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Priori Information Hidden in Error Code Redundant Information

IP.com Disclosure Number: IPCOM000115569D
Original Publication Date: 1995-May-01
Included in the Prior Art Database: 2005-Mar-30
Document File: 2 page(s) / 86K

Publishing Venue

IBM

Related People

Ouchi, NK: AUTHOR

Abstract

Disclosed is a mechanism that initializes the error code generating hardware with the priori information for initial transmission of the record and also on receipt of the record. The a priori information is thus checked as part of the error code information. Added information space, hardware, or checking steps are avoided.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 52% of the total text.

Priori Information Hidden in Error Code Redundant Information

      Disclosed is a mechanism that initializes the error code
generating hardware with the priori information for initial
transmission of the record and also on receipt of the record.  The a
priori information is thus checked as part of the error code
information.  Added information space, hardware, or checking steps
are avoided.

      In many storage systems, it is desirable to check that the
information received is the requested information.  In DASD devices,
the physical address of the DASD track is carried with every record
on the track to guard against selecting the wrong track.  These
require added bytes on the track and added checking steps.  The
physical address is a priori information.  That is, this was known
before the transfer, and the check is just to insure that the correct
track was selected.  Most storage systems use error detection and/or
correction codes for error control.

      Disclosed is a mechanism that initializes the error code
generating hardware with the a priori information for initial
transmission of the record and also on receipt of the record.  The a
priori information is thus checked as part of the error code
information.  Added information space, hardware, or checking steps
are avoided.

      Most error code generation hardware requires that the initial
state be set in the generator.  This must be done for transmission,
writing and for receipt, reading.  The data is then processed through
the generator to create the error control bytes.  These are
transmitted as part of the data and are checked upon receipt.  The
initial state is usually an arbitrary pattern, all ones for example,
and is known by the transmitter and receiver.  This is a priori
information.  Disclosed is the setting of the error code generation
hardware to useful a priori information such as track address to
generate the redundant error control information and also for
checking the received data.  The check will insure not only the data
but that it was the expected record.

      A simple example where a data record is written and then read
from DASD follows.  The track is known and is set as the initial
condition of the error correction c...