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Battery Backup Failure Detection

IP.com Disclosure Number: IPCOM000047389D
Original Publication Date: 1983-Nov-01
Included in the Prior Art Database: 2005-Feb-07
Document File: 2 page(s) / 35K

Publishing Venue

IBM

Related People

Desautels, JC: AUTHOR [+2]

Abstract

In any functional unit, normally mains powered but equipped with a battery for maintaining data integrity during power failure for at least key areas that are volatile, a mechanism can be provided that will provide an adequate test of the effectiveness of the battery operation during power down without the use of a conventional capacitor system. The mechanism comprises a dedicated data storage area, capable of being selectively read and written when power is up, forming part of the data storage areas protected by the battery and of the same nature. This dedicated area is loaded, when power is up, with predetermined data and is tested, after each power down, to determine whether or not it still holds the predetermined data. While not theoretically conclusive, the mechanism provides an adequate and practical test.

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Battery Backup Failure Detection

In any functional unit, normally mains powered but equipped with a battery for maintaining data integrity during power failure for at least key areas that are volatile, a mechanism can be provided that will provide an adequate test of the effectiveness of the battery operation during power down without the use of a conventional capacitor system. The mechanism comprises a dedicated data storage area, capable of being selectively read and written when power is up, forming part of the data storage areas protected by the battery and of the same nature. This dedicated area is loaded, when power is up, with predetermined data and is tested, after each power down, to determine whether or not it still holds the predetermined data. While not theoretically conclusive, the mechanism provides an adequate and practical test. The assumption is that, if the data in the dedicated area changes, the remaining battery protected data will also have changed and restoration is required. For example, the time-of-day clock in a processor, which resides in a dedicated location in storage, is protected by a battery along with at least one other location in storage which can be considered a "continuity register". At the very first power on this "continuity register" is set to a predetermined value. Thereafter, every time the system is powered on, the stored value is compared to the predetermined value. If the comparison result is a mixture of ones and zeros...