Power Supply Control Circuit and Electronic Circuit

• US 20080197703A1
• Filed: 02/13/2006
• Published: 08/21/2008
• Est. Priority Date: 02/16/2005
• Status: Active Grant

• Current Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Original Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Inventors: Tomita, Hiroto
• Granted Patent: US 7,696,641 B2
• Time in Patent Office: Days
• US Class Current: 307/31
• CPC Class Codes: G06F 1/3203 Power management, i.e. event-based initiation of a power-saving mode
• CPC Class Codes: G06F 1/3243 Power saving in microcontroller unit
• CPC Class Codes: G06F 1/3287 by switching off individual functional units in the computer system
• CPC Class Codes: H02J 1/14 Balancing the load in a network
• CPC Class Codes: H02J 2310/60 Limiting power consumption in the network or in one section of the network, e.g. load shedding or peak shaving
• CPC Class Codes: H02J 3/144 Demand-response operation of the power transmission or distribution network
• CPC Class Codes: Y02D 10/00 Energy efficient computing, e.g. low power processors, power management or thermal management

Abstract

A power supply control circuit (3) having control of the supply and shutoff of electrical power from a power source (2), and including a request-receiving unit (11) operable to receive a power shutoff-requesting signal (10) from each of a plurality of functional blocks, in which each of the plurality of functional blocks has a predetermined processing function, a switchover unit (12) operable to provide switchover between the supply and shutoff of the electrical power from the power source to each of the plurality of functional blocks, and a control unit (13) operable to control the switchover unit (12) in accordance with the power shutoff-requesting signal (10) received by the request-receiving unit (11). The power supply control circuit (3) provides proper control over the supply and shutoff of the electrical power for each of the functional blocks, whereby each of the functional blocks consumes reduced electrical power.

Claims

1. A power supply control circuit having control of supply and shutoff of electrical power from a power source, comprising:

a request-receiving unit operable to receive a power shutoff-requesting signal from each of a plurality of functional blocks, each of the plurality of functional blocks having a predetermined processing function;

a switchover unit operable to provide switchover between the supply and shutoff of the electrical power from the power source to each of the plurality of functional blocks; and

a control unit operable to control said switchover unit in accordance with the power shutoff-requesting signal received by said request-receiving unit.

2. A power supply control circuit as defined in claim 1, wherein the power shutoff-requesting signal is a processing end signal sent out by at least one of the plurality of functional blocks.

3. A power supply control circuit as defined in claim 1, wherein the power shutoff-requesting signal is a notification signal sent out at definite time intervals by at least one of the plurality of functional blocks.

4. A power supply control circuit as defined in claim 1, wherein the power shutoff-requesting signal contains information on a period of time that elapses from the shutoff of the electrical power until the supply of the electrical power.

5. A power supply control circuit as defined in claim 1, wherein said control unit comprises:

a power shutoff-permitting unit operable to permit start and end of the shutoff of the electrical power in accordance with the power shutoff-requesting signal received by said request-receiving unit.

6. A power supply control circuit as defined in claim 5, wherein said power shutoff-permitting unit permits the start of the shutoff of the electrical power in accordance with the power shutoff-requesting signal from one of the plurality of functional blocks as well as another power shutoff-requesting signal from a further one of the plurality of functional blocks, the further one of the plurality of functional blocks having a processing dependent relationship with the one of the functional blocks.

7. A power supply control circuit as defined in claim 5, wherein, when said request-receiving unit receives one power shutoff-requesting signal from one of the plurality of functional blocks, said power shutoff-permitting unit permits the start and end of the shutoff of the electrical power, depending upon whether there is present another power shutoff-requesting signal sent out by a further one of the plurality of functional blocks, the further one of the functional blocks having a processing dependent relationship with the one of the functional blocks.

8. A power supply control circuit as defined in claim 5, wherein said power shutoff-permitting unit permits the start of the shutoff of the electrical power when said request-receiving unit receives power shutoff-requesting signals from all of ones of the plurality of functional blocks, the ones of the plurality of functional blocks sharing a processing dependent relationship with each other.

9. A power supply control circuit as defined in claim 5, wherein said power shutoff-permitting unit comprises:

an information-storing unit operable to store information on a processing dependent relationship.

10. A power supply control circuit as defined in claim 9, wherein said information-storing unit is rewritable in accordance with an external factor.

11. A power supply control circuit as defined in claim 5, wherein said power shutoff-permitting unit comprises:

a shutoff time-measuring unit operable to measure a certain period of time that elapses after receipt of the power shutoff-requesting signal, whereby said power shutoff-permitting unit permits the start of the shutoff of the electrical power after the certain period of time elapses.

12. A power supply control circuit as defined in claim 5, wherein said power shutoff-permitting unit comprises:

a resumption time-measuring unit operable to measure a certain period of time that elapses after the start of the shutoff of the electrical power, whereby said power shutoff-permitting unit permits the end of the shutoff of the electrical power after the certain period of time elapses.

13. An electronic circuit comprising:

a plurality of functional blocks, each of which has a predetermined processing function;

a request-receiving unit operable to receive a power shutoff-requesting signal from each of said plurality of functional blocks;

a switchover unit operable to provide switchover between supply and shutoff of electrical power from a power source to each of said plurality of functional blocks; and

a control unit operable to control said switchover unit in accordance with the power shutoff-requesting signal received by said request-receiving unit.

14. An electronic circuit as defined in claim 13, wherein said control unit comprises:

a power shutoff-permitting unit operable to permit start and end of the shutoff of the electrical power in accordance with the power shutoff-requesting signal received by said request-receiving unit.

15. An electronic circuit as defined in claim 13, further comprising:

an output value-fixing unit operable to fix a logical value of an output signal from each of said plurality of functional blocks,

wherein said output value-fixing unit provides a fixed logical value of an output signal from each one of said plurality of functional blocks when the each one of said plurality of functional blocks is interrupted from the supply of the electrical power.

16. An electronic circuit defined in claim 15, wherein an electronic element included in said output value-fixing unit is lower in operating voltage than an electronic element included in the each one of said plurality of functional blocks.

17. An electronic circuit defined in claim 15, wherein an electronic element included in said output value-fixing unit is lower in threshold voltage than an electronic element included in the each one of said plurality of functional blocks.

18. An electronic device comprising:

a plurality of functional blocks, each of which has a predetermined processing function;

a request-receiving unit operable to receive a power shutoff-requesting signal from each of said plurality of functional blocks;

a switchover unit operable to provide switchover between supply and shutoff of electrical power from a power source to each of said plurality of functional blocks;

a control unit operable to control said switchover unit in accordance with the power shutoff-requesting signal received by said request-receiving unit; and

a central processing unit operable to control the predetermined processing function of each of said plurality of functional blocks.

19. An electronic device as defined in claim 18, wherein said electronic device is a portable terminal.

20. An electronic device as defined in claim 18, wherein said electronic device is a notebook-sized personal computer.