Browse Prior Art Database

Surface Mounted Memory Module Sensing Technique

IP.com Disclosure Number: IPCOM000106651D
Original Publication Date: 1993-Dec-01
Included in the Prior Art Database: 2005-Mar-21
Document File: 2 page(s) / 40K

Publishing Venue

IBM

Related People

Casavant, P: AUTHOR [+2]

Abstract

Described is a hardware implementation to provide a means of detecting the presence of surface mounted memory modules, as used on printed circuit boards. The technique alters standard memory modules so as to enable diagnostics to flag memory modules for installation detection.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 87% of the total text.

Surface Mounted Memory Module Sensing Technique

      Described is a hardware implementation to provide a means of
detecting the presence of surface mounted memory modules, as used on
printed circuit boards.  The technique alters standard memory modules
so as to enable diagnostics to flag memory modules for installation
detection.

      Typically, the amount of memory installed in a computer system
is determined through software.  Software determination is adequate
for good memory modules, however it is not considered comprehensive
enough when defective memories were installed in the system.

      Single In-line Memory Modules (SIMMs) were designed to overcome
this installation problem by utilizing a dedicated grounding pin to
detect the presence of a SIMM on a circuit board.  A pull-up resistor
is connected to the pin from the memory controller such that if a
SIMM is not installed, the circuitry will so indicate.  However,
industry standard memory modules do not utilize a dedicated sensing
pin and therefore detection cannot be accomplished as with the SIMMs.

      The concept described herein provides a means of detecting the
presence of mounted memory modules without requiring a dedicated
detection pin.  This is accomplished by splitting the solder pad at
one of the ground pins of the memory module so as to isolate the
circuit wiring from the memory controller.  A pull-up resistor is
inserted in the sense pin circuit so as to allow the controller...