INVERSE TANGENT ARITHMETIC CIRCUIT IN DIGITAL SIGNAL PROCESSING

摘要

PROBLEM TO BE SOLVED: To provide an inverse tangent arithmetic circuit capable of reducing the arithmetic processing amount and decreasing the capacity of the ROM table.;SOLUTION: A phase range reduction part 31 obtains the magnitudes |X|, |Y| of input signals X, Y, shifts bits of the magnitudes |X|, |Y| which is grater so as to obtain a maximum value within an input dynamic range of an inverse tangent function ROM 32 and shifts bits of the magnitudes |X|, |Y| which is smaller by the same amount of bit shift as that of the greater magnitude so as to normalize the result. Thus, the arithmetic amount of the phase range reduction part 31 is reduced and the capacity of an arithmetic table of the inverse tangent function ROM 32 is decreased.;COPYRIGHT: (C)2003,JPO