Browse Prior Art Database

Enhanced Error Reporting Mechanism

IP.com Disclosure Number: IPCOM000108476D
Original Publication Date: 1992-Jun-01
Included in the Prior Art Database: 2005-Mar-22
Document File: 2 page(s) / 56K

Publishing Venue

IBM

Related People

Bailey, WD: AUTHOR [+2]

Abstract

Disclosed is a method which can be used to report unexpected events across a communications bus. Unlike other currently used methods, this method uses only existing data and control signals while providing multiple bits of information describing the event. Yet, the event reporting is independent of the normal data flow and can thus occur asynchronously with respect to the normal data flow. In addition, this method requires no microcode involvement to generate event information, so it is faster than a microcode generated message.

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This is the abbreviated version, containing approximately 69% of the total text.

Enhanced Error Reporting Mechanism

       Disclosed is a method which can be used to report
unexpected events across a communications bus.  Unlike other
currently used methods, this method uses only existing data and
control signals while providing multiple bits of information
describing the event.  Yet, the event reporting is independent of the
normal data flow and can thus occur asynchronously with respect to
the normal data flow.  In addition, this method requires no microcode
involvement to generate event information, so it is faster than a
microcode generated message.

      The implementation of this method involves two logical entities
connected by a communications bus, as depicted in the figure.  Block
A exchanges data and receives status information from block B.
Internal logic in block B can detect an error or other asynchronous
interface event.  When any event has been detected, an Event Present
signal is produced.  This signal is forwarded to an arbitrator in
block B that activates a bid for use of the bus.  This bid is not
accepted if the bus is currently in use.  As soon as the bus enters
an idle state, further transfers involving the normal data flow are
temporarily stopped.  Then, the address used in reporting the event
is generated and the data corresponding to the event is sent to block
A.  The event message indicates the failing area as seen by block B
and the reason for the failure.  Once the event is reported, normal
data flow is all...