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:
Dec. 08, 1998
Filed:
Sep. 10, 1996
Matsushita Electric Industrial Co., Ltd., Osaka, JP;
Abstract
In an IDCT circuit, a first RAC and a second RAC each have a ROM for sequentially generating a plurality of partial products and an accumulator for performing a digit-adjustment accumulation of the generated partial products while truncating the LSB of an intermediate accumulation result for every cycle. The first RAC further has a carry bit generator for holding a carry bit of one cycle before and for generating a carry bit of a current cycle by performing a majority arithmetic operation of the LSB of an intermediate accumulation result of the first RAC, the LSB of an intermediate accumulation result of the second RAC and the one-cycle-before carry bit. The second RAC further has a borrow bit generator for holding a borrow bit of one cycle before and for generating a borrow bit of a current cycle by performing a majority arithmetic operation of the LSB of an intermediate accumulation result of the first RAC, an inverted bit of the LSB of an intermediate accumulation result of the second RAC and the one-cycle-before borrow bit. A final accumulation result of the first RAC, a final accumulation result of the second RAC, a final carry bit and a final borrow bit are used in butterfly arithmetic operations.