Browse Prior Art Database

Diagnostic Wrap Using Cyclic Redundancy Checking

IP.com Disclosure Number: IPCOM000088868D
Original Publication Date: 1977-Aug-01
Included in the Prior Art Database: 2005-Mar-04
Document File: 1 page(s) / 11K

Publishing Venue

IBM

Related People

Elliot, JC: AUTHOR

Abstract

Verification of data path and control circuit integrity in half duplex systems is achieved with a minimum of additional circuits or duplication of data paths through the use of a cyclic redundancy checking (CRC) diagnostic wrap technique.

This text was extracted from a PDF file.
This is the abbreviated version, containing approximately 100% of the total text.

Page 1 of 1

Diagnostic Wrap Using Cyclic Redundancy Checking

Verification of data path and control circuit integrity in half duplex systems is achieved with a minimum of additional circuits or duplication of data paths through the use of a cyclic redundancy checking (CRC) diagnostic wrap technique.

The diagnostic source 1 provides the test data with precalculated CRC. The data + CRC is transferred through the intermediate buffering 2, the serializer 3, driver 4 and back through the receiver 5 and deserializer 6 to the CRC generator/checker 7. The generation of CRC on transmitted data is inhibited while the generation of CRC on incoming data is enabled. Since the wrapped data has precalculated CRC, the CRC generation should indicate zero residue (assumes initial value of CRC = all zeros) if the integrity of the data is good. Good or bad CRC indication then becomes the indicator or status response to the diagnostic source.

The advantage of this technique is that diagnostic checking in half duplex systems does not require duplicate data paths or complex control or timing. The checking circuits are in hardware and are part of the normal data path. The checking circuits function in the same manner as for a routine data transfer. CRC checking provides a high level of reliability. Engine utilization is reduced.

1