| 摘要 |
PROBLEM TO BE SOLVED: To provide a digital signal system to determine approximate values of logarithm x with a base b. SOLUTION: This system is provided with a circuit 32 to memorize x in digital expression, a circuit to identify the most significant digit (MSD) of the digital expression, a table 36 to store a prescribed set of logarithms having b as the base, a circuit to designate addresses in the table, and output a predetermined single logarithm corresponding to a first number (I<SB>a</SB>) among the set of the numbers, and a circuit 38 for outputting an approximate value of the logarithm of the value x corresponding to one of predetermined logarithms, and in response to an estimation function between the logarithms at a first and a second endpoints. The estimation function estimates the corresponding logarithm based on a bit group expressing distance from the endpoint. COPYRIGHT: (C)2004,JPO
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