Dynamic voltage dithering

Patent metadata

Field	Value
Publication number	US-9063707-B2
Application number	US-201414154531-A
Country	US
Kind code	B2
Filing date	Jan 14, 2014
Priority date	Jun 18, 2010
Publication date	Jun 23, 2015
Grant date	Jun 23, 2015

Abstract

A request for a high voltage mode is received and a high voltage timer is started in response to determining that a remaining amount of high voltage credits exceeds a voltage switch threshold value. A switch to the high voltage mode is made in response to the request. A low voltage mode is switched to in response to an indication. The request may be received from an application running on a data processing system. If the indication is that the high voltage timer has expired, a low voltage timer is started in response to switching to low voltage mode. If the high voltage request is still active when the low voltage timer expires, a switch back to high voltage mode occurs and a new high voltage timer is started.

First claim

What is claimed is:

1. An apparatus, comprising:
a first timer;
a second timer;
control circuitry coupled to the first timer and the second timer, wherein the control circuitry is configured to:
select a high voltage time budget;
select a low voltage time budget;
switch at least one component of a computing system to a high voltage mode responsive to receiving a first request, and responsive to a determination that the high voltage time budget is greater than a transition threshold value;
start the first timer responsive to switching to the high voltage mode;
switch the at least one component of the computing system to a low voltage mode responsive to receiving a first event;
start the second timer responsive to switching to the low voltage mode; and
switch the at least one component of the computing system back to the high voltage mode responsive to receiving a second event and a second request.

2. The apparatus of claim 1 , wherein to select the high voltage time budget, the control circuitry is further configured to multiply a percentage and a cycle period.

3. The apparatus of claim 1 , wherein to select the low voltage time budget, the control circuit is further configured to determine a difference between the cycle period and the high voltage time budget.

4. The apparatus of claim 1 , wherein the first event includes an indication that the first timer has expired.

5. The apparatus of claim 1 , wherein to switch the at least one component of the computing system to the high voltage mode responsive to receiving the first request, the control circuitry is further configured to switch to the high voltage mode responsive to receive the first request from an application program being executing on the computing system.

6. The apparatus of claim 1 , wherein the transition threshold value is dependent upon an overhead cost of switching to the high voltage mode.

7. A method, comprising:
selecting a high voltage time budget for a computing system;
selecting a low voltage time budget for the computing system;
switching at least one component of the computing system to a high voltage mode responsive to receiving a first request, and responsive to a determination that the high voltage time budget is greater than a transition threshold value;
switching the at least one component of the computer system to a low voltage mode responsive to receiving a first event; and
switching the at least one component of the computing system back to the high voltage mode responsive to receiving a second event and a second request.

8. The method of claim 7 , wherein selecting the high voltage time budget comprises multiplying a percentage and a cycle period.

9. The method of claim 8 , wherein selecting the low voltage time budget comprises determining a difference between the cycle period and the high voltage time budget.

10. The method of claim 7 , wherein the transition threshold value is dependent upon an overhead cost of switching to the high voltage mode.

11. The method of claim 7 , wherein receiving the first event comprises receiving an indication that the received first request has been canceled.

12. The method of claim 7 , wherein switching the at least one component of the computing system to the high voltage mode comprises starting a first timer.

13. The method of claim 7 , wherein switching the at least one component of the computing system to the low voltage mode comprises starting a second timer.

14. A computer-accessible non-transitory storage medium having program instructions stored therein that, in response to execution by a processor, cause the processor to perform operations comprising:
determining a low voltage portion of a total operating clock period during which a computer system is operated at a low voltage, wherein the low voltage portion is a minimum period;
switching at least one component of the computing system to operate at a high voltage responsive to receiving a first request, and responsive to a determination that an allowable high voltage portion of the total operating clock period is greater than a predetermined amount of time associated with performing the switch;
switching the at least one component of the computing system to operate at the low voltage responsive to receiving a first event; and
switching the at least one component of the computing system back to operate at the high voltage responsive to receiving a second event and a second request.

15. The computer-accessible non-transitory storage medium of claim 14 , wherein the allowable high voltage portion of the total operating clock period comprises a percentage of the total operating clock.

16. The computer-accessible non-transitory storage medium of claim 15 , wherein determining the low voltage portion of the total operating clock period comprises determining a difference between the total operating clock period and the allowable high voltage portion.

17. The computer-accessible non-transitory storage medium of claim 14 , wherein the transition threshold value is dependent upon an overhead cost of switching to operate at the high voltage.

18. The computer-accessible non-transitory storage medium of claim 14 , wherein receiving the first event comprises receiving an indication that the received first request has been canceled.

19. The computer accessible non-transitory storage medium of claim 14 , wherein switching the at least one component of a computing system to operate at the high voltage comprises starting a first counter.

20. The computer-accessible non-transitory storage medium of claim 14 , wherein switching the at least one component of the computing system to operate at the low voltage comprises starting a second timer.

Assignees

• Apple Inc

Inventors

• De Cesare Joshua
• Andrews Jonathan Jay

Classifications

• G06F1/189 Primary

  Power distribution · CPC title

• G06F1/3203 Primary

  Power management, i.e. event-based initiation of a power-saving mode · CPC title

• G06F1/3296

  by lowering the supply or operating voltage · CPC title

• Y02B60/1285

  Cross-Sectional Technologies · mapped topic

• G06F1/32 Primary

  Means for saving power · CPC title