Patent ID: 7334200

Claim:
A method for fixed-width modified Booth multiplication, comprising: generating partial products for a W-bit multiplier encoded using modified Booth coding and a multiplicand; and accumulating the partial products to form a W-bit product, wherein said accumulating step comprises dividing truncated bits into two groups, LP MAJOR and LP MINOR , wherein LP is least significant product, generating an approximate carry value using the bits of LP MINOR with a circuit that produces a pre-selected number (N AC ) of approximate carry signals (a_carry_ 0 , a_carry_ 1 , . . . , a_carry_N AC-1 ), wherein an approximate carry signal (a_carry_i) has a value of 1 if at least “2i+1” of a plurality of coded values y″ w/2-2 , y″ w/2-3 , . . . , y″ 1 and y″ 0 have a value of 1, and generating an exact carry value for LP MAJOR using the approximate carry value and the bits of LP MAJOR .