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Method of Sharing Address Space in Testing Personal Computer Systems' Memory

IP.com Disclosure Number: IPCOM000107628D
Original Publication Date: 1992-Mar-01
Included in the Prior Art Database: 2005-Mar-22
Document File: 3 page(s) / 100K

Publishing Venue

IBM

Related People

Guha, S: AUTHOR [+2]

Abstract

Described is a method of sharing address space in testing personal computer (PC) systems' memory in virtual memory mode. The method enables power-on self-test (POST) operations to fully test the Micro Channel* (MC) memory regardless of the microprocessor used in the system.

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Method of Sharing Address Space in Testing Personal Computer Systems' Memory

       Described is a method of sharing address space in testing
personal computer (PC) systems' memory in virtual memory mode.  The
method enables power-on self-test (POST) operations to fully test the
Micro Channel* (MC) memory regardless of the microprocessor used in
the system.

      Typically, the amount of extended memory used in MC systems is
limited due to the capabilities of the microprocessor.  As a result,
the testing of an adapter memory in systems with a sixteen-bit
microprocessor becomes time consuming and impossible when the PC
memory exceeds 16 megabytes (MBs).  The concept described herein
utilizes the testing adapter's read-only memory (ROM) space as a
virtual memory window so as to enable POST operations to function
with any type of microprocessor in the PC.

      Generally, test programs, (i.e., POST) exercise the MC memory
adapter each time the PC is powered on so as to verify the adapter's
functionality.  The adapter's memory is defined as being
conventional, extended and expanded. Conventional memory is located
between addresses 0-640 kilobytes (KBs).  Extended memory, also
called real memory, is limited by the addressability of the
microprocessor. Extended memory is located in the address range above
one MB.

      Expanded memory, also called virtual memory, provides access to
32 MBs of physical memory through a 192 KB logical address range.
Expanded...