Browse Prior Art Database

Diagnostics Machine Check Handling

IP.com Disclosure Number: IPCOM000102653D
Original Publication Date: 1990-Dec-01
Included in the Prior Art Database: 2005-Mar-17
Document File: 2 page(s) / 66K

Publishing Venue

IBM

Related People

Benignus, DM: AUTHOR [+2]

Abstract

A method is described which identifies what diagnostics was being run when a system crash (abend) occurs.

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

Diagnostics Machine Check Handling

       A method is described which identifies what diagnostics
was being run when a system crash (abend) occurs.

      System crashes sometimes occur while running diagnostics on a
system.  This is normally caused by the Field Replaceable Unit (FRU)
that is being tested at the time of the crash.  Multiple FRUs may be
tested at different times whenever a diagnostic is run.  If a crash
occurs, there is no easy way for the user to determine what
diagnostic was running unless some type of indication is given that
identifies what was being tested.  To isolate this type of problem
when no indication is given requires a long involved procedure which
the Customer Engineer has to perform.  The procedure includes
removing FRUs from the system and running diagnostics several times.

      On a computer, a sequence of numbers is displayed whenever a
system crash occurs.  These numbers identify the type of crash that
occurred.

      Whenever diagnostics are run on a computer, additional
information is concatenated to the crash information.  This
information identifies what FRU was being tested when the crash
occurred.

      Whenever a crash occurs, the system Machine Check Handler puts
a sequence of sets of 3 digits into an area in NVRAM LED Save Area.
This information is then displayed under control of the
On-Card-Sequencer (OCS) microprocessor and Reset Button.  Note that
the OCS is an 8051-type microprocessor OCS.  The information is
always of fixed length and includes the following:
      -    '888' to signal that a sequence of information is
           to be displayed.
      -    '102 to indicate that a syste...