Browse Prior Art Database

Start-Up Master Processor Selection Method for Multi-Processor Systems

IP.com Disclosure Number: IPCOM000101934D
Original Publication Date: 1990-Sep-01
Included in the Prior Art Database: 2005-Mar-17
Document File: 2 page(s) / 77K

Publishing Venue

IBM

Related People

Eng, RC: AUTHOR [+3]

Abstract

A technique is described for providing a start-up master processor selection, when identical processing units are used in a multi-processing computer system. The technique establishes one of the processing units as the controlling unit which initializes all of the units on the processing bus.

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

Start-Up Master Processor Selection Method for Multi-Processor Systems

       A technique is described for providing a start-up master
processor selection, when identical processing units are used in a
multi-processing computer system.  The technique establishes one of
the processing units as the controlling unit which initializes all of
the units on the processing bus.

      In a multi-processing system, a number of identical processing
units are connected together by means of the system bus.  Although
the processors operate independently, the system bus can be used by
only one processor at a time. System resources, such as controlling
the bus, direct memory access, system timers and clocks and memory
refresh controls are shared by all processing units in the system.
These resources are placed in a separate system resource unit (SRU)
connected to the bus.  Direct access storage devices (DASD) and other
input/output devices can be placed on the bus, so as to be accessible
to all of the processing units.

      In order to provide for the proper control of a
multi-processing system, one processing unit must take control of the
bus during power- on, or system reset, so as to set-up each of the
other processing units and to coordinate the starting of the entire
system.  This processor is designated the "First Master", since it is
master of the bus at start- up.  With all of the processing units in
the system identical, the start-up master processor selection method
provides a predictable and repeatable method whereby one of the
processing units will be selected to be the First Master.

      At power-up or system reset, all of the processing units drive
an open-collector line on the system, called Ready, to a logical low
state. Each processing unit will hold this line low until it has
completed enough of its self-testing to be certain that it is capable
of controlling the bus as the master.  After the...