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:
Jul. 04, 1978
Filed:
Jan. 28, 1977
Barry R Borgerson, Gwynedd Valley, PA (US);
Garold S Tjaden, Doylestown, PA (US);
Sperry Rand Corporation, New York, NY (US);
Abstract
The one's complement subtractive arithmetic unit comprises a parallel adder with a connection for providing an end-around carry, from the carry output of the most significant stage to the carry input of the least significant stage. The parallel adder is implemented utilizing multiple bit LSI ALU chips or microprocessor slices that provide group propagate and generate indication signals. Carry look-ahead chips responsive to the group propagate and generate indication signals provide a fast carry arrangement for the arithmetic unit. Circuitry is included to detect when all of the carry propagate indicators are on for providing a signal to the carry input of the parallel adder resulting in the equivalent performance of a one's complement subtractive arithmetic unit.