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Browse Prior Art Database

Down-Loadable Power-On Self-Tests for a Personal Computer System

IP.com Disclosure Number: IPCOM000101220D
Original Publication Date: 1990-Jul-01
Included in the Prior Art Database: 2005-Mar-16
Document File: 2 page(s) / 77K

Publishing Venue

IBM

Related People

Christiansen, RA: AUTHOR [+4]

Abstract

This article describes a technique for use in a personal computer (PC) system to download power on self tests (POSTs) and run them out of RAM rather than store and run them out of read only memory (ROM).

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

Down-Loadable Power-On Self-Tests for a Personal Computer System

       This article describes a technique for use in a personal
computer (PC) system to download power on self tests (POSTs) and run
them out of RAM rather than store and run them out of read only
memory (ROM).

      In some PC systems POSTs reside on an adapter card in ROM and
execute from ROM.  POSTs typically verify the hardware only to the
extent that the PC system can be powered up.  POSTs do not fully
exercise the function of the card.  As PC systems adapter cards
become more intelligent with on-card processors and reliability
availability and serviceability (RAS) requirements change to include
greater power- up testing, the POSTs become more complicated and
require more ROM.  Operational code is written such that it will test
the functionality of the card to compensate for lack of RAS.

      In the technique disclosed herein the majority of POSTs which
currently reside in ROM are moved to the front of the application
code that is downloaded just after power up. These are called down
loadable POSTs (DLPOSTs).

      DLPOSTs are diagnostic code written to verify the functionality
of the PC system adapter card prior to the execution of operational
code.  They will fully exercise each of the feature card's chips to
the extent that coverage is compatible with current and future RAS
requirements.

      The remaining ROM code consists of the following:
      -   Just enough POST code to verify that the hardware
          can be accessed and that the RAM is functional.
      -   Any bootstrap programs that bring up the adapter
          card and download the application code.
      -   Any programmable ROM (PROM) services required by
          the operational code.

      The DLPOSTs are the first modules executed in the application
and be...