Patent ID: 6910059

Claim:
An apparatus for calculating an exponential calculating result for a base 2 floating-point number wherein the floating-point number is represented in the format of (−1) Sx ·2 Ex ·m x and the exponential calculating result Y is represented in the format of (−1) Sy ·2 Ey ·m y , where S x is a sign of the floating-point number, S y is a sign of the exponential calculating result, E x is an exponent of the floating-point number, E y is an exponent of the exponential calculating result, m x is a mantissa of the floating-point number, m y is a mantissa of the exponential calculating result, 1≦m x <2 and 1≦m y <2, the apparatus comprising: a transforming device for receiving the sign of a floating-point number, the exponent of the floating-point number and the mantissa of the floating-point number, transforming the floating-point number to an integer part and a fractional part, and outputting the integer part and the fractional part, wherein the fractional part is an N-bit number and divided into K parts which have N 1 , N 2 , . . . , N K bits respectively, wherein N=N 1 +N 2 + . . . +N K ; K exponential tables, each of the exponential tables for receiving one of the K parts divided from the fractional part and outputting a result; and a multiplier for receiving all results from the exponential tables and outputting the mantissa of the exponential calculating result; wherein the integer part outputted from the transforming device is the exponent of the exponential calculating result, the sign of the exponential calculating result is 0 and the N, K, N 1 , N 2 , . . . , N K are natural numbers.