Browse Prior Art Database

Full Duplex Ethernet Adapter

IP.com Disclosure Number: IPCOM000113683D
Original Publication Date: 1994-Sep-01
Included in the Prior Art Database: 2005-Mar-27
Document File: 2 page(s) / 60K

Publishing Venue

IBM

Related People

Allen, JJ: AUTHOR [+3]

Abstract

An Ethernet adapter which is capable of full duplex operation when connected point to point to a switched Ethernet hub is disclosed. This full duplex adapter is implemented with components originally intended for use in CSMA/CD Ethernet adapters which operate only in half duplex mode.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 61% of the total text.

Full Duplex Ethernet Adapter

      An Ethernet adapter which is capable of full duplex operation
when connected point to point to a switched Ethernet hub is
disclosed.  This full duplex adapter is implemented with components
originally intended for use in CSMA/CD Ethernet adapters which
operate only in half duplex mode.

This Ethernet adapter is composed of three main building blocks as
shown in Fig. 1.
  1.  Micro Channel* Bus Master System Interface Chip
  2.  Multiprotocol Chip (MPC)
  3.  Ethernet Interface Chip

      The media for CSMA/CD 10 Base-T Ethernet is Unshielded Twisted
Pair (UTP) cable.  One pair of wires is used for transmitting data
and another pair is used for receiving data.  For CSMA/CD Ethernet,
only one transmitter in the network can be transmitting, because
CSMA/CD Ethernet is a shared media local area network.  If more than
one transmitter is active, a collision occurs.  The adapters that are
transmitting detect the collision and stop transmitting.

      With the advent of Full Duplex Switched Ethernet, a dedicated
point to point path exists for each adapters transmitter and receiver
as shown in Fig. 2.  The Full Duplex Switched Ethernet Hub provides
isolation for each transmit and each receive path such that
collisions do not occur.

      This implementation takes advantage of a diagnostic function
that is built into the design of the Etherstreamer* chip set.  This
implementation uses the capability provided by the dia...