System and method for task performance based dynamic distributed power management in a computer system and design method therefor

• US 6,115,823 A
• Filed: 08/18/1999
• Issued: 09/05/2000
• Est. Priority Date: 06/17/1997
• Status: Expired due to Term

• Current Assignee: St Clair Intellectual Property Consultants Incorporated
• Original Assignee: Amphus, Inc.
• Inventors: Fung, Henry T., Velasco, Francisco, Phung, Xuyen N., Mitchell, Phillip M.
• Primary Examiner(s): Etienne, Ario
• Application Number:
  US09/376,271
• Time in Patent Office: 384 Days
• Field of Search: 713/300-340, 710/8, 710/9, 710/10, 710/15, 710/16, 710/18
• US Class Current: 713/322
• CPC Class Codes: G06F 1/3203 Power management, i.e. event-based initiation of a power-saving mode
• CPC Class Codes: G06F 1/3228 Monitoring task completion, e.g. by use of idle timers, stop commands or wait commands
• CPC Class Codes: G06F 1/3237 by disabling clock generation or distribution
• CPC Class Codes: G06F 1/324 by lowering clock frequency
• CPC Class Codes: G06F 1/325 Power saving in peripheral device
• CPC Class Codes: G06F 1/3259 Power saving in cursor control device, e.g. mouse, joystick, trackball
• CPC Class Codes: G06F 1/3271 Power saving in keyboard
• CPC Class Codes: G06F 1/3275 Power saving in memory, e.g. RAM, cache
• CPC Class Codes: Y02D 10/00 Energy efficient computing, e.g. low power processors, power management or thermal management

Abstract

In a computer system having a device and a communications link for communicating with the device. A method for dynamically managing power consumption by the computer system comprises associating a particular device identifier with the device. Communications are monitored over the communications link to determine whether the communications include the particular device identifier. A clock input is withheld from the device when the communications do not include the particular device identifier. Clock input is provided to the device only when the communications include the particular device identifier. The clock input causes the device to transition from a non-operational power conservative state to an operational state wherein the device consumes more power than in the non-operational state. A performance requirement is established for a task to be executed. Clock frequency is dynamically controlled according to the performance requirement established for the task being executed.

Claims

1. In a computer system having a device, and a communications link for communicating with said device, a method for dynamically managing power consumption by said computer system comprising:

associating a particular device identifier with said device;

monitoring communications over said communications link to determine whether said communications include said particular device identifier;

withholding a clock input from said device when said communications do not include said particular device identifier; and

providing said clock input to said device only when said communications include said particular device identifier;

said providing of said clock input causing said device to transition from a non-operational power conservative state to an operational state wherein said device consumes more power than in said non-operational state;

establishing a performance requirement for a task to be executed; and

dynamically controlling a frequency of said clock input according to the performance requirement established for the task being executed.

2. A distributed power management apparatus for a computer system having a processor and at least one bus coupled for communication with said processor, said apparatus comprising:

a plurality of devices each having a particular unique device identifier and coupled for communication with said bus;

a plurality of monitoring circuits monitoring communications over said bus during each predetermined time period to determine any device identifiers broadcast over said bus during said predetermined time period and comparing said broadcast device identifiers to said particular unique device identifiers, each of said monitoring circuits being associated with only one of said devices and only one of said particular unique device identifiers; and

a control circuit selectively controlling a device operating input to a particular device when none of said broadcast device identifiers match said unique particular device identifier, and for dynamically controlling a characteristic of said device operating input to its associated device when one of said broadcast device identifiers match said unique particular device identifier for its associated device.

3. The distributed power management apparatus in claim 2, wherein said dynamically controlling a characteristic comprises dynamically controlling a frequency of a clock device operating input according to a performance requirement established for a task being executed.

4. In a computer system having a device, and a communications link for communicating a broadcast device identifier to said device, said computer system operating to perform a plurality of overlapping tasks in a multi-tasking environment, a method for managing power consumption in said computer system comprising:

associating a unique device identifier with said device;

monitoring communications over said communications link, by said device, during a time period to determine broadcast device identifiers contained within said monitored communication;

comparing said broadcast device identifier with said unique device identifier associated with said device to determine whether said broadcast device identifiers match said unique device identifier for said device;

controlling a device operating input to said device in response to said broadcast device identifier matching or not matching said unique device identifier associated with said device; and

providing said device operating input to said device only when said broadcast device identifier matches said unique device identifier for said device;

modifying a characteristic of said operating input in response to performance requirements associated with a task using said device for said task;

said computer system operating to perform a plurality of substantially simultaneous operational tasks in a multi-tasking environment,

broadcasting said unique device identifier only during a time period in which said device is actually being accessed by said computer system, independent of whether a particular processing task using said device associated with said unique device identifier during said time period has been completed; and

controlling said characteristic to match said performance requirement during a time period in which said device is actually being accessed by said computer system to perform said task associated with said performance requirement.