Browse Prior Art Database

Self-Monitoring Fault-Tolerant Logic Redundancy Structure

IP.com Disclosure Number: IPCOM000101716D
Original Publication Date: 1990-Aug-01
Included in the Prior Art Database: 2005-Mar-16
Document File: 3 page(s) / 79K

Publishing Venue

IBM

Related People

Aichelmann, FJ, Jr: AUTHOR

Abstract

A method is proposed for providing a logic redundancy structure which can operate with either simplex or duplex input signals that is self- monitoring. Additionally, this structure eliminates the need for an external selection or switching mechanism (i.e., maintenance facility).

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 72% of the total text.

Self-Monitoring Fault-Tolerant Logic Redundancy Structure

       A method is proposed for providing a logic redundancy
structure which can operate with either simplex or duplex input
signals that is self- monitoring.  Additionally, this structure
eliminates the need for an external selection or switching mechanism
(i.e., maintenance facility).

      Conventional logic redundancy structures that select between
two paths require external signals which monitor the results from the
two paths and result in selecting one as a master and the other as a
slave.  This type of monitoring and selection requires an external
maintenance facility which requires extensive interfacing for on-line
operations. Fig. 1 depicts a block diagram of the typical or
conventional logic redundancy structure.  Fig. 2 describes a
self-monitoring-type logic redundancy configuration for either
simplex or duplex inputs which does not require the intervention of a
maintenance facility.  Fig. 3 ex- pands the diagram of Fig. 2 to
separate the redundant logic from the self-monitoring selection
mechanism.

      The self-monitoring structure uses changes in the output from
the combinational logic during an IPL or power-on-reset time to
verify that stuck faults do not inhibit proper operations.  Fig. 4
shows the logical embodiment of the self-monitoring structure.
During IPL or power- on-reset time the network inputs are toggled.
These inputs pro- duce corresponding output changes through the
c...