Browse Prior Art Database

Bi-Directional Address Bus for Memory Cards

IP.com Disclosure Number: IPCOM000117291D
Original Publication Date: 1996-Jan-01
Included in the Prior Art Database: 2005-Mar-31
Document File: 2 page(s) / 46K

Publishing Venue

IBM

Related People

Coteus, PW: AUTHOR [+3]

Abstract

Disclosed is a means to propagate memory card type/configuration information to a system or memory control logic through multiplexed use of other existing interface signals. This scheme reduces cost with fewer memory card and controller pins, while providing increased function without degradation to performance.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 70% of the total text.

Bi-Directional Address Bus for Memory Cards

      Disclosed is a means to propagate memory card
type/configuration information to a system or memory control logic
through multiplexed use of other existing interface signals.  This
scheme reduces cost with fewer memory card and controller pins, while
providing increased function without degradation to performance.

      Semiconductor memory cards are constructed with many different
characteristics (sizes, performance grades, types, etc.).  This
information is commonly conveyed to a memory controller through a
dedicated set of up to ten signal pins on memory card subassemblies.
These pins present a cost to both the memory controller and the
memory card subassembly.

      Multiplexing memory card state on other existing signals
(address, data, control, etc.) between the memory controller and
memory cards provides a cost optimized solution for handling memory
card configuration state.

      The address and data bus signals can be used to transfer memory
card state to the memory controller(s) already connected to any of
these signals.  This is done by providing a low cost tri-state driver
to serve as a Read-Only-Memory (ROM) on the memory card assembly.
This device is used to electrically isolate the card state bits,
connected to the device input pins, from the bus signals attached to
the device output pins.  A dedicated read enable control signal is
used to enable the device to drive the memory card state...