/2 rows and also irregular partial product (PP) array because of the extra neg (sign bit) bit at the lower significant bit (LSB) position of each partial product row. In this, a simple approach has been proposed to generate n/2 partial product rows along with regular partial product arrays, thereby reducing the area and power of MBE multipliers [2]. Here technique to find direct 2's complement has been added to last partial product row in order to reduce partial product rows to n/2. Partial products have been regularized by adding LSB of the partial product row with neg bit. Along with this to generate final result different adders have been used and compared. Ripple carry adder, carry lookahed adder and carry select adder have been used in third and final step. Carry select adder shown significant improvement in delay compared to carry lookahed adder and ripple carry adder.