Browse Prior Art Database

Fault Tolerant Dataflow System Employing Two Dimensional Parity

IP.com Disclosure Number: IPCOM000118338D
Original Publication Date: 1996-Dec-01
Included in the Prior Art Database: 2005-Apr-01
Document File: 2 page(s) / 69K

Publishing Venue

IBM

Related People

Balasubramian, V: AUTHOR [+3]

Abstract

Disclosed is a technique which provides fault tolerance in a dataflow system with no data manipulation between the input ports and output ports. All single-bit errors are corrected online with no impact to system thruput or latency. This allows the system to remain functional in the presence of faults, increasing the availability.

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Fault Tolerant Dataflow System Employing Two Dimensional Parity

      Disclosed is a technique which provides fault tolerance in a
dataflow system with no data manipulation between the input ports and
output ports.  All single-bit errors are corrected online with no
impact to system thruput or latency.  This allows the system to
remain functional in the presence of faults, increasing the
availability.

      This system is, essentially, a distance-3 systematic code on
the input data.  The check bits consist of two sets of parities
operating on orthogonal data sets, as shown in Fig. 1.  Any single
data bit error will affect exactly one parity bit from each set and
can be accurately located and corrected on-line.  The slice parities
are allowed to flow through a separate logic block in order to
eliminate duplicate error indications during the parity checking
phase.  Note that  Fig. 1 relates to a design with eight slices,
where each slice has exactly one bit from every byte.  The
two-dimensional parity scheme is  equally applicable to designs with
more or less than eight slices, as long as the input data
distribution is such that no slice has more than  one bit from any
byte.

      Slice Generation and Data Correction

      The input data word is bit sliced so that each of eight data
flow logic groups receives exactly one bit from every input byte.
The input parities flow through a separate logic group.  The received
data is exclusive or'd togethe...