Browse Prior Art Database

Dual Low-Cost, High-Performance Memory Configuration Scheme Using Common Planar

IP.com Disclosure Number: IPCOM000111256D
Original Publication Date: 1994-Feb-01
Included in the Prior Art Database: 2005-Mar-26
Document File: 2 page(s) / 83K

Publishing Venue

IBM

Related People

Countryman, GJ: AUTHOR [+3]

Abstract

This invention disclosure describes a scheme to provide a low-cost minimal memory configuration with reduced load characteristics and a high-performance configuration using one common planar. Two of the critical configuration decisions in workstation memory subsystems are cost and performance. A low-cost system requires a minimal set of memory cards. In this configuration memory cards are added serially by dotting them onto a common data bus. Eventually, the data bus is slowed down due to the extra loads. A high performance system is achieved by spreading the memory cards out in parallel and providing a wider data bus to memory. This invention disclosure provides a mechanism to achieve both configurations with a single common planar card. In addition it cuts the memory data bus loads in half for the low cost configuration.

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

Dual Low-Cost, High-Performance Memory Configuration Scheme Using
Common Planar

      This invention disclosure describes a scheme to provide a
low-cost minimal memory configuration with reduced load
characteristics and a high-performance configuration using one common
planar.  Two of the critical configuration decisions in workstation
memory subsystems are cost and performance.  A low-cost system
requires a minimal set of memory cards.  In this configuration memory
cards are added serially by dotting them onto a common data bus.
Eventually, the data bus is slowed down due to the extra loads.  A
high performance system is achieved by spreading the memory cards out
in parallel and providing a wider data bus to memory.  This invention
disclosure provides a mechanism to achieve both configurations with a
single common planar card.  In addition it cuts the memory data bus
loads in half for the low cost configuration.

      Consider the case of 2-word memory cards being used to provide
4 and 8-word systems.  The 8-word memory interface requires 4 2-word
memory cards.  However, a 4-word system requires only 2 2-word memory
cards and can therefore be priced much lower when minimally
configured.  Furthermore, to add more memory in the 8-word system, a
customer must purchase another set of 4 memory cards, but the 2-word
system can be expanded 2 memory cards at a time.

      By partioning the memory card busses and adding minimal logic
to the processor chips, a common planar can be designed for both the
4-word and 8-word systems.

Some of the advantages of a common planar follow:

o   Only one planar needs to be designed, tested, and kept in
    inventory.

o   System manufacturing has the flexibility to use the common planar
    for either the 4 or 8-word systems depending on whichever is
    presently in demand.

o   The 4-word system planar can be populated at the last moment with
    either 2, 4, 6, or 8 connectors according to the product...