Browse Prior Art Database

Automatic Configuration of Special Attachment Hardware Elements

IP.com Disclosure Number: IPCOM000103870D
Original Publication Date: 1993-Feb-01
Included in the Prior Art Database: 2005-Mar-18
Document File: 2 page(s) / 95K

Publishing Venue

IBM

Related People

Cwiakala, R: AUTHOR [+4]

Abstract

A method for automatically generating the ESA/390* channel subsystem control structures required to define a special attachment hardware element as part of the I/O configuration is disclosed. this method minimizes the amount of information that must be manually entered as part of the configuration definition process. It also allows additional flexibility in the hardware to move to improved structures, based on new technology, without customer impact.

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

Automatic Configuration of Special Attachment Hardware Elements

      A method for automatically generating the ESA/390* channel
subsystem control structures required to define a special attachment
hardware element as part of the I/O configuration is disclosed.  this
method minimizes the amount of information that must be manually
entered as part of the configuration definition process.  It also
allows additional flexibility in the hardware to move to improved
structures, based on new technology, without customer impact.

      An implementation of a specialized hardware element
(co-processor) is used as an example.

      An I/O model is used for the definition of this co-processor as
part of the hardware configuration.  This means that the channel
subsystem, within a central processing complex (CPC), views the
co-processor as a single control unit or multiple control units.
Whether the co-processor is viewed as a single control unit or
multiple control units is a function of the number of channel paths
that connect the CPC to the co-processor.  The co-processor is
attached by means of a new channel type, a co-processor attachment
channel (CAC), which is defined in the same manner as an I/O channel.
Point-to-point connection between the channel and the co-processor is
the only topology supported so there is no need to contend with the
complexity of a switch connected or multi-drop topology.

      With this approach, the physical presence or definition of the
co-processor attachment channel is all that is required to handle the
definition of the co-processor hardware element.  As part of
initialization, at power-on-reset, the channel subsystem generates
the appropriate number of control unit and device structures based
upon the number of these CACs that are physically installed or
defined.  The number of device structures generated equals the number
of concurrent operations that each channel can support times the
number of channels.  The number of concurrent operations may be
determined by referencing a tabular representation of the installed
hardware.

      Additional considerations require dealing with the association
of these device structures to control units, number of control unit
structures to generate, and the association of channel paths to the
right control unit construct, especially when the number of paths to
a co-processor from a central processing complex is greater then
eight.  Eight paths are the limit for control units but may not be an
appr...