The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Feb. 05, 2002
Filed:
Jan. 19, 1999
Applicant:
Inventors:
Fumiaki Nagao, Gifu, JP;
Masato Fuma, Ichinomiya, JP;
Assignee:
Sanyo Electric Co., Ltd., , JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G06F 7/556 ;
U.S. Cl.
CPC ...
G06F 7/556 ;
Abstract
Logarithm of data x being input is taken to calculate a decibel value y. The input value x is separated into mantissa value a and exponent value b by a separator or on the basis of an expression x=a·2 . Logarithmic value 10·log a corresponding to the mantissa value a is read from ROM. The exponent value b is multiplied with a constant 10·log 2 for logarithm of 2 by a multiplier. A logarithmic value of the value a read from the ROM is added to b·10·log 2 output from the multiplier by an adder to obtain the decibel value y. Thus, a simple circuit can compute the decibel value at a high speed.