LOW-LATENCY ARC-TANGENT CALCULATION STRUCTURE AND CALCULATION METHOD THEREOF

Abstract

The present invention provides a low-latency arc-tangent calculation structure and a calculation method thereof. The arc-tangent calculation structure comprises two lookup tables, a subtractor, a sign comparator, a numerical comparator and a shift encoder. The present invention divides the coordinate system into a plurality of sectors for simplifying the lookup tables. The first lookup table is used to perform logarithmic transformation so as to replace a divider with a subtractor. The second lookup table integrates an exponentiation table and an angle table to translate the output of the subtractor into arc-tangent value θ. Then, θ is shifted to a correct angle according to the output of the shift encoder.