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. 09, 1985
Filed:
Jul. 13, 1982
Peter B Criswell, Bethel, MN (US);
Sperry Corporation, New York, NY (US);
Abstract
A method and a means are disclosed for the throughchecking of the normalizer operations of an arithmetic unit of a data processing system involving both integer and floating-point formats in single and double precision operations. A post normalizer is used in conjunction with the main normalizer of the arithmetic unit to determine if the result is indeed normalized. Where the post normalize count is zero, an error designator remains inactivated. However, where the count is non-zero, the error designator is activated to indicate an error exists, unless it is disabled by separate circuitry which detects that the number being shifted is .+-..0.. The preferred embodiment disclosed herein checks the operation of a pair of 72-bit main normalizers with a single 13-bit post normalizer. A plurality of instructions in which this check is significant are illustrated.