JP4839936B2 - Information processing apparatus and information processing method - Google Patents

Description

  The present invention relates to an information processing apparatus capable of autonomously controlling power supply inside the apparatus and an information processing method therefor.

In recent years, in the field of computer system technology, when processing is necessary, such as when the supply of power within the device is stopped when processing is not being performed and an input operation is performed on the device, power is instantaneously generated. Power control technology has been developed that reduces power consumption during standby by resuming the supply of power.
For example, in a portable device such as a PDA (Personal Digital Assistant), when an operation is not performed for a certain period of time, the CPU operates at a low frequency and enters a low power consumption mode in which supply of power to peripheral circuits is stopped. It has been known to reduce power consumption during standby by automatically shifting to an ordinary state and performing processing when an operation is performed.

Further, in the device that autonomously controls power supply to each functional unit constituting the device, the power control unit supplies power in units of the power management domain, and the functional unit included in the power management domain Japanese Patent Application Laid-Open Publication No. 2004-228667 describes a technique for stopping power supply to the power management domain every time the operation ends.
Japanese Patent Application No. 2004-225162

  In recent years, portable information processing apparatuses have become widespread, and such information processing apparatuses are strongly required to reduce power consumption. Many portable information processing devices have an image display function. A graphics processing unit (GPU) that generates image data on a memory and a display using the generated image data. A display controller (DC) for displaying an image is provided, and the start and end of a series of processes performed by the GPU and DC are generally controlled by a CPU (Central Processing Unit).

  However, when the prior art of Patent Document 1 is applied to such a configuration, the GPU and DC constitute one powered management main, and the CPU becomes a powered management main that is separate from the powered management main. For this reason, in the prior art, it is necessary to supply power to the GPU and the DC from the generation of the image data to the completion of the image display. In addition, power must be supplied to the CPU until the image display is completed to control the operation of the GPU and DC.

The conventional technology has left room for further improvement for reducing power consumption in the above points.
SUMMARY OF THE INVENTION An object of the present invention is to further reduce labor by reducing the time for supplying power to each functional unit in an information processing apparatus and an information processing apparatus control method capable of autonomously controlling power supply. This further reduces the power consumption of the entire information processing apparatus.

  In order to solve the above problems, an information processing apparatus according to the present invention is an information processing apparatus that autonomously controls the supply of power in each functional unit constituting the apparatus, and starts processing for displaying an image. Control means for instructing, image data generation means for starting image data generation processing in response to an instruction from the control means, and image display processing for displaying an image on a medium using the image data generated by the image data generation means Image display means to be executed, control means, image data generation means, and power supply management means for controlling power supply to the image display means, wherein the image data generation means terminates the generation of image data. In addition to notifying the image display means, the image display means notifies the power supply management means of the end of the image display processing directly or indirectly. The power supply management means stops the supply of power to the control means upon receiving an instruction from the control means, and receives the notification of the end of the image display processing, and the image data generation means and the image display means The power supply is stopped.

  According to such an invention, the image data generation means notifies the end of the image data generation to the image display means, and the image display means notifies the end of the image display processing directly or indirectly to the power supply management means. Can do. Then, the power supply management means stops supplying power to the control means upon receiving an instruction from the control means, and receives the notification of completion of the image display processing and supplies power to the image data generating means and the image display means. Can be stopped.

For this reason, after the generation of image data starts, the control means does not consume power, and the information processing apparatus can be saved. Further, even if the power supply to the control unit is stopped, the power of the image data generation unit and the image display unit can be turned off without receiving control from others after the process is completed.
Such an embodiment of the present invention can further reduce the power consumption of the entire information processing apparatus by further reducing the time for supplying power to each functional unit and further saving labor.

In the information processing apparatus of the present invention, the image data generation unit notifies the image display unit of the end of image data generation, and the image display unit notifies the image data generation unit of the end of image display processing. Then, the end of the image display processing is notified to the power supply management means via the image data generation means.
According to such an invention, the image display means can notify the end timing of the image display processing to the image data generation means. For this reason, after the image data generating means transfers the image data to the image display means, other processing can be executed, and the processing efficiency of the information processing apparatus can be further enhanced.

  The control method of the information processing apparatus according to the present invention includes a control unit that instructs the start of a process for displaying an image, an image data generation unit that starts an image data generation process according to an instruction from the control unit, A method of controlling an information processing apparatus, comprising: an image display unit that executes an image display process for displaying an image on a medium using image data generated by the unit, and starts a process for displaying an image A start instruction signal to be instructed is input to start power supply to the image data generation unit, and to stop power supply to the control unit, and to start power supply by the first control step. An end signal for notifying the end of image display based on the image data generated by the image data generation means is input, and the image data generation Stage, characterized in that it comprises a second power control step of stopping the supply of power to said image display means.

According to such an invention, after the generation of the image data is started, the control unit does not consume power, and the information processing apparatus can be saved. Further, even if the power supply to the control unit is stopped, the power of the image data generation unit and the image display unit can be turned off without receiving control from others after the process is completed.
Such an embodiment of the present invention can further reduce the power consumption of the entire information processing apparatus by further reducing the time for supplying power to each functional unit and further saving labor.

Embodiments 1 and 2 of an information processing apparatus according to the present invention will be described below with reference to the drawings.
(Embodiment 1)
FIG. 1 is a diagram for explaining the information processing apparatus according to the first embodiment of the present invention. The illustrated information processing apparatus is an information processing apparatus that autonomously controls the supply of power in each functional unit constituting the apparatus. The information processing apparatus according to the first embodiment has a function of displaying an image based on data acquired through a data recording medium such as a memory card or a communication line. Then, a CPU (Central Processing Unit) 101 that instructs the start of processing for displaying an image, a GPU (Graphics Processing Unit) 105 that generates image data for displaying an image according to an instruction from the CPU 101, and a GPU 105 A DC (display controller) 106 that executes image display processing for displaying an image on a display medium using image data, a power management circuit (hereinafter referred to as PM) 102 that controls supply of power to the CPU 101, GPU 105, and DC 106. Including.

  In the first embodiment, the GPU 105 notifies the end of image data generation to the DC 106, and the DC 106 notifies the end of the image display process directly or indirectly to the PM 102. Then, the PM 102 stops supplying power to the CPU 101 upon receiving an instruction from the CPU 101, and stops supplying power to the GPU 105 and the DC 106 upon receiving notification of the end of the image display processing.

In the above configuration, the CPU 101 functions as control means, the GPU 105 functions as image data generation means, the DC 106 functions as image display means, and the PM 102 functions as power supply management means.
The GPU 105 is hardware that performs processing for generating an image to be displayed on the display 107 on, for example, the memory 104 at high speed while reading a command prepared by the CPU 101 on the memory 104. Specifically, the GPU 105 performs a drawing process in which a vector graphic drawing command prepared by the CPU 101 on the memory 104 is expanded into a raster graphic.

  In addition, the DC 106 outputs image data for displaying on the display 107 the graphic on which the GPU 105 has performed the drawing process. At this time, the DC 106 can send the image data directly to the display 107, but can also send the drawing data once stored in the memory 104. In this case, the image data stored in the memory 104 can be reused later.

  Furthermore, the information processing apparatus according to the first embodiment includes a memory 104 that stores programs, data, and the like used for control of the CPU 101, and is connected to the peripheral device 103. The DC 106 displays an image on the display 107 which is a display medium. The display 107 is a thin so-called electronic paper display using a memory liquid crystal. The memory 104 includes a ROM (Read Only Memory) and an NVRAM (NonVolatile RAM), and the ROM and the nonvolatile NVRAM are selectively used depending on the type of information to be stored. The peripheral device 103 may be, for example, a memory card controller or a communication controller.

The PM 102 controls the power supply as a unit (power management domain) for receiving each power supply (indicated as a functional unit) such as the CPU 101, the GPU 105, and the DC 106 described above as an independent power supply. The PM 102 is connected to each power management domain by a power supply line for supplying power.
In the first embodiment, the CPU 101 configures one power management domain, and the GPU 105 and the DC 106 configure one power management domain or separate power management domains. Good.

Each functional unit is connected by a control signal line necessary for power control, such as a clock control line and a reset release signal. Furthermore, the functional units are connected by a bus and can exchange data necessary for image processing.
In the information processing apparatus according to the first embodiment, the GPU 105 can directly output a signal to the DC 106 without using a bus. In the first embodiment, this signal is referred to as a DCGO signal. The DCGO signal is a signal for the GPU 105 to notify the end of image data generation and instruct the DC 106 to start activation.

  Next, the operation of the information processing apparatus according to the first embodiment configured as described above will be described. FIG. 2 is a flowchart for explaining processing executed in advance before the GPU 105 is activated in the first embodiment. In the flowchart shown in FIG. 2, the PM 102 detects the start of electronic paper operation when the operator operates the button on the display 107, connects a communication cable to the display 107, or connects a memory card (step S1). Then, power is supplied to the power domain including the CPU 101 (step S2).

  Further, the CPU 101 starts execution of the OS and application program stored in the memory 104, and secures a predetermined area of the memory 104 as a work memory (step S3). And an event notification signal is acquired from PM102 (step S4), and the content of the event which generate | occur | produced is determined (step S5).

If it is determined in step S5 that the event that has occurred is an input operation for any button, the CPU 101 determines the type of the button that has been input (step S6).
If it is determined in step S6 that the page return button 4 has been input, the CPU 101 acquires the page number currently being browsed from the memory 104 (step S7), and subtracts “1” from the page number and is currently browsing. The page is returned by one page (step S8).

If it is determined in step S6 that the page turning button 5 has been input, the CPU 101 acquires the page number currently being viewed from the memory 104 (step S9), adds "1" to the page number, The page being browsed is advanced by one page (step S10).
After step S8 and step S10, the PM 102 supplies power to the peripheral circuit domain including the memory card controller (step S11), and reads the data of the page currently being browsed from the memory card (step S12).

Next, the PM 102 stops supplying power to the peripheral circuit domain including the memory card controller (step S13), and shifts to a recording mode in which the drawing command issued by the CPU 101 is recorded in the memory 104 (step S14). Then, a command issued by the CPU 101 to draw the page currently being browsed is recorded in the memory 104 (step S15), and then returned to an API (Application Program Interface) mode in which the drawing commands issued by the CPU 101 are sequentially executed. (Step S16).
According to the above flowchart, in the information processing apparatus according to the first embodiment, the power of the CPU 101 is turned on (step S2), and the generation of the drawing command by the CPU 101 and the recording of the generated drawing command in the memory 104 are finished. Shall.

After execution of the flowchart illustrated in FIG. 2, the information processing apparatus according to the first embodiment supplies power to the GPU 105 and the DC 106 and sets parameters necessary for each process.
The timing chart of FIG. 3 is a diagram showing the timing when each of the function units of the CPU 101, GPU 105, and DC 106 shown on the left side in the figure is turned on and off, and the end point from the start point of the arrow line is turned off from the function unit on. Is shown. The numbers shown in the arrows are numbers for explaining the timing between on and off.

  The parameter setting is executed as follows. That is, the CPU 101 starts power supply to the GPU 105 and the DC 106 (timing 1). Then, the CPU 101 writes a storage location (GPU parameter) of a rendering command necessary for generating image data in the memory 104 to the GPU 105 (timing 2). Next, the CPU 101 writes a storage location (DC parameter) of image data necessary for image display in the memory 104 to the DC 106 (timing 3). Thereafter, the CPU 101 outputs a start instruction signal instructing the GPU 105 to start processing for generating an image (timing 4). In response to an instruction from the CPU 101, the GPU 105 starts a process of generating image data in accordance with a drawing command stored in the memory 104 (timing 5).

At this time, the CPU 101 sends a power supply stop command instructing the PM 102 to stop power supply to the own device, and the CPU 101 stops when the PM 102 stops supplying power to the CPU 101 (timing 6).
With the above processing, the first embodiment does not need to supply power to the CPU 101 after the GPU 105 starts operating. For this reason, the energization time to the CPU 101 can be shortened and the entire information processing apparatus can be saved. Further, since the CPU 101 does not need to control the GPU 105 and the DC 106, the CPU 101 can be used for other processes while the GPU 105 and the DC 106 are operating. In this case, although the CPU 101 cannot be saved, another effect that the CPU can be used effectively can be obtained.

  When the processing of the GPU 105 ends (timing 7), the GPU 105 outputs a DCGO signal to the DC 106, and instructs the start of display processing operation (timing 8). The DC 106 reads out the image data from the storage location (DC parameter) of the image data necessary for displaying the image, which is set in advance at the timing 3, and starts executing the image display process for displaying on the display 107 (timing 9) .

When the image display process ends (timing 10), the DC 106 outputs a DCDONE signal notifying the PM 102 of the end (timing 11). When the DCDONE signal is input, the PM 102 stops supplying power to the GPU 105 and the DC 106 (timing 12).
Through the above processing, the first embodiment can start the operation of the DC 106 at an appropriate timing without being controlled by the CPU 101, and can stop the power supply to the GPU 105 and the DC 106 at an appropriate timing.

  In the first embodiment described above, the GPU 105 can instruct the DC 106 to specify an appropriate operation start timing. For this reason, it is not necessary for the CPU 101 to instruct the DC 106 to start operation, and the power supply to the CPU 101 can be stopped after the operation of the GPU 105 is started. Therefore, the first embodiment can save the information processing apparatus by reducing the power consumption of the CPU 101.

(Embodiment 2)
Next, Embodiment 2 of the information processing apparatus of the present invention will be described. FIG. 4 is a diagram for explaining the information processing apparatus according to the second embodiment of the present invention. The illustrated information processing apparatus has the same configuration as that of the information processing apparatus according to the first embodiment, and the same configuration is denoted by the same reference numeral and a part thereof is omitted.

  The information processing apparatus according to the second embodiment includes the same functional unit as that of the first embodiment, and is different only in a method for transmitting and receiving signals between the functional units. In the information processing apparatus according to the second embodiment, the GPU 105 notifies the end of image data generation to the DC 106, and the DC 106 notifies the GPU 105 of the end of the image display process and notifies the PM 102 of the end of the image display process via the GPU 105. To do.

  That is, in the information processing apparatus according to the second embodiment, the DC 106 directly outputs the DCDONE signal to the PM 102 at the end of the image display in the first embodiment, whereas the DC 106 transmits the DCDONE signal to the GPU 105 and the GPU 105 receives the DCDONE signal. Is input, PM 102 is notified of the end of the image display process. A signal for the GPU 105 to notify the PM 102 of the end of the image display process is referred to as a GPUDONE signal in the second embodiment.

Such an information processing apparatus according to the second embodiment is configured such that a DCGO signal and a DCDONE signal can be exchanged between the GPU 105 and the DC 106 without passing through a bus. Further, the GPU 105 is configured to be able to output a GPUDONE signal to the PM 102 without going through the bus.
Hereinafter, power supply control for the information processing apparatus according to the second embodiment will be described. The second embodiment is different from the first embodiment in the signals exchanged between the functional units, but the power control is performed in the same manner as in the first embodiment. Therefore, also in the second embodiment, the power control of the second embodiment will be described with reference to FIG. 3 described above.

  The information processing apparatus according to the second embodiment operates in the same manner as in the first embodiment from timing 1 to timing 6. That is, the GPU 105 and the DC 106 are turned on to set GPU parameters and DC parameters. Then, the CPU 101 writes a drawing start command to the GPU 105, and the GPU 105 starts generating image data. Thereafter, the CPU 101 sends a power stop command to stop power supply to the own domain to the PM 102, and the CPU 101 stops when the PM 102 stops supplying power to the CPU 101.

When the image data generation process of the GPU 105 is completed at timing 7, the GPU 105 outputs a DCGO signal to the DC 106 and instructs the display operation start (timing 8). The DC 106 executes image display processing for displaying the image data stored in the memory 104 on the display 107 (timing 9).
After the image display process is completed (timing 10), the DC 106 outputs a DCDONE signal that notifies the GPU 105 of the termination (timing 11). When the DCDONE signal is input, the GPU 105 outputs the GPUDONE signal to the PM 102. Due to the input of the GPUDONE signal, the PM 102 stops the power supply to the GPU 105 and the DC 106 (timing 12).

With the above processing, the second embodiment can stop power supply to the CPU 101 after the operation of the GPU 105 is started. Therefore, the second embodiment can save the information processing apparatus by reducing the power consumption of the CPU 101.
In the second embodiment, the GPU 105 receives the notification of the end of the image display process and requests the PM 102 to stop power supply. Therefore, the GPU 105 itself can control the power supply stop to the GPU 105. For this reason, even if other processing is executed after the GPU 105 outputs DCGO, there is no problem that the power supply is stopped during the execution of the processing.

Therefore, the configuration of the second embodiment can further increase the usage efficiency of the information processing apparatus by using the GPU 105 for other processing.
In the second embodiment, the GPU 105 can be put into a standby state from the output of the DCGO signal to the input of the DCDONE signal. Since the power consumption of the GPU 105 can be suppressed during the standby state, the second embodiment can reduce the power consumption of the GPU 105 even when other processing is not performed.

Note that suppressing the power consumption of the GPU 105 is an effective means for saving the information processing apparatus because the GPU 105 consumes a large amount of power in a device having an image display function.
In the second embodiment, the GPU 105 can operate again after the image display of the DC 106 is completed. Such an operation of the GPU 105 can be realized, for example, by inserting a step of executing a command for generating image data of another page after step S15 of FIG. If image data for one page ahead is generated in advance, the response speed of the information processing apparatus for the next user operation can be improved.

  In the second embodiment, steps for generating image data of another page and executing a display command by the DC 106 for this data can be inserted after step S15 of FIG. In this case, Embodiment 2 can perform drawing and display for two pages collectively in a display system having two display bodies. In addition, since the image processing device controlled by the CPU 101 is only the GPU 105, software development of the CPU 101 is facilitated. Further, even when the DC 106 is integrated into the GPU 105 in the future, there is an advantage that the system design and the software design need not be changed.

It is a figure for demonstrating the information processing apparatus of Embodiment 1 of this invention. 3 is a flowchart for explaining processing executed before the CPU shown in FIG. 1 starts operation in Embodiment 1 of the present invention. It is a figure for demonstrating control of the electric power supply in the information processing apparatus of Embodiment 1 of this invention. It is a figure for demonstrating the information processing apparatus of Embodiment 2 of this invention.

Explanation of symbols

101 CPU, 102 PM, 103 peripheral device, 104 memory, 105 GPU, 106 DC, 107 display

Claims (2)

An information processing apparatus that autonomously controls the supply of power in each functional unit constituting the apparatus,
Control means for instructing the start of processing for displaying an image;
Image data generation means for starting image data generation processing in accordance with an instruction from the control means;
Image display means for executing image display processing for displaying an image on a medium using the image data generated by the image data generation means;
Power supply management means for controlling power supply to the control means, the image data generation means, and the image display means;
Including
After the control means notifies the image data generation means of an image drawing start command, the power supply management means is instructed to stop power supply to the control means, and the image data generation means the end notifies the image display means, said image display means to signal the end of the images display process on the image data generating means, the image data generating means instructs to stop power supply for the power supply management unit and, the power supply management unit, the power supply to said control means stops by receiving the instruction of the power supply stop of said control means, and receives an instruction of the power supply stop from the image data generating means An information processing apparatus, wherein supply of power to the image data generation unit and the image display unit is stopped. Control means for instructing start of processing for displaying an image, image data generation means for starting image data generation processing in response to an instruction from the control means, and an image using the image data generated by the image data generation means as a medium An information processing apparatus control method comprising image display means for executing an image display process to be displayed above,
A start instruction signal for instructing the start of processing for displaying an image is input, and supply of power to the image data generation unit is started, and supply of power to the control unit is stopped according to an instruction from the control unit A first power control step;
From the image data generation means that has started power supply in the first control step, an end signal for notifying the end of image display based on the image data generated by the image data generation means is input, and the image data generation means, A second power control step of stopping the supply of power to the image display means;
The method of information processing apparatus comprising a.

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