Browse Prior Art Database

Power Sequencing Circuit for Multi-Processor Based Computer System

IP.com Disclosure Number: IPCOM000123923D
Original Publication Date: 1999-Jul-01
Included in the Prior Art Database: 2005-Apr-05
Document File: 2 page(s) / 93K

Publishing Venue

IBM

Related People

Mueller, MW: AUTHOR [+3]

Abstract

This disclosure details a method and circuit description for sequencing voltages in a computer system. It furthermore describes a method of reuse for such voltage sequencing circuits.

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This is the abbreviated version, containing approximately 59% of the total text.

Power Sequencing Circuit for Multi-Processor Based Computer System

   This disclosure details a method and circuit description
for sequencing voltages in a computer system.  It furthermore
describes a method of reuse for such voltage sequencing circuits.

   In tomorrow's high-end computer systems, such as enterprise
class SMP systems, silicon technologies are being implemented in
components that require multiple voltages for each device and very
specific requirements on the sequencing of these supply voltages
when powering on the device and powering it off.  These components
also often have specific timing requirements for the amount of time
that a certain voltage must be on before the next voltage can be
applied. The same is true in the case of powering off the device.
The risk of not sequencing these voltages correctly is that the
component can be damaged and the computer rendered inoperable until
the failing board can be replaced.  This type of repair action is to
be avoided in enterprise class systems and this invention presents a
positive method of removing the risk associated with complex voltage
sequencing requirements.

   This invention makes use of a specialized programmable
hardware circuit that is implemented once and reused on multiple
systems by programming the circuit with the correct sequencing
behavior.

   The Figure illustrates the state transition diagram for
the power sequencer circuit.  The power sequencer starts in the off
state either from a...