Power controller and power control method

• US 20050240784A1
• Filed: 04/25/2005
• Published: 10/27/2005
• Est. Priority Date: 04/27/2004
• Status: Active Grant

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Sugasawa, Masashi
• Granted Patent: US 7,441,127 B2
• Time in Patent Office: Days
• US Class Current: 713/300
• CPC Class Codes: G06F 1/266 Arrangements to supply power to external peripherals either directly from the computer or under computer control, e.g. supply of power through the communication port, computer controlled power-strips
• CPC Class Codes: G06F 1/28 Supervision thereof, e.g. detecting power-supply failure by out of limits supervision
• CPC Class Codes: G06F 1/3203 Power management, i.e. event-based initiation of a power-saving mode
• CPC Class Codes: G06F 1/324 by lowering clock frequency
• CPC Class Codes: G06F 1/325 Power saving in peripheral device
• CPC Class Codes: Y02D 10/00 Energy efficient computing, e.g. low power processors, power management or thermal management

Abstract

A power controller includes a power detector detecting supply of first power given a predetermined power level and second power given a power level lower than the first power, a supply power switch supplying a storage with the first power when the power detector detects supply of the first power and supplying the storage with the second power switching from the first power to the second power when the power detector detects supply of the second power only, and a data transfer rate controller setting a data transfer rate between a predetermined data transfer source/destination and the storage to a second data transfer rate lower than a first data transfer rate coupled with the supply of the first power when supply of the second power only is detected, to reduce power consumption of the storage in comparison to power consumed by a data transfer at the first data transfer rate.

Claims

1. A power controller comprising:

power detection means for detecting supply of first power given a predetermined power level and second power given a power level lower than the power level given to the first power;

supply power switch means for supplying storage means for storing data in a storage medium with the first power when the power detection means detects supply of the first power, and supplying the storage means with the second power after switching power from the first power to the second power when the power detection means detects supply of the second power only; and

data transfer rate control means for setting a data transfer rate between a predetermined data transfer source or data transfer destination and the storage means to a second data transfer rate lower than a first data transfer rate coupled with the supply of the first power when supply of the second power only is detected, to thereby reduce power consumption of the storage means in comparison to power consumed by a data transfer performed at the first data transfer rate.

2. The power controller according to claim 1, wherein

the data transfer rate control means sets the second data transfer rate before the data transfer at the second data transfer rate is started and, maintains the second data transfer rate even when the first power is supplied after the data transfer starts.

3. The power controller according to claim 1, wherein

the data transfer rate control means sets the data transfer rate by switching among a plurality of predetermined data transfer modes.

4. The power controller according to claim 1, wherein

the second power is supplied by means of a data communication cable used for performing a data transfer with an external device.

5. The power controller according to claim 4, wherein

the data communication cable is a Universal Serial Bus (USB) cable and

the second power is USB power.

6. A power control method comprising:

a power detection step of detecting supply of first power given a predetermined power level and second power given a power level lower than the power level of the first power;

a supply power switch step of supplying storage means for storing data in a storage medium with the first power when supply of the first power is detected in the power detection step and supplying the storage means with the second power after switching power source from the first power to second power when supply of the second power only is detected in the power detection step; and

a data transfer rate control step of setting a data transfer rate between a predetermined data transfer source or data transfer destination and the storage means to a second data transfer rate lower than a first data transfer rate coupled with supply of the first power when supply of the second power only is detected, to thereby reduce power consumption of the storage means in comparison to power consumed by a data transfer at the first data transfer rate.

7. A power controller comprising:

a power detector detecting supply of first power given a predetermined power level and second power given a power level lower than the power level given to the first power;

a supply power switch supplying a storage for storing data in a storage medium with the first power when the power detector detects supply of the first power, and supplying the storage with the second power after switching power from the first power to the second power when the power detector detects supply of the second power only; and

data transfer rate controller setting a data transfer rate between a predetermined data transfer source or data transfer destination and the storage to a second data transfer rate lower than a first data transfer rate coupled with supply of the first power when supply of the second power only is detected, to thereby reduce power consumption of the storage in comparison to power consumed by a data transfer performed at the first data transfer rate.

8. The power controller according to claim 7, wherein

the data transfer rate controller sets the second data transfer rate before the data transfer at the second data transfer rate is started and, maintains the second data transfer rate even when the first power is supplied after the data transfer starts.

9. The power controller according to claim 7, wherein

the data transfer rate controller sets the data transfer rate by switching among a plurality of predetermined data transfer modes.