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Storage Intermittent Test

IP.com Disclosure Number: IPCOM000079506D
Original Publication Date: 1973-Jul-01
Included in the Prior Art Database: 2005-Feb-26
Document File: 2 page(s) / 13K

Publishing Venue

IBM

Related People

Sitler, WR: AUTHOR

Abstract

In large-scale integrated storage units, failure detection and correction is a major area of concern.

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This is the abbreviated version, containing approximately 55% of the total text.

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Storage Intermittent Test

In large-scale integrated storage units, failure detection and correction is a major area of concern.

The test process described below detects and locates solid single and double-cell failures, and intermittent failing cells.

Both main store and control store are included in the test process. The process is based upon the following ground rules. A) All single-cell failures in control store will be replaced.

B) A cell involved in a double failure in main storage will be

swapped.

C) Any cell that fails intermittently or does not fail

solidly will be replaced.

The process is in three parts which perform the following functions:

Part I. determines the storage size and allows for a control storage size of 64K bytes. Storage is then validated by storing 0's into it. Any errors that occur during this time are ignored and when all of storage is validated, part B is loaded into control store.

Part II. is loaded into the lower half of control store and will test the upper half of control store. The upper half of control store is loaded with all 1's and the storage data bus output check is interrogated. If a storage data bus out (SDBO) check is detected during the store operation, a message is printed out for the operator's attention.

If no SDBO check is detected during the store operation, the first word in the upper half of control store is read and SDBO check is interrogated. If no SDBO check is found, the double-error indication is tested followed by normal error- detection checks. If these indicators are off, a counter is checked to determine if the test has read the word N times. If not equal to N, one is added to the counter and the word is read. The error indicators are checked until the counter equals
N. When this occurs, the data is changed at th...