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:
Jan. 28, 1992
Filed:
Nov. 07, 1989
Fuyuki Okamoto, Tokyo, JP;
NEC Corporation, Tokyo, JP;
Abstract
In an absolute value subtraction processing of .vertline.X-Y.vertline., carry generation and propagation functions and group carry generation and propagation functions are first generated. Then, a carry is calculated at the most significant bit in the summation of a first operand and a complement of '2' of a second operand by use of the above functions. Where the carry is '1', the above summation remains continued. Where the carry is zero, additional first and second functions are generated by inverting logic ORs of the carry generation and propagation functions and of the group carry generation and propagation functions. Thus, the summation of the second operand and a complement of '2' of the first operand is realized by use of the additional functions, the carry propagation function, and the group carry propagation function.