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"Device Address Switch Change Detection/Reporting"

IP.com Disclosure Number: IPCOM000037557D
Original Publication Date: 1989-Mar-01
Included in the Prior Art Database: 2005-Jan-29
Document File: 1 page(s) / 12K

Publishing Venue

IBM

Related People

Carlson, BA: AUTHOR [+2]

Abstract

By defining a standardized report and degate process for I/O devices detecting interface address changes during power-on periods, it is possible to prevent data integrity problems created by such changes as well as simplify the isolation of such changes.

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"Device Address Switch Change Detection/Reporting"

By defining a standardized report and degate process for I/O devices detecting interface address changes during power-on periods, it is possible to prevent data integrity problems created by such changes as well as simplify the isolation of such changes.

Devices attaching to systems via Intelligent Peripheral Interface-3 (IPI-3) must be assigned unique interface addresses. These addresses are assigned through the use of address switches attached to the rear panel of each device. In many cases, these address switches are easily accessible and can be changed during device power-on periods. Switch failures are also possible. Such changes/failures create data integrity problems and are normally difficult to isolate.

The isolation process is greatly simplified when devices implement the following detection and reporting sequence for address switch changes/failures: . Report the interface address switch change/failure to the system under its original address through the architected reporting means defined by IPI-3. . Degate (electrically disconnect) all drivers from the interface and do not respond to further commands sent across the interface. . By reporting the interface address switch change/ failure, a device-reported symptom that is assigned to a configured device is available to the system for analysis. This symptom is more meaningful than the series of errors that would normally occur.

Since the device is degate...