Browse Prior Art Database

Sixteen Full-Duplex Port High-Speed Data Switch

IP.com Disclosure Number: IPCOM000036542D
Original Publication Date: 1989-Oct-01
Included in the Prior Art Database: 2005-Jan-29
Document File: 3 page(s) / 69K

Publishing Venue

IBM

Related People

Chang, LL: AUTHOR

Abstract

This article describes a scheme to implement a high-speed full-duplex data switch by configuring some off-the-shelf half-duplexed semiconductor switch modules.

This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 54% of the total text.

Page 1 of 3

Sixteen Full-Duplex Port High-Speed Data Switch

This article describes a scheme to implement a high-speed full-duplex data switch by configuring some off-the-shelf half-duplexed semiconductor switch modules.

In data communication systems, higher data rates are an important requirement due to the availability of higher speed hardware and the greater amount of data that needs to be transferred among users. Also, the need of a "switched" (shared) circuit concept for providing a physical path to multiple users becomes more obvious because for a user, the requirement of communicating with more than one other user becomes more desirable (e.g., a host to more than one other host or a channel to more than one other control unit) and the high operating expense of high-speed transmission medias (e.g., T1, T3, etc.).

In the scheme disclosed herein a sixteen-port full-duplexed high speed data switch is developed to accommodate these requirements by uniquely configuring some off-the-shelf half-duplexed semiconductor switch modules.

A TI's digital crossbar switch (DCS) module is selected to be the basic building block of this high-speed data switch. The DCS supports sixty-four bidirectional data I/Os in the sixteen nibble (4-bit) ports. By properly programming the DCS internal control registers any of the sixteen nibble ports can be connected to any of the other fifteen nibble ports, as shown in Fig. 1. The bandwidth of every I/O line is 40 MHz. Converting this into mega bit per second (MBPS) data rate is an impressive 160 MBPS (40 MHz x 4).

(Image Omitted)

Because of the need to have a full-duplex data switch in this application DCS modules have to be configured differently. There are a number of ways to configure DCS to make a full-duplex switch. In the scheme described in this article to configure DCS that any number of full-duplex ports can be attained without creating a complex control circuit.

A single sixteen bidirectional nibble port DCS module can be configured to implement an eight full-duplex port switch. Eight of the sixteen bidirectional nibble ports can be programmed as input only ports and the other eight ports can be programmed as output only ports. As indicated in the basic configuration diagram of Fig. 2 every user channel's transmitting line (TCO -- TC7) can be connec...