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Method for Testing Interruptions

IP.com Disclosure Number: IPCOM000080588D
Original Publication Date: 1974-Jan-01
Included in the Prior Art Database: 2005-Feb-27
Document File: 2 page(s) / 39K

Publishing Venue

IBM

Related People

Price, R: AUTHOR

Abstract

This method makes use of the noncommutativity of certain sequences of arithmetic operations, to verify that the required interruptions arrive in the correct order when provoked.

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Method for Testing Interruptions

This method makes use of the noncommutativity of certain sequences of arithmetic operations, to verify that the required interruptions arrive in the correct order when provoked.

In some process control systems, the computers run 24 hours a day every day, yet the correct running of the computer must be verified as completely as possible without interfering with the process. In particular, because the computers are interruption driven, the interruption structure must be tested, by provoking interruptions and testing their correct arrival, but without significantly interfering with the interruptions which arrive due to the process controlled.

According to the proposed method, the test interruptions are provoked two at a time, and the test must verify that both arrive and in the correct order. The test interruptions are handled by simple routines, one routine per interruption level. In each of the interruption routines, is inserted a simple arithmetic operation on a register available to all of the routines and to the test program itself. The arithmetic operations and the initial value of the register are chosen so that, for each pair or group of interruptions tested, the correct value can only be obtained if the required operations and no others are performed in the correct order. As an example, the following table gives the list of the operations chosen for a 2750 voice and data switching system with 12 interruption levels.

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