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:
Sep. 28, 1993
Filed:
Nov. 26, 1990
Michael Catherwood, Austin, TX (US);
Greg Viot, Austin, TX (US);
James L Broseghini, Austin, TX (US);
Motorola, Inc., Schaumburg, IL (US);
Abstract
A digital data processor is capable of performing limited modulo arithmetic. The base, M, of the modulo arithmetic to be preformed by the processor must be equal to 2.sup.X, where X is an integer. The method and apparatus is particularly useful for generating addresses for a circular buffer or queue data structure and avoids both the large amount of hardware required for general modulo arithmetic and the software overhead associated with the use of linear arithmetic to generate modulo addresses. According to this method, X is represented as a first digital value. This representation of X is ANDed with a second digital data value (an offset). The result is then ADDed linearly with a third digital data value (a current address with the buffer). During this addition process, certain carry-out signals are inhibited from propagating, according to the digital representation of X.