Patent ID: 8356066

Claim:
A method of generating a fixed point approximation of an inverse function used by an electronic device, comprising: determining a first value, denoted N, representing a position of the most significant bit in x and storing the first value in a computer readable storage; forming an index, denoted M, from the k o bits immediately following the most significant bit, wherein M is used as an index to address a table that contains a plurality of second values, each of the second values representing a sum of one and a binary fraction representation of M, and storing the particular second value within the computer readable storage, the particular second value being denoted v 2 , corresponding to the index; creating a fixed-point number from remaining bits of x if any exist that directly follow the index M; inserting the remaining bits into the created number starting at the k o +1 fractional-bit to get an intermediate result, wherein both the integer-bits and the first k o fractional-bits of the created number are all zero, and wherein the remaining bits of the intermediate result are the remaining bits of x to generate a third value, and storing the third value, denoted v 4 , within the computer readable storage; computing a final result by a data processor using fixed-point arithmetic to generate said fixed point approximation of said inverse function, wherein computing the final result comprises computing a first result by subtracting a product of the second and third values from one, computing a second result by multiplying the first result by the second value, and computing the final result by multiplying the second result by the first value.