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Cyclic Redundancy Check Generator Having Field Replaceable Unit Isolation

IP.com Disclosure Number: IPCOM000103120D
Original Publication Date: 1990-Jun-01
Included in the Prior Art Database: 2005-Mar-17
Document File: 1 page(s) / 37K

Publishing Venue

IBM

Related People

Chapman, RJ: AUTHOR

Abstract

Cyclic redundancy check (CRC) logic is used for error checking, but frequently has little field-replaceable unit (FRU) isolation. CRC error checking is accomplished by scanning data through a CRC checker upon its receipt and comparing the results with that created by a CRC generator at the point of origin. If the CRC checker is located on a different FRU than the CRC generator, the source of a detected error cannot easily be attributed to a particular FRU. The problem thus presented is how to more precisely locate the source of an error.

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Cyclic Redundancy Check Generator Having Field Replaceable Unit Isolation

      Cyclic redundancy check (CRC) logic is used for error checking,
but frequently has little field-replaceable unit (FRU) isolation.
CRC error checking is accomplished by scanning data through a CRC
checker upon its receipt and comparing the results with that created
by a CRC generator at the point of origin.  If the CRC checker is
located on a different FRU than the CRC generator, the source of a
detected error cannot easily be attributed to a particular FRU.  The
problem thus presented is how to more precisely locate the source of
an error.

      The aforementioned problem is solved by a logic design with
permits the CRC generator to check itself each time it is used.  This
is achieved by routing the generated CRC back through the buffer and
CRC generator itself, as shown in the figure.  A multiplexer is used
to control which data is fed into the buffer.  If the CRC generator
does not in the end have the proper output, the CRC generator or
buffer is not functioning properly and its FRU requires replacement.
The proper output will have all zeros or all ones, depending upon the
particular CRC design.

      Disclosed anonymously.