Dismiss
InnovationQ will be updated on Sunday, Oct. 22, from 10am ET - noon. You may experience brief service interruptions during that time.
Browse Prior Art Database

Technique to Improve Field Replaceable Unit Isolation for Large Systems

IP.com Disclosure Number: IPCOM000060900D
Original Publication Date: 1986-May-01
Included in the Prior Art Database: 2005-Mar-09
Document File: 2 page(s) / 34K

Publishing Venue

IBM

Related People

Messina, BU: AUTHOR [+2]

Abstract

This hardware checking technique reduces the number of field replaceable units (FRUs) implicated when an error occurs. As shown in the figure, error signals S1,S2,...,Sn are generated on FRU A, and latched up on FRU B in latches C1,C2,...,Cn, respectively. Also Y, the logical OR of signals S1,S2,...,Sn is generated on FRU A and sent to FRU B where it is latched in latch R. Two error syndromes can then be used to determine the FRU or FRUs in error. Syndrome 1 If any latch Ci is on and R is on, then FRU A is an error. Syndrome 2 If any latch Ci is on and R if off, or R is on but the Ci's are off, then FRU B and the board containing FRU A and Bcan also be in error.

This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 100% of the total text.

Page 1 of 2

Technique to Improve Field Replaceable Unit Isolation for Large Systems

This hardware checking technique reduces the number of field replaceable units (FRUs) implicated when an error occurs. As shown in the figure, error signals S1,S2,...,Sn are generated on FRU A, and latched up on FRU B in latches C1,C2,...,Cn, respectively. Also Y, the logical OR of signals S1,S2,...,Sn is generated on FRU A and sent to FRU B where it is latched in latch R. Two error syndromes can then be used to determine the FRU or FRUs in error. Syndrome 1 If any latch Ci is on and R is on, then FRU A is an error. Syndrome 2 If any latch Ci is on and R if off, or R is on but the Ci's are off, then FRU B and the board containing FRU A and Bcan also be in error. It can be seen, that syndrome 1 uniquely implicates FRU Awhile syndrome 2 indicates that a failure has occurred somewhere in FRUA, FRUB or the board containing those FRUs.

1

Page 2 of 2

2

[This page contains 3 pictures or other non-text objects]