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. 27, 1999
Filed:
Nov. 18, 1996
Roney S Wong, Sunnyvale, CA (US);
Shao-Kun Jiang, San Diego, CA (US);
Abstract
A fused floating point multiply-and-accumulate unit includes a multiplier which uses a modified Booth's algorithm to generate a sum and a carry representing a product of mantissas. An artifact of this algorithm is that the sum or carry may represent a negative value even though both mantissas are positive. The negative value may have a sign bit from sign extension or sign encoding of partial products in the multiplier. An artifact of the signed bit is a false carry out that results from canceling the sign bit. A 3-input adder simultaneously combines the sum and carry from the multiplier and performs the accumulation. The adder includes carry correction logic to suppress false carries and prevents a false carry from affecting more significant bits of the value being accumulated.