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. 04, 1989
Filed:
Dec. 15, 1986
Lothar Krings, Baden, CH;
BBC Brown, Boveri & Company, Limited, Baden, CH;
Abstract
When a fault is detected in a processor, program execution in this processor is interrupted and taken up again by a standby processor from an earlier uncorrupted state, a recovery point. Such recovery points are specially provided in the program. A save copy of the state at the recovery points is created in each case in a state save unit by recording changes compared with the respective previous state. The data memory existing in the state save unit has pairs of memory words, in which arrangement the state at the recovery point last reached is in each case saved in one of the memory words and the current changes are in each case recorded in the respective other memory word. The memory words are accessed via pointers which are formed by a control logic from two check bits allocated to each memory word pair. Processing of the check bits and of the pointers is very fast. It is not necessary to copy data within the state save unit. The standby processor has direct access to the saved data.