Browse Prior Art Database

Mirrored Processor/Memory Cards

IP.com Disclosure Number: IPCOM000113845D
Original Publication Date: 1994-Oct-01
Included in the Prior Art Database: 2005-Mar-27
Document File: 2 page(s) / 60K

Publishing Venue

IBM

Related People

Brown, JD: AUTHOR [+5]

Abstract

Disclosed is a methodology for minimizing the length of the bus wiring between two groups of processors and memories operating in a tightly-coupled mode.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 67% of the total text.

Mirrored Processor/Memory Cards

      Disclosed is a methodology for minimizing the length of the bus
wiring between two groups of processors and memories operating in a
tightly-coupled mode.

      One strategy for packaging multiple microprocessors in a
tightly-coupled mode is to place several microprocessors (e.g., two
microprocessors) on a card together with some portion of the memory
subsystem.  This minimizes interconnect wiring and impedance mismatch
which would occur if they were packaged separately.  More
microprocessors can be introduced into the system by using two such
cards, interconnecting the processors and memories between the cards
appropriately.  Due to protrusions from the card (e.g., a large
heatsink (13)), the only way of maintaining a short distance between
cards is to arrange them back-to-back as shown the end view of the
figure.

      Observe that Processor/Memory card A (1) and Processor/Memory
card B (2) are exact mirrors of each other.  Also note that the cards
are symmetrical around a horizontal drawn through the middle of the
storage control module M (4).  Because the two cards are mirrored and
packaged back to back, a signal line that comes off one of the cards
through a connector (8) is immediately opposite the receiver of that
line on the other card.  The processors (3), (10), (11) and (12)
connect to the memory DRAM (7) via a set of data control chips
contained in the storage control module (4).  Also populated on each
ca...