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:
Feb. 27, 1979
Filed:
May. 20, 1977
Richard L Bishop, Sunnyvale, CA (US);
William A Gibson, Cupertino, CA (US);
Amdahl Corporation, Sunnyvale, CA (US);
Abstract
A data processing system having a principal apparatus, such as a programmable large-scale data processing system, and a secondary apparatus. The secondary apparatus performs fault detection and analysis on the principal apparatus. The secondary apparatus under control of a secondary program and independently from the principal apparatus, accesses information from different points, such as latch circuits, throughout the principal appartus. The accessed information is utilized by the secondary apparatus to form an actual checksum having a value determined by the accessed information. The actual checksum thus formed is compared with an expected checksum provided from storage by the secondary apparatus. If the actual and expected checksums are different, a fault condition is indicated. An analysis of selected subsets of points in the primary apparatus is made using a compacted scan composed of the values of the selected subset of points.