Dismiss
InnovationQ will be updated on Sunday, Oct. 22, from 10am ET - noon. You may experience brief service interruptions during that time.
Browse Prior Art Database

Address Error Detection for MICRO Channel Bus Extensions Far From the Host (> 2 Meters)

IP.com Disclosure Number: IPCOM000121517D
Original Publication Date: 1991-Sep-01
Included in the Prior Art Database: 2005-Apr-03
Document File: 2 page(s) / 71K

Publishing Venue

IBM

Related People

Allen, JW: AUTHOR [+3]

Abstract

MICRO CHANNEL* application exists such that the system MICRO CHANNEL bus and an Adapter attached to the MICRO CHANNEL bus are separated by two or more meters. For example, a MICRO CHANNEL Expansion Box might be separated from the system MICRO CHANNEL due to system packaging requirements. This type of expansion box would be composed of an Expansion Adapter inserted into the system MICRO CHANNEL bus driving the Expansion Box, containing additional slots, through a 3-meter cable. See Figure 1.

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

Address Error Detection for MICRO Channel Bus Extensions Far From
the Host (> 2 Meters)

      MICRO CHANNEL* application exists such that the system
MICRO CHANNEL bus and an Adapter attached to the MICRO CHANNEL bus
are separated by two or more meters.  For example, a MICRO CHANNEL
Expansion Box might be separated from the system MICRO CHANNEL due to
system packaging requirements.  This type of expansion box would be
composed of an Expansion Adapter inserted into the system MICRO
CHANNEL bus driving the Expansion Box, containing additional slots,
through a 3-meter cable. See Figure 1.

      The MICRO CHANNEL Architecture expects addressed adapters to
respond to the host by activating a Card Selected Feedback (-CD
SFDBK) Signal notifying the host of their presence.  This must be
accomplished in a specified time period.  If the addressed adapter is
inserted into an expansion box that is far from the system MICRO
CHANNEL bus, this time specification will not be met due to the
signal propagation delay and buffering.

      In order to meet this time specification, the Expansion Adapter
must decode the addresses and generate a Card Selected Feedback for
the adapters in the Expansion Box. This could cause an undetected
error condition under the following condition.  When the Expansion
Adapter receives valid address and parity, it will provide Card
Selected Feedback for the adapter in the Expansion Box.  If during
transmission of the address and parity to the ad...