Browse Prior Art Database

Internal Parity Checking And Regeneration for Mixed Parity/Non-Parity Data Sources

IP.com Disclosure Number: IPCOM000038041D
Original Publication Date: 1989-Oct-01
Included in the Prior Art Database: 2005-Jan-31
Document File: 1 page(s) / 11K

Publishing Venue

IBM

Related People

Bailey, RN: AUTHOR [+2]

Abstract

Disclosed is a method by which registers without tagged parity can be read using the same path that parity tagged registers use. The integrity of the data is not compromised and internal parity errors are detected and flagged as errors.

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Internal Parity Checking And Regeneration for Mixed Parity/Non-Parity Data Sources

Disclosed is a method by which registers without tagged parity can be read using the same path that parity tagged registers use. The integrity of the data is not compromised and internal parity errors are detected and flagged as errors.

The serial link I/O controller contains many registers and data buffers which must be readable using load commands from the system processor. Many of these registers and data buffers are loaded from the link receive circuitry which stores parity with the data. Other registers, such as status and counters, which are changing constantly have no static parity value stored with them.

Due to the number of different data paths and the dynamic nature of some of the readable registers a parity checking/regeneration scheme was developed. All of the data paths were funneled down to a single bus out to the processor. An intelligent parity checking and regeneration circuit is attached to the parity data path at this point. This circuit monitors the addresses of the registers being read and determines whether the register should have correct parity stored. If the parity should be stored and it is not correct after the check, correct parity is generated and an internal channel check is flagged. If the data source does not store parity, correct parity will be generated. Correct parity is generated in both cases so that the I/O controller does not cause a system bu...