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:
May. 26, 1992
Filed:
Aug. 28, 1990
Eric H Persoon, Eindhoven, NL;
Christian J Vandenbulcke, Eindhoven, NL;
U.S. Philips Corporation, New York, NY (US);
Abstract
To generate quickly the several carry signals in a full adder circuit (for example a 40-bit circuit), the circuit is divided into a plurality of sub-circuits of a first type, in which complementary imaginary carry signals are generated parallel to each other. Carry look-ahead circuits are of a dual construction, each first carry look-ahead circuit receiving a logic '0' and each second carry look-ahead circuit receiving a login '1'. So the generated imaginary carry signals are complementary, from which the carry signal proper is selected with the aid of a multiplex switch. The multiplex switch is controlled by the carry signal generated in a preceding sub-circuit of the first type. Since a multiplex switch operates faster than 3-bit or 4-bit wide carry look-ahead circuits, which operate in parallel in groups, the carry signals are consequently generated faster.