Patent ID: 7606850

Claim:
An apparatus for approximating a base-2 logarithm of a binary number, said apparatus comprising: a primary encoder for determining a position k within said binary number at which a “1” is first occurred; a shift register for assigning all bits to the right of said position k within said binary number as a fractional portion of a base-2 logarithm approximation of said binary number; a lookup table for utilizing a subset of said fractional portion to generate an adjustment value βm for said fractional portion; wherein said lookup table further includes means for utilizing said subset of said fractional portion to generate said adjustment value βm by β m = 1 2 ⁢ ⁢ log 2 ⁡ [ ( 1 + m M ) ⁢ ⁢ ( 1 + m + 1 M ) ] - m + 1 2 M where m is said subset of said fractional portion; and an adder for adding said fractional portion along with said adjustment value βm for said fractional portion to said k as a binary number representing an integer portion of said base-2 logarithm approximation of said binary number to form said base-2 logarithm approximation of said binary number.