Browse Prior Art Database

Component Identification Data Retrieval Via Serial Interface

IP.com Disclosure Number: IPCOM000038199D
Original Publication Date: 1989-Dec-01
Included in the Prior Art Database: 2005-Jan-31
Document File: 1 page(s) / 12K

Publishing Venue

IBM

Related People

Marquart, DW: AUTHOR

Abstract

Described is a technique where component identification data of a machine are accessed through a pre-existing interface. Cards or other units may have identification data in non-volatile storage on the unit. This identification data must be reported to the system service processor. The number of signal lines that are required at the card boundary make this a difficult and costly requirement. The interface must not take a large number of pins (wires, signals) since the connection between the processor and the service processor is through a set of connectors that has a limited number of pins. By providing access to the data through a pre-existing interface, the number of I/O pins required is minimized.

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Component Identification Data Retrieval Via Serial Interface

Described is a technique where component identification data of a machine are accessed through a pre-existing interface. Cards or other units may have identification data in non-volatile storage on the unit. This identification data must be reported to the system service processor. The number of signal lines that are required at the card boundary make this a difficult and costly requirement. The interface must not take a large number of pins (wires, signals) since the connection between the processor and the service processor is through a set of connectors that has a limited number of pins. By providing access to the data through a pre-existing interface, the number of I/O pins required is minimized.

Many logic units use LSSD for testing, and many logic units have their LSSD interface connected to a service processor for testing and problem diagnosis. Therefore, LSSD is one possible interface through which the component identification data are accessed.

The logic unit must have a set of logic controlled by the LSSD scan interface that connects to the data store. This logic reads the data store into LSSD scan latches, and the service processor then scans the data out. The logic that does the read is set up by the service processor scanning the proper starting state into the logic, then the starting system clocks to the logic so that the logic is permitted to perform its function and read the data.

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