TRANSCENDENTAL FUNCTION APPROXIMATION APPARATUS AND METHOD

摘要

TRANSCENDENTAL FUNCTION APPROXIMATION APPARATUS AND METHOD Transcendental function approximation using a regional approximation look-up table, offset lookup table, scaling shifter and interpolation adder/subtractor. Rapid fixed-point arithmetic calculations can be accomplished which approximate values of transcendental functions to a predetermined accuracy. The invention accepts an N bit argument and produces an N bit result allowing the placement of the radix point in the two numbers to be different. Different parts of the input argument are fed in parallel to the regional approximation look-up table and the offset lookup table. A scaling shifter converts the output of the offset lookup table and regional lookup table to a result usable by the interpolation adder/subtractor processor. The regional approximation lookup table also provides information to the interpolation processor which provides the N bit approximation.