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:
Apr. 24, 1990
Filed:
Mar. 11, 1988
Hedi Hmida, Paris, FR;
Pierre Duhamel, Issy Les Moulineaux, FR;
Abstract
A circuit for performing binary calculation, the circuit being of the type having at least one cell possessing: a first bit input (Ai), a second bit input (Bi), a carry-in input (Ri-1), circuitry (1600) for generating a two input bit exclusive-OR signal (Ai.sym.Bi) and its complement (Ai.sym.Bi), circuitry (1800) for producing a result signal, and circuitry (1900) for producing a carry-out signal (Ri), the circuitry being constituted by multiplexed logic. The complemented two input bit exclusive-OR signal (Ai.sym.Bi) is produced by inverting the two input bit exclusive-OR signal (Ai.sym.Bi), thereby making it possible to utilize only 15 transistors in the most cut-down version of the circuit. The invention also relates to a circuit (20) having an addition cell (22) calculating the sum of the input bits and a subtraction cell (24) calculating the difference of the input bits. The circuitry (1600) for producing the two input bit exclusive-OR signal (Ai.sym.Bi) and its complement (Ai.sym.Bi) are then used in common both by the addition cell (22) and by the subtraction cell (24).