Browse Prior Art Database

Method for a Serial Channel Extender to Support DATA Streaming DATA Transfer

IP.com Disclosure Number: IPCOM000035351D
Original Publication Date: 1989-Jul-01
Included in the Prior Art Database: 2005-Jan-28
Document File: 1 page(s) / 11K

Publishing Venue

IBM

Related People

Kubik, JJ: AUTHOR [+2]

Abstract

A system for communicating between a channel processor and a device controller processor over a path that includes a parallel bus and a serial link supports datastreaming data transfer as defined by the IBM OEMI Interface architecture. The serial channel extended uses the rising edge on one data transfer tag (SERVICE IN and DATA IN, or SERVICE OUT, DATA OUT, and COMMAND OUT) to drop the other data transfer tag. This procedure does not work for the last byte of data transferred since there will be no more tags to drop the tag currently active.

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Method for a Serial Channel Extender to Support DATA Streaming DATA Transfer

A system for communicating between a channel processor and a device controller processor over a path that includes a parallel bus and a serial link supports datastreaming data transfer as defined by the IBM OEMI Interface architecture. The serial channel extended uses the rising edge on one data transfer tag (SERVICE IN and DATA IN, or SERVICE OUT, DATA OUT, and COMMAND OUT) to drop the other data transfer tag. This procedure does not work for the last byte of data transferred since there will be no more tags to drop the tag currently active.

A timer exists in the portion of the serial link closest to the device controller processor which looks for the receipt of OUT tags associated with data transfer (SERVICE OUT, DATA OUT, or COMMAND OUT). If no OUT tags are received for a user-specified period of time, the circuit times-out. The OUT tag active when the circuit times-out will be dropped when the corresponding IN tag (SERVICE IN in the case of SERVICE OUT, DATA IN in the case of DATA OUT, and either IN tag in the case of COMMAND OUT) is dropped. The active OUT tag may also be dropped if a serial frame raising another OUT is received. This method allows for proper dropping of the last OUT tag associated with data transfer while at the same time providing for long pauses in a data transfer.

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