JP2011008343A - Electronic equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To achieve power saving in a display circuit of electronic equipment.SOLUTION: A display driver 201 detects that the transition of a display circuit including a GPU (Graphic Processing Unit) 116 to a power saving mode is possible according to processing on an application program 202, for example, the start processing of the application program by a processing detection part 501. When it is detected that the transition of the display circuit to the power saving mode is possible, a power saving mode setting part 502 sets the power saving mode to the display circuit, and decreases power consumption by decreasing the operating frequency of the GPU 116.

Description

  The present invention relates to an electronic device including a display circuit.

  Conventionally, electronic devices such as personal computers have been required to reduce power consumption.

  For example, the electronic device described in Patent Document 1 consumes power by lowering the backlight of an LCD (Liquid Crystal Display) when the application enters an operation waiting state that does not require an input operation. We are trying to reduce it.

JP-A-11-126118

  However, in the prior art, power consumption is reduced only by reducing the backlight brightness. For this reason, further reduction of power consumption in the display circuit has been demanded.

  The present invention has been made in consideration of the above-described circumstances, and an object thereof is to provide an electronic device capable of saving power in a display circuit.

  In order to solve the above problems, the present invention relates to a display circuit including a GPU (Graphic Processing Unit) that operates by shifting from a first operation mode to a second operation mode for power saving, and an application program. Along with the processing, the detection circuit detects that the display circuit can shift to the second operation mode, and detects that the detection circuit can shift to the second operation mode. In this case, the display circuit includes setting means for setting the display circuit to the second operation mode in order to lower the operating frequency of the GPU.

  According to the present invention, when it is detected that the display circuit can shift to the second operation mode in which power consumption is reduced during execution of the process for the application program, the display circuit By shifting to the operation mode, it is possible to save power in the display circuit.

1 is an external view illustrating a configuration of an electronic device according to an embodiment. The block diagram which shows the system configuration | structure of the personal computer in this embodiment. The block diagram which shows the structural example of GPU in this embodiment. The figure which shows the relationship of the software related to the display circuit in this embodiment. The flowchart which shows the power saving function process with respect to the display circuit by the display driver in this embodiment.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is an external view illustrating a configuration of an electronic device according to the present embodiment. This electronic device is realized as, for example, a notebook-type portable personal computer 10 that can be driven by a battery. The personal computer 10 in this embodiment is mounted with a display circuit including a graphics processing unit (GPU) that executes display processing for displaying an image on a display. In the present embodiment, the power consumption of the display circuit is reduced by executing the power saving function process for reducing the power consumption of the display circuit in accordance with the processing for the application program. The processing for the application program here is important because it does not require input operation by the user even when the processing load on the CPU is heavy, such as application program startup processing and data download via the network. There is not processing.

  FIG. 1 is a perspective view of the personal computer 10 with the display unit opened. The personal computer 10 includes a computer main body 11 and a display unit 12. The display unit 12 incorporates a display device composed of an LCD (Liquid Crystal Display) 17, and the display screen of the LCD 17 is positioned substantially at the center of the display unit 12.

  The display unit 12 is attached to the computer main body 11 so as to be rotatable between an open position and a closed position. The computer main body 11 has a thin box-shaped housing to which a battery can be detachably mounted.

  On the upper surface of the computer main body 11, a keyboard 13, a power button switch 14 for turning on / off the power, a touch pad 15, and the like are arranged.

  Next, the system configuration of the personal computer 10 in the present embodiment will be described with reference to FIG.

  As shown in FIG. 2, the personal computer 10 includes a CPU 111, a north bridge 114, a main memory 115, a graphics processing unit (GPU) 116, a south bridge 117, a BIOS-ROM 120, a hard disk drive (HDD) 121, and an optical disk drive. (ODD) 122, various PCI devices 123 and 124, an embedded controller / keyboard controller IC (EC / KBC) 140, a power supply circuit 141, and the like.

  The CPU 111 is a processor provided to control the operation of the personal computer 10 and executes an operating system (OS) 200 and various application programs 202 that are loaded from the HDD 121 to the main memory 115. Further, the CPU 111 executes a display driver 201 that is software for controlling a display circuit including the GPU 116. The CPU 111 can save power by shifting the display circuit from the normal mode to the power saving mode by executing the display driver 201.

  A drawing request for two-dimensional or three-dimensional graphics from the operating system (OS) 200 or the application program 201 is sent to the GPU 116 via the display driver 201. Further, the CPU 111 also executes a system BIOS (Basic Input Output System) stored in the BIOS-ROM 120. The system BIOS is a program for hardware control.

  The CPU 111 operates in response to a clock signal supplied from the clock generator 112. By changing the frequency of the clock supplied from the clock generator 112, the CPU 111 can operate by switching to one of three operation modes, for example, a normal mode, a power saving mode, and a sleep mode. The normal mode is a mode in which the ability of the CPU 111 is maximized, and the frequency of the clock supplied to the CPU 111 is the highest, and as a result, the power consumption per unit time is maximized. On the other hand, the power saving mode is a mode in which power saving is prioritized over the capability of the CPU 111, and the frequency of the clock supplied to the CPU 111 is reduced compared to that in the normal mode. As a result, the power consumption per unit time can be suppressed. The sleep mode is a mode for further saving power than the power saving mode, and the supply of the clock to the CPU 111 is stopped.

  The north bridge 114 is a bridge device that connects the local bus of the CPU 111 and the south bridge 117. The north bridge 114 also includes a memory controller that controls access to the main memory 115. Further, the north bridge 114 has a function of executing communication with the GPU 116 via a PCI Express bus and the like, and an operation control unit 114 a that controls the frequency of the clock supplied from the clock generator 112 to the CPU 111.

The display circuit in the personal computer 10 includes a GPU 116, a VRAM 116A, an LCD 17 and the like.
The GPU 116 is a display controller that controls the LCD 17 used as a display monitor of the personal computer 10 and an external display 302 such as a CRT. The external display 302 is connected to an external video output terminal 301 provided in the computer main body 11 as necessary.

  The GPU 116 has a drawing function for displaying two-dimensional graphics and three-dimensional graphics. The GPU 116 executes display processing (graphics calculation processing) for drawing a frame group in the video memory (VRAM) 116A based on a drawing request transmitted from the CPU 111 via the north bridge 114. Specifically, when a drawing request corresponding to a certain frame is received, the GPU 116 executes various graphics calculation processes specified by the received drawing request to generate a frame including various objects, and the generated frame is displayed. Store in the VRAM 116A.

  The GPU 116 and the VRAM 116A can operate at any one of a plurality of operating frequencies. In the present embodiment, for example, it is possible to switch to one of three operating frequencies F1, F2, and F3. Control of the operating frequency of the GPU 116 and the VRAM 116A is performed by the display driver 201 (GPU operating frequency control unit 502b).

  When the display circuit is operated in the power saving mode by the power saving function processing, the power consumption is reduced by lowering the operating frequency of the GPU 116 and the VRAM 116A.

  The LCD 17 includes a backlight 17a and a drive circuit 17b that drives the backlight 17a. The drive circuit 17b is controlled by, for example, an embedded controller / keyboard controller IC (EC / KBC) 140 described later.

  The south bridge 117 is connected to the PCI bus 1 and performs communication with the PCI devices 123 and 124 via the PCI bus 1. The PCI device 123 is a communication device that transmits and receives data via a network, for example. The communication device is connected to a network by radio such as a wireless local area network (LAN), and executes downloading of a file along with execution of a browser program (application).

  The south bridge 117 incorporates an IDE (Integrated Drive Electronics) controller and a Serial ATA controller for controlling the HDD 121 and the optical disk drive (ODD) 122.

  The embedded controller / keyboard controller IC (EC / KBC) 140 is a one-chip microcomputer in which an embedded controller for power management and a keyboard controller for controlling the keyboard (KB) 13 and the touch pad 15 are integrated. . The EC / KBC 140 has a function of powering on / off the personal computer 10 in accordance with the operation of the power button switch 14 by the user. The power-on / power-off control of the personal computer 10 is executed by the joint operation of the EC / KBC 140 and the power supply circuit 141. The power supply circuit 141 generates an operation power supply for each component using power from the battery 142 attached to the computer main body 11 or power from the AC adapter 143 connected to the computer main body 11 as an external power supply. Further, the EC / KBC 140 operates as a controller that controls the luminance of the backlight 17 a under the control of the display driver 201.

  The power supply circuit 141 is provided with a power supply microcomputer 144, and power consumption in each component can be measured.

FIG. 3 shows a configuration example of the GPU 116 in the present embodiment.
As shown in FIG. 3, the GPU 116 includes a core unit 401, a low voltage differential signaling (LVDS) interface unit 402, a D / A converter (DAC) 403, a host interface (I / F) unit 404, and a control register 405. , And an internal clock generator 406 and the like.

  The core unit 401 is a unit that executes processing related to display such as display processing (graphics calculation processing) and screen refresh processing. The core unit 401 includes a 2D engine, a 3D engine, a video engine, a display engine, a VRAM interface unit, and the like. When the power saving mode is set by the control of the display driver 201, the core unit 401 can reduce the refresh rate by the screen refresh process.

  The LVDS interface unit 402 converts display data read from the VRAM 116 </ b> A by the core unit 401 into an LVDS format display signal, and supplies the LVDS format display signal to the LCD 17. The D / A converter (DAC) 403 converts the display data into an analog display signal, and supplies the analog display signal to the external display 302.

  A host interface unit (I / F) 404 receives various control parameters from the CPU 111. The various control parameters include drawing parameters, object data such as texture, and control parameters related to power management. Control parameters related to power management include clock parameters. The clock parameter is a parameter for designating the frequency of the internal clock signals CLK1 and CLK2 supplied to the core unit 401 in the GPU 116. In the present embodiment, for example, one of three operating frequencies F1, F2, and F3 is designated. The internal clock signal CLK1 is a core clock signal for driving the core unit 114, and the internal clock signal CLK2 is a memory clock signal for driving the VRAM 116A. The core clock parameter is set in the control register 405. When the GPU 116 is set to the power saving mode, it is set to, for example, the lowest operating frequency.

  The internal clock generator 406 generates internal clock signals CLK1 and CLK2 corresponding to the frequency specified by the clock parameter by multiplying or dividing the external clock signal (CLK). The internal clock generator 406 is composed of, for example, a PLL (Phase Locked Loop) circuit.

FIG. 4 is a diagram illustrating a software relationship related to the display circuit in the present embodiment.
When display processing is executed in the GPU 116, a drawing request from the application program 202 is sent to the display driver 201 via the OS 200. The display driver 201 transmits a drawing request to the GPU 116. The GPU 116 executes display processing (graphics calculation processing) in response to a drawing request from the display driver 201, generates a frame including various objects, and stores the generated frame in the video memory (VRAM) 116A.

  Further, the display driver 201 executes power saving function processing for reducing power consumption in the display circuit. The display driver 201 includes modules of a processing detection unit 501, a power saving mode setting unit 502, and an input detection unit 503 for executing power saving function processing.

  The process detection unit 501 detects that the display circuit can shift from the normal mode to the power saving mode in accordance with the process for the application program. That is, the process detection unit 501 acquires the process status for the application program through the OS 200, and determines whether the process status of the application is a status that can be shifted to the power saving mode.

  In the present embodiment, for example, when the application program is being activated, it is possible to shift to the power saving mode. The OS 200 grasps the start time and end time of the activation process for the application program. The process detection unit 501 acquires the start time and end time of the startup process of the app program via the OS 200, and detects that the transition to the power saving mode is possible while the startup process is being executed.

  In the application program startup processing, high-speed processing is required for the CPU 111, the main memory 115, the HDD 121, and the like, but processing in the display circuit including the GPU 116 is not important because no user operation is required. Therefore, even in a situation where the CPU 111 operates with the maximum capability in the normal mode, it is determined that the display circuit can be shifted to the power saving mode.

  It should be noted that the processing status capable of shifting to the power saving mode is not limited to the application program activation processing described above. For example, when downloading a file via a network, it is determined that the mode can be shifted to the power saving mode, for example, when a web page is read. The process detection unit 501 acquires, for example, a web page read start / end notification from the browser program via the OS 200, and detects that the display circuit is in a process state capable of shifting to the power saving mode.

  That is, even when the operation mode in the CPU 111 is the normal mode, the process detection unit 501 saves the display circuit while waiting for a user operation with the process for the application program. It is detected that transition to the power mode is possible. The process detection unit 501 monitors the processing status for various application programs 202 and detects whether the display circuit can be shifted to the power saving mode.

  The power saving mode setting unit 502 sets the power saving mode for the display circuit when the processing detection unit 501 detects that the display circuit can be shifted to the power saving mode. The power saving mode setting unit 502 includes a backlight control unit 502a and a GPU operating frequency control unit 502b.

  The backlight control unit 502a sets the control for the backlight 17a of the LCD 17 to the power saving mode, and saves power by reducing the luminance of the backlight 17a. The backlight control unit 502a controls the drive circuit 17b via the EC / KBC 140 so as to reduce the luminance of the backlight 17a.

  The GPU operating frequency control unit 502b sets the power saving mode by lowering the operating frequency of the GPU 116 and the driving frequency of the VRAM 116A. The GPU operating frequency control unit 502b sets a clock parameter for the GPU 116 so that the operating frequency is, for example, the lowest. Thereby, for example, the operating frequency of the clock signal of the 2D engine, 3D engine, video engine, and display engine of the core unit 401, and the memory clock signal of the VRAM 116A is reduced to save power.

  In addition, the power saving mode setting unit 502 controls the GPU 116 to lower the refresh rate by the screen refresh process.

  The input detection unit 503 detects an input operation by the user after the power saving mode setting unit 502 sets the power saving mode for the display circuit. When the input detection unit 503 detects through the OS 200 that the user has performed an input operation on the keyboard 13 or the touch pad 15, the input detection unit 503 notifies the power saving mode setting unit 502. In response to the notification from the input detection unit 503, the power saving mode setting unit 502 cancels the setting of the power saving mode for the display circuit and shifts to the normal mode.

Next, the operation in this embodiment will be described.
FIG. 5 is a flowchart showing the power saving function processing for the display circuit by the display driver 201 in this embodiment. Here, a case where the activation process of the application program 202 is detected and the display circuit is set to the power saving mode will be described as an example.

  The process detection unit 501 of the display driver 201 monitors the generation of the application program activation process through the OS 200 (step A1). The process detection unit 501 determines whether the power saving function for the display circuit is effective when notified that the application program activation process has started via the OS 200.

  When the application is created so as to display an animation or the like during the activation process, a drawing request for two-dimensional or three-dimensional graphics is issued from the application program to the OS 200. The OS 200 notifies the display driver 201 of an animation drawing request from the application.

  In this case, the process detection unit 501 determines that the power saving function is not effective because it is necessary to execute, for example, a drawing process by the 2D engine or the 3D engine in the core unit 401 (step A3, No). The display driver 201 transmits a drawing request for two-dimensional or three-dimensional graphics from the application program to the GPU 116 to execute drawing such as animation.

  On the other hand, in the case of an application program activation process that does not include a drawing request, the process detection unit 501 determines that the power saving function is valid (Yes in step A3).

  When the processing detection unit 501 detects that the power saving function is valid and the transition to the power saving mode is possible, the power saving mode setting unit 502 switches the display circuit from the normal mode to the power saving mode. Transition (step A4).

  The backlight control unit 502a performs setting for the EC / KBC 140 to reduce the luminance of the backlight 17a. The EC / KBC 140 controls the backlight 17a according to the setting by the backlight control unit 502a, and reduces the luminance of the backlight 17a.

  Further, the GPU operating frequency control unit 502b sets a clock parameter in the control register 405 so as to make the operating frequency of the GPU 116 the lowest. The internal clock generator 406 of the GPU 116 generates clock signals CLK 1 and CLK 2 specified by the clock parameter set in the control register 405 and outputs them to the core unit 401. As a result, the core unit 401 operates at a lower operating frequency, thereby reducing power consumption.

  Further, the display driver 201 instructs the GPU 116 to shift to a refresh rate lower than that in the normal mode. The GPU 116 executes a screen refresh process so that the screen is displayed at a refresh rate according to an instruction from the display driver 201. As a result, the number of times of drawing a frame on the LCD 17 is reduced, thereby reducing the power consumption.

  Thus, by shifting the display circuit to the power saving mode, it is possible to reduce power consumption in the display circuit while the application program activation process is being executed. The operation in the power saving mode in the display circuit is continued until the process detection unit 501 detects that the application program startup process has been completed.

  During this time, the input detection unit 503 monitors whether there is an input operation on the keyboard 13 or the touch pad 15 by the user. For example, an input operation on the keyboard 13 is detected by the keyboard driver 203 and notified to the OS 200. The input detection unit 503 can detect a key input to the keyboard 13 through the OS 200.

  When there is no input operation, the setting of the power saving mode for the display circuit is continued. On the other hand, when the input detection unit 503 detects that there is an input operation (step A6, Yes), it notifies the power saving mode setting unit 502. In response to the notification from the input detection unit 503, the power saving mode setting unit 502 cancels the setting of the power saving mode for the display circuit and shifts to the normal mode (step A7).

  For example, in the application program activation process, the user may not be able to confirm the display contents because the display circuit is operating in the power saving mode. For this reason, even when a failure occurs in the activation process of the application program, the operation status cannot be confirmed. Therefore, when there is a key input, the display driver 201 shifts the power saving mode for the display circuit to the normal mode so that normal display is performed on the LCD 17.

  In the above description, the keyboard 13 and the touch pad 15 are taken as an example, but any input device that performs input by a user operation such as a mouse may be used. Any input operation may be used.

  In this way, the power saving mode for the display circuit can be easily canceled by an input operation by the user, so that even if the display circuit is operated in the power saving mode and the display content on the LCD 17 becomes harder to see than usual, There will be no hindrance in the use of.

  In the above description, the personal computer 10 is described as an example, but various electronic devices can be targeted. In particular, in an electronic device with a low processing speed, even if a multitasking OS is used, for example, an operation by a user is often not performed in an application program activation process. Therefore, particularly in an electronic device with a slow processing speed, it is possible to save power by shifting the display circuit to the power saving mode in accordance with a startup process for an application program that is not operated by the user. .

  In the above description, the display driver 201 controls the luminance of the backlight 17a via the EC / KBC 140. However, if the GPU 116 is provided with a module for controlling the backlight 17a, the display driver 201 can communicate via the GPU 116. What is necessary is just to control the brightness | luminance of the backlight 17a.

  Further, the present invention is not limited to the above-described embodiments as they are, and can be embodied by modifying the constituent elements without departing from the scope of the invention in the implementation stage. In addition, various inventions can be formed by appropriately combining a plurality of components disclosed in the embodiment. For example, some components may be deleted from all the components shown in the embodiment. Furthermore, you may combine a component suitably in different embodiment.

  Further, the processing described in the above-described embodiment is a recording medium such as a magnetic disk (flexible disk, hard disk, etc.), optical disk (CD-ROM, DVD, etc.), semiconductor memory, etc., as a program that can be executed by a computer. And can be provided to various devices. It is also possible to transmit to a variety of devices by transmitting via a communication medium. The computer reads the program recorded on the recording medium or receives the program via the communication medium, and the operation is controlled by this program, thereby executing the above-described processing.

  DESCRIPTION OF SYMBOLS 10 ... Computer, 11 ... Computer main body, 17 ... LCD, 111 ... CPU, 115 ... Main memory, 116 ... GPU, 116A ... VRAM, 140 ... EC / KBC, 201 ... Display driver, 401 ... Core unit, 406 ... Internal clock Generator 501... Processing detection unit 502... Power saving mode setting unit 502 a. Backlight control unit 502 b. GPU operating frequency control unit 503.

Claims (4)

A display circuit including a GPU (Graphic Processing Unit) that operates by shifting from the first operation mode to the second operation mode for power saving;
Detecting means for detecting that the display circuit is capable of shifting to the second operation mode in accordance with the processing for the application program;
When the detection means detects that the transition to the second operation mode is possible, the display circuit is set to the second operation mode in order to lower the operation frequency of the GPU. An electronic device comprising: setting means. It further comprises input detection means for detecting that there is an input to the input device,
The setting means sets the second operation mode for the display circuit, and then detects that the input is detected by the input detection means, the first operation for the display circuit. The electronic device according to claim 1, wherein the electronic device is set to a mode. The display circuit includes a backlight,
The electronic device according to claim 2, wherein the setting unit lowers the luminance of the backlight in the second operation mode than in the first operation mode.   The electronic device according to claim 1, wherein the detection unit detects that an application is being activated.

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