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:
Aug. 31, 1999
Filed:
Nov. 13, 1997
Juergen Haas, Kusterdingen, DE;
Wilhelm Haller, Remshalden, DE;
Ulrich Krauch, Dettenhausen, DE;
Thomas Ludwig, Sindelfingen, DE;
Holger Wetter, Boeblingen, DE;
International Business Machines Corporation, Armonk, NY (US);
Abstract
A combined adder and logic unit having a reduced operation delay of arithmetic and logic operations, and providing an improved fan in and reduced wiring delays and capacity if implemented in the arithmetic and logic section of a microprocessor chip. The unit comprises a carry network (30) connected to operand inputs for generating carry-out signals of the byte positions (By0-By7) and further comprises a pre-sum logic (32) having a bit function generator (42) and a sum generator (45, 46, 48). Said bit function generator derives from the operands Ai and Bi bit functions Gi, Pi which are provided as logic function output and as input to said sum generator for producing preliminary arithmetic functions (SUM0, SUM1) to anticipate carry-in signals of one or zero. A result selector (70) is controlled by a byte position carry-out signal (Cy55) from the carry network means and by operation control signals to select from the output of said pre-sum logic one of the arithmetic functions (SUM0, SUM1) or one of the logic functions as result of the unit operation.