Browse Prior Art Database

Asynchronous Performance of I O Terminating Instructions

IP.com Disclosure Number: IPCOM000088499D
Original Publication Date: 1977-Jun-01
Included in the Prior Art Database: 2005-Mar-04
Document File: 1 page(s) / 11K

Publishing Venue

IBM

Related People

Dugan, RJ: AUTHOR [+2]

Abstract

Instructions for terminating input/output (I/O) operations (such as Halt I/O, Halt Device, etc.) notably require a degree of synchronism between the central processor and I/O channel which could impair the performance of both. This can be avoided by adapting the I/O channel to carry out the operations required to effectuate termination asynchronously relative to the central processor and to notify the central processor of the conclusion of the latter operation by means of an I/O interruption (i.e., subject to asynchronous acceptance by the central processor).

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Asynchronous Performance of I O Terminating Instructions

Instructions for terminating input/output (I/O) operations (such as Halt I/O, Halt Device, etc.) notably require a degree of synchronism between the central processor and I/O channel which could impair the performance of both. This can be avoided by adapting the I/O channel to carry out the operations required to effectuate termination asynchronously relative to the central processor and to notify the central processor of the conclusion of the latter operation by means of an I/O interruption (i.e., subject to asynchronous acceptance by the central processor).

Preferably, the adapted channel should be capable of "waiting out" temporary busy conditions whether signalled by a control unit or device without having to report status to the central processor.

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