JP2006072991A - Power-saving processing unit, power-saving processing method and power-saving processing program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To realize proper mode switching by taking into account power consumption as well in a shift processing and a return processing for switching an operation mode. <P>SOLUTION: In a power consumption information table 170, there are recorded the power consumption (mJ) which is required for a processing for shifting into a power-saving mode, consumed power (mW) when an operation is executed in the power-saving mode and the power consumption (mJ) which is required for a processing for returning to an ordinary mode. A time prediction section 102 refers to a timer list management queue 201 and predicts a period of time until the power-saving mode is removed. On the basis of the power consumption information table 170 and the predicted time, a mode switching decision section 103 compares the power consumption (mJ) between the case that switching is performed into the power saving mode and the case that switching is not performed, and only if the former is far less than the latter, decides that switching should be executed into the power-saving mode. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a power saving processing technique, and more particularly to an improvement for enhancing a power saving effect.

As a technology to reduce the power consumption of electrical equipment, power consumption is reduced by lowering the frequency of the clock supplied to the CPU, memory, or each device constituting the electrical equipment, or by lowering the voltage supplied to them. Technology to suppress this is known. There is also known a technique for suppressing power consumption by suppressing power supplied to them or by stopping power supply. These power consumption reduction processes are implemented when the target device elements (CPU, memory, devices, etc.) are not currently used, or when they can be operated with low power even when they are in use. (For example, when a program being processed by the CPU is in an idle state). In addition, after setting multiple power saving modes including power control of peripheral devices, monitor the usage status of the execution application and peripheral devices, select the power saving mode that can be taken according to the usage status, A technique for suppressing appropriate power consumption is known (see, for example, Patent Document 1).
Japanese Patent Laid-Open No. 11-73255

  However, in order to lower the clock frequency, lower the voltage, or stop the power supply, a predetermined process must be performed based on the specifications of the target device element. In addition, when power supply is stopped, a certain period may be required to stabilize the operation. That is, in order to suppress power consumption, a predetermined process is required, and power consumption due to this process occurs. The power consumption depends on the device element that performs processing for power saving. However, when processing for power saving is performed on a large number of devices, the processing for power saving is performed on a small number of device elements. Compared with the case of performing more power consumption. However, there is a relationship that the power consumption during the period of operation in the power saving mode is generally smaller when a power saving process is performed on a large number of device elements.

  In the conventional technique, the power consumption required for the power saving process for each device element as described above is not considered. As a result, the conventional technology, despite switching to the power saving mode in order to reduce the power consumption, conversely increases the power consumption, or the processing is almost unchanged. Increasing the amount has a problem that the performance of the device may be deteriorated, for example, a response delay may be caused.

  For example, there is a case where the electric device is immediately returned to the normal mode because it is requested to operate in the normal mode while switching its own operation mode to the power saving mode. Furthermore, when the electrical equipment has returned to the normal mode in a short time after shifting to the power saving mode, the operation time in the power saving mode is not sufficiently long, and the processing for power saving accounts for a large percentage. was there. In such a case, switching to the power saving mode results in an increase in power consumption.

  The present invention has been made in view of the above-described problems, and a power saving processing apparatus and power saving for realizing appropriate mode switching that also considers power consumption associated with transition processing and return processing for switching operation modes. It is an object to provide a processing method and a power saving processing program.

  In order to solve the above-described problems and achieve the above-described object, the first aspect of the present invention is to save the operation mode of the target device between a normal mode and a plurality of modes including one or more power-saving modes. A power consumption information management unit that manages information related to the switching process of the operation mode, and a switching request when a switching request from the current mode of the plurality of modes to another mode occurs. A time prediction unit that predicts a time until the other mode is canceled or a time until the current mode is restored when the request is satisfied, and the information managed by the power consumption information management unit. Based on the management information and the predicted time that is the time predicted by the time prediction unit, a period during which the other mode continues is calculated, and the calculated value is used to set the operation mode to the current mode. A mode switching determining unit for determining from the mode of whether to switch to the different modes, according to the determination of the mode switching determining unit, and a, a mode switching execution unit for switching the operation mode of the target device.

  The management information includes the processing time required for the transition processing from the current mode to each of the other modes, and the processing time required for the return processing from each of the other modes to the current mode. According to the predicted time for each mode, information that can derive a period in which each of the other modes continues is included.

  According to this configuration, when a request for switching from the current mode to another mode occurs, it is determined whether or not to switch to the requested other mode based on the management information and the predicted time. . In the determination, a time period derived from the management information and the prediction information and continuing the transition destination mode is used. For example, it is determined that the operation mode is not switched when the period during which the transition destination mode continues does not meet some criteria. Thereby, when the disadvantage by the power consumption accompanying a transfer process or a return process cannot be disregarded, switching can be withheld. As described above, according to this configuration, it is possible to realize appropriate mode switching in consideration of the power consumption associated with the transition process and the return process for switching the operation mode.

  “Management of information” means to maintain the information in a state where it can be used in accordance with the purpose, such as securing or holding the information, and changing the information if necessary. means.

  According to a second aspect of the present invention, there is provided a power saving processing apparatus according to the first aspect, wherein the one or more power saving modes are two or more power saving modes.

  According to this configuration, since the one or more power saving modes are two or more power saving modes, the operation mode can be switched between the normal mode and the two or more power saving modes.

  According to a third aspect of the present invention, there is provided a power saving processing device for switching an operation mode of a target device between a normal mode and a plurality of modes including two or more power saving modes, wherein the operation mode switching process is performed. When a request for switching from a current mode of the plurality of modes to a mode within a specific range including two or more other modes is generated, the power consumption information management unit that manages information related to A time prediction unit that predicts, for each mode in the specific range, a time until each mode in the specific range is released or a time until the current mode is restored, and the power consumption information management Based on the management information that is the information managed by the unit and the predicted time that is the time for each mode predicted by the time prediction unit, the period in which each mode within the specific range continues is calculated. And using the calculated value, a mode switching determination unit that determines a switching destination of the current mode from among the modes within the specific range, and the operation mode of the target device according to the determination of the mode switching determination unit And a mode switching execution unit for switching between.

  The management information includes the processing time required for the transition process from the current mode to another mode and the processing time required for the return process from the different mode to the current mode. According to the predicted time for a mode, information that can derive a period during which each of the other modes continues is included.

  According to this configuration, for example, when a request for switching to a mode within a specific range such as two or more power saving modes is generated, it is determined which mode within the specific range is to be switched based on the management information and the predicted time. Is done. In the determination, a period in which each mode of the transition destination is derived from the management information and the prediction information is used. For example, the longest period in which each mode of the transition destination continues is determined as the switching destination. Accordingly, the operation mode transition destination is set so that the power consumption saving effect is the highest and the disadvantage due to the power consumption associated with the transition process and the return process is minimized. As described above, according to this configuration, it is possible to realize appropriate mode switching in consideration of the power consumption associated with the transition process and the return process for switching the operation mode.

  Note that the specific range may be various ranges such as a range of all power saving modes except the current mode, a part thereof, or a range including the normal mode. Further, the specific range includes ranges of all modes other than the current mode, that is, ranges not specified.

  According to a fourth aspect of the present invention, there is provided a power saving processing apparatus for switching an operation mode of a target apparatus between a normal mode and a plurality of modes including two or more power saving modes, wherein the operation mode switching process is performed. When a request for switching from a current mode of the plurality of modes to a mode within a specific range including two or more other modes is generated, the power consumption information management unit that manages information related to A time prediction unit that predicts, for each mode in the specific range, a time until each mode in the specific range is released or a time until the current mode is restored, and the power consumption information management Based on the management information that is the information managed by the unit and the predicted time that is the time for each mode predicted by the time prediction unit, the period in which each mode within the specific range continues is calculated. And using the calculated value, a mode switching determination unit that determines whether to switch the operation mode from the current mode to any mode within the specific range, or not to switch to any mode, and the mode switching A mode switching execution unit that switches the operation mode of the target device according to the determination of the determination unit.

  The management information includes the processing time required for the transition process from the current mode to another mode and the processing time required for the return process from the different mode to the current mode. According to the predicted time for a mode, information that can derive a period during which each of the other modes continues is included.

  According to this configuration, for example, when a request for switching to a mode within a specific range such as two or more power saving modes is generated, the mode is switched to any mode within the specific range based on the management information and the predicted time, or It is determined whether to switch to any mode. In the determination, a period in which each mode of the transition destination is derived from the management information and the prediction information is used. For example, the longest period during which each mode of the transfer destination continues is determined as a transfer destination candidate. Furthermore, for example, when the period during which the transition destination mode as the candidate continues does not meet some criteria, it is determined that the operation mode is not switched. As a result, the transition destination of the operation mode is set so that the effect of sufficiently saving the power consumption is the highest, and the disadvantage due to the power consumption associated with the transition process and the return process is minimized, and any transition destination Regarding the mode, when the disadvantage caused by the switching of the operation mode cannot be ignored, the switching can be withheld. As described above, according to this configuration, it is possible to realize appropriate mode switching in consideration of the power consumption associated with the transition process and the return process for switching the operation mode. The specific range is as described above.

  According to a fifth aspect of the present invention, there is provided a power saving processing device according to any one of the first to fourth aspects, wherein the switching request is the normal mode as the current mode. It includes a switching request.

  According to this configuration, since the switching request includes a switching request when the current mode is the normal mode, when there is a switching request from the normal mode, the transition process and the return process for switching the operation mode are performed. Appropriate mode switching in consideration of the accompanying power consumption is realized.

  According to a sixth aspect of the present invention, there is provided a power saving processing device according to any one of the second to fourth aspects, wherein the switching request is the normal mode as the current mode. A switching request, and a switching request when the current mode is one of the two or more power saving modes.

  According to this configuration, since the switching request includes the switching request when the current mode is the normal mode and the switching request when the current mode is one power saving mode, there is a switching request from the normal mode. In addition, when there is a switching request from a certain power saving mode, appropriate mode switching is realized in consideration of the power consumption associated with the transition process and the return process for switching the operation mode.

  According to a seventh aspect of the present invention, there is provided a power saving processing device according to any one of the first to sixth aspects, wherein the mode switching determination unit is configured to extend a period during which the other mode continues. The determination is performed by evaluating the thickness.

  According to this configuration, the mode switching determination unit determines the mode as the transition destination or the mode as the transition destination candidate by evaluating the length of the period in which the mode continues. For example, the mode switching determination unit determines that the operation mode is switched only when the length of the period is a positive number, or selects the operation mode with the longest period as the transition destination. Or For this reason, a determination result is obtained by simple processing.

  According to an eighth aspect of the present invention, there is provided a power saving processing device according to any one of the first to sixth aspects, wherein the mode switching determination unit performs the transition process to the different mode. The determination is made by evaluating the power consumption as the sum of the power consumption required, the power consumption required for the period during which the other mode continues, and the power consumption required for the return processing to the current mode. The management information includes the power consumption of the target device in each of the other modes, the power consumption of the target device required for the transition process from the current mode to each of the other modes, and the current Power consumption of the target device required for the process of transition from one mode to the other mode, the processing time required for the transition process from the current mode to the other mode, and the current mode from the other mode No Power consumption of the target device required for return processing to the current mode, power consumption of the target device required for return processing from the different modes to the current mode, and current mode from the different modes. Among the processing time required for the return processing to the mode, the mode switching determination unit includes information that can derive the power consumption to be evaluated based on the predicted time for each mode. .

  According to this configuration, the determination is performed by evaluating the power consumption by switching the operation mode in consideration of the power consumption accompanying the transition process and the return process. For example, only when the operation mode with the lowest power consumption is selected as the transition destination or when the power consumption is lower than the power consumption in the current operation mode, a determination is made to change the mode. . Thereby, it is possible to obtain a more accurate determination that directly takes into account the power consumption associated with the transition process and the return process. As a result, more appropriate mode switching is realized.

  In calculating the power consumption required for the period in which another mode continues, the power consumption of the target device in another mode included in the management information is multiplied by the period in which the other mode continues, thereby It is necessary to calculate the power consumption. That is, in this configuration, the mode switching determination unit calculates a period during which another mode continues, and uses the calculated value for calculation of power consumption during the period. As for the relationship between the power consumption and the power consumption, the power consumption per unit time corresponds to the power consumption. That is, the power consumption corresponds to the time integration amount of power consumption.

  According to a ninth aspect of the present invention, there is provided a power saving processing device according to the first or second aspect, wherein the mode switching determination unit consumes power required for the transition process to the different mode. Power consumption as the sum of the power consumption required for the period during which the other mode continues and the power consumption required for the return processing to the current mode, and the power consumption of the current mode during the same period The management information includes the power consumption of the target device in the current mode, the power consumption of the target device in each of the other modes, and the current Power consumption of the target device required for the transition processing from each mode to the other mode, power consumption of the target device required for the transition processing from the current mode to each other mode, and the current A processing time required for a transition process from a mode to each of the other modes, a power consumption of the target device required for a return process from the other modes to the current mode, and Based on the predicted time for each mode among the power consumption of the target device required for the return process to the current mode and the processing time required for the return process from the other mode to the current mode. The mode switching determination unit includes information that can derive the power consumption to be compared.

  According to this configuration, based on a comparison between the power consumption by switching the operation mode in consideration of the power consumption associated with the transition process and the return process, and the power consumption when the operation mode is not switched. The determination is made. Thereby, it is possible to obtain a more accurate determination that directly takes into account the power consumption associated with the transition process and the return process. As a result, more appropriate mode switching is realized.

  Similar to the configuration according to the eighth aspect, also in this configuration, the mode switching determination unit calculates a period in which another mode continues, and uses the calculated value for calculating the power consumption amount in the period. The relationship between power consumption and power consumption is also as described above.

  According to a tenth aspect of the present invention, there is provided a power saving processing device according to any one of the first to ninth aspects, further comprising a timer event management unit for managing a timer event, wherein the time prediction unit Is the time until the transition destination mode is canceled based on the time when the timer event is executed by searching for the timer event managed by the timer event management unit. It has a timer event prediction unit for prediction.

  According to this configuration, since the timer event prediction unit is provided, the time at which the timer event is executed is reflected in the prediction time that is the basis of the determination by the mode switching determination unit. Thereby, more accurate determination can be easily realized.

  According to an eleventh aspect of the present invention, there is provided a power saving processing device according to the tenth aspect, wherein the timer event management unit uses or does not use a component part of the target device that accompanies execution of a timer event. Device usage information indicating use is also managed for each timer event, and the management information managed by the power consumption information management unit is used or not used in the constituent parts of the target device in each power saving mode. The timer event prediction unit refers to the device usage information and the device selection information, and the timer event prediction unit is configured to perform prediction of the timer events managed by the timer event management unit. Based on the execution time of the timer event in which the component part of the target device that is not used in the target transfer destination mode is used first, the transfer destination Is intended to predict the time until over de is released.

  According to this configuration, the timer event prediction unit refers to the device usage information and the device selection information, so that, in the timer event managed by the timer event management unit, in the transition destination mode to be predicted. Based on the execution time of the timer event that is used first by the component part of the target device that is not used, the time until the transition destination mode is released is predicted, so each timer event and the transition destination mode A more accurate prediction time can be obtained considering the use / non-use state of the device.

  According to a twelfth aspect of the present invention, there is provided a power saving processing apparatus according to any one of the first to eleventh aspects, wherein the time prediction unit is one or more types of repetitive occurrences that occurred in the past. It has a repetitive interrupt prediction unit that predicts the time until the transition destination mode is canceled or the time until the current mode is restored based on the time interval of each interrupt. Is.

  According to this configuration, since the iterative interrupt prediction unit is provided, the time when the repetitive interruption occurs is reflected in the prediction time that is the basis of the determination by the mode switching determination unit based on the past results. Thereby, more accurate determination is realized. Note that the time prediction unit can have both a timer event prediction unit and a repetitive interrupt prediction unit, thereby obtaining a prediction time considering both the timer event and the repetitive interrupt.

  According to a thirteenth aspect of the present invention, there is provided a power saving processing device according to the twelfth aspect, wherein the repetitive interrupt predicting unit is configured so that each of the one or more types of repetitive interrupts generated in the past is performed. A measurement unit that calculates an average value of the time intervals of the above, and based on each of the average values, the time until the transition destination mode is canceled or the current mode that is the target of the prediction It predicts the time to return.

  According to this configuration, the predicted time can be obtained based on the average value of the time intervals of each repetitive interrupt that has occurred in the past, so that a predicted time with high accuracy can be obtained.

  According to a fourteenth aspect of the present invention, there is provided a power saving processing apparatus according to the twelfth aspect, wherein the repetitive interrupt predicting unit is configured so that each of the one or more types of repetitive interrupts generated in the past is performed. A measurement unit that calculates a latest time interval that is the latest time interval of the first time interval, and based on each of the latest time intervals, a time until the transition destination mode is released, which is a target of the prediction, or The time until returning to the current mode is predicted.

  According to this configuration, since the predicted time can be obtained based on the time interval of each repetitive interrupt that has occurred in the latest past, the predicted time can be obtained by a simple calculation.

  According to a fifteenth aspect of the present invention, there is provided a power saving processing apparatus according to any one of the twelfth to fourteenth aspects, wherein the time prediction unit is configured to generate the one or more repetitive interrupts generated in the past. Managing device usage information indicating use or non-use of a component of the target device associated with each execution of the management information, and the management information managed by the power consumption information management unit is the target device in each power saving mode. Device selection information indicating what is used or not used among the constituent parts of, and the iterative interrupt prediction unit refers to the device usage information and the device selection information, and has occurred in the past Based on the time interval of the repetitive interrupt in which the component part of the target device that is not used in the destination mode to be predicted is used among one or more types of repetitive interrupts, the transition Time or the up mode is canceled is to predict the time to return to the current mode.

  According to this configuration, the iterative interrupt prediction unit refers to the device usage information and the device selection information, and is not used in the transition destination mode to be predicted among the repetitive interrupts generated in the past. Since the estimated time is obtained based on the time interval of the repetitive interrupt in which the component part of the target device is used, the use / non-use state of the device in each repetitive interrupt and the destination mode is also considered A more precise prediction time can be obtained.

  According to a sixteenth aspect of the present invention, there is provided a power saving processing device according to any one of the first to fifteenth aspects, wherein the power saving processing device is included in the target device and includes itself. This is a target for switching the operation mode.

  According to this configuration, since the power saving processing device is also subject to the operation mode switching as a part of the target device, more effective power saving processing is realized.

  According to a seventeenth aspect of the present invention, there is provided a power saving processing apparatus according to any one of the first to sixteenth aspects, wherein the power saving processing apparatus is built on a single semiconductor substrate. It is formed as a semiconductor integrated circuit.

  According to this configuration, since the power saving processing apparatus of the present invention is formed on a single semiconductor substrate, the power saving processing apparatus of the present invention can be used in a compact manner. Therefore, this configuration is suitable for use in a mobile communication terminal such as a mobile phone.

  According to an eighteenth aspect of the present invention, there is provided a power saving processing method for switching an operation mode of a target device between a normal mode and a plurality of modes including one or more power saving modes, wherein the operation mode switching processing is performed. When a request for switching from the current mode of the plurality of modes to another mode is generated, the other mode is canceled when the request for switching is received. A time prediction step for predicting a time until the current mode is returned or a time for returning to the current mode, management information that is the information managed by the power consumption information management step, and the time predicted by the time prediction step. A mode switching determination step for determining whether to switch the operation mode from the current mode to the other mode based on a certain prediction time; and the mode switching According to the judgment of a constant step, and a, a power-saving mode execution step of switching the operation mode of the target device.

  The management information includes the processing time required for the transition processing from the current mode to each of the other modes, and the processing time required for the return processing from each of the other modes to the current mode. According to the predicted time for each mode, information that can derive a period in which each of the other modes continues is included.

  According to this configuration, for the same reason as described for the power saving device according to the first aspect of the present invention, appropriate mode switching that also considers the power consumption associated with the transition process and the return process for switching the operation mode Is realized.

  According to a nineteenth aspect of the present invention, there is provided a power saving processing program for causing a computer to function as a power saving processing device that switches an operation mode of a target device between a normal mode and a plurality of modes including one or more power saving modes. And a power consumption information management means for managing information related to the switching process of the operation mode, and when a switching request from the current mode to another mode of the plurality of modes is generated, the switching request is responded to A time prediction unit that predicts a time until the other mode is canceled or a time until the current mode is restored, management information that is the information managed by the power consumption information management unit, and Whether to switch the operation mode from the current mode to the other mode based on the predicted time which is the time predicted by the time prediction means A mode switching determining means for determining, according to the determination of the mode changeover judging part, causes the computer to function as the power saving mode executing means for switching the operation mode of the target device.

  The management information includes the processing time required for the transition processing from the current mode to each of the other modes, and the processing time required for the return processing from each of the other modes to the current mode. According to the predicted time for each mode, information that can derive a period in which each of the other modes continues is included.

  According to this configuration, for the same reason as described for the power saving device according to the first aspect of the present invention, appropriate mode switching that also considers the power consumption associated with the transition process and the return process for switching the operation mode Is realized.

  As described above, according to the power saving processing device, the power saving processing method, and the power saving processing program of the present invention, an appropriate power consumption associated with the transition process and the return process for switching the operation mode is also considered. Mode switching is realized.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(Embodiment 1)
FIG. 1 is a block diagram showing the configuration of the information processing apparatus according to Embodiment 1 of the present invention. The information processing apparatus 1000 can be used by a user as it is, but may be incorporated in various electric devices. An example of the information processing apparatus 1000 is a mobile communication terminal such as a PDA (Personal Digital Assistance) or a mobile phone. In a portable communication terminal, a small battery is used as a power source, and thus the benefits brought about by the improved power saving effect by the power saving processing device described later are enormous.

  The information processing apparatus 1000 includes a CPU (Central Processing Unit) 1, a memory device 2, a communication device 34, an input device 40, a display device 45, a timer circuit 51, and an interrupt controller 55. These devices are connected to each other through a bus line 50. Further, the hard disk device 25 and the reading device 32 can be connected to the bus line 50 as necessary. The hard disk device 25, the reading device 32, the input device 40, and the display device 45 are connected to the bus line 50 through the interfaces 26, 35, 41, and 46, respectively.

  The CPU 1 may be composed of a single CPU or a plurality of CPUs. As an example, the information processing apparatus 1000 includes a plurality of CPUs 11, 12, 13,. The memory device 2 includes a ROM (Read Only Memory) 21 and a RAM (Random Access Memory) 22. The ROM 21 stores a computer program that defines the operation of the CPU 1. The computer program can also be stored in the hard disk device 25. The CPU 1 executes processing defined by the computer program while writing the computer program stored in the ROM 21 or the hard disk device 25 to the RAM 22 as necessary. The RAM 22 also functions as a medium for temporarily storing data generated as the CPU 1 executes processing.

  The hard disk device 25 is a device that writes and reads a computer program or data to a built-in hard disk (not shown). The reading device 32 is a device that reads a computer program or data recorded on the CD-ROM 31. The communication device 34 is a device that exchanges a computer program or data between the outside and itself through an electric communication line 33 such as a telephone line. The input device 40 is a device for inputting data or the like by a user operation, and is, for example, a keyboard arranged on a PDA, an input button arranged on a mobile phone, or a detachable mouse or keyboard. The display device 45 is a device that displays data, images, and the like on a screen and displays data and the like by voice, and is, for example, an LCD (Liquid Crystal Display).

  The timer circuit 51 is a device that outputs a timer interrupt signal at a constant cycle. The interrupt controller 55 is an interrupt request signal sent from the timer circuit 51, the input device 40, a CPU other than the CPU that is executing the processing of the CPU 1, the communication device 34 as a network device, the hard disk device 25, the reading device 32, or the like. Is a device that relays to the CPU 1. Priorities are assigned to interrupt requests from each device. The interrupt controller 55 has a function of arbitrating requests according to priority when interrupts are simultaneously generated from a plurality of devices.

  As described above, the information processing apparatus 1000 is configured as a computer. The computer program can be supplied through a program recording medium such as a ROM 21, a flexible disk (not shown), a CD-ROM 31, or a transmission medium such as a telecommunication line 33. For example, a computer program recorded on a CD-ROM 31 as a program recording medium can be read out by connecting the reading device 32 to the information processing device 1000 and further stored in the RAM 22 or the hard disk device 25.

  When a computer program is supplied from the ROM 21 as a program recording medium, the CPU 1 can execute processing according to the computer program by mounting the ROM 21 in the information processing apparatus 1000. A computer program supplied through a transmission medium such as the electric communication line 33 is received through the communication device 34 and stored in the RAM 22 or the hard disk device 25, for example. The transmission medium is not limited to a wired transmission medium, and may be a wireless transmission medium. The transmission medium includes not only a communication line but also a relay device that relays the communication line, such as a router.

  The power saving processing device 10 that includes the CPU 1 and the memory device 2 that stores the power saving processing program and is configured as a computer itself is incorporated in the information processing device 1000 to change the operation mode of the information processing device 1000 normally. Switch between mode and power saving mode. The power saving processing device 10 preferably switches the operation mode between the normal mode and the power saving mode, including itself. The power saving processing device 10 is more preferably configured as an integrated circuit such as an LSI (Large Scale Integrated circuit) in which the CPU 1 and the memory device 2 are formed on a single semiconductor substrate.

  FIG. 2 is a block diagram illustrating a configuration of a program stored in the memory device 2 of the power saving processing device 10. The memory device 2 stores programs and data including one or more tasks 60 and an operating system (OS) 100 of the computer device. Each task 61, 62, 63, etc. included in the task 60 may be an application, middleware such as a file system or browser, or a part of the OS 100 such as a device driver. In FIG. 1, as an example, the task 60 is depicted as a program other than the OS 100.

  Each of the tasks 61, 62, 63, etc. included in the task 60 has a priority and is processed in the order corresponding to the priority, similarly to the tasks managed in a normal multitasking computer apparatus. When an event such as an interrupt occurs, a handler prepared in the OS 100 is executed with priority over a task. “Execution of event” means execution of a handler triggered by the occurrence of an event and subsequent execution of a system call or the like prepared in the OS 100. If the task priority changes accordingly, the task scheduler of the OS 100 causes the task 60 to be executed based on the changed priority. The OS 100 may be held in either the ROM 21 or the RAM 22.

  In order to realize the power saving processing device 10 in cooperation with the CPU 1, the OS 100 includes, as main elements, a mode switching instruction unit 75, a power consumption information management unit 101, a time prediction unit 102, a mode switching determination unit 103, and A mode switching execution unit 104 is provided. The mode switching instruction unit 75 notifies the power consumption information management unit 101 of a switching request from the normal mode to the power saving mode. When the execution of the CPU 1 is not performed for a certain period, when the battery capacity is reduced, when the user's input operation to the input device 40 is not performed for a certain period, the certain period elapses while the standby screen is displayed on the display device 45 in a stationary state. Or when the user operates the input device 40 to instruct the shift to the power saving mode, the mode switching instruction unit 75 notifies the switching request.

  The power saving mode does not need to be a single type, and a plurality of types may be prepared. In this embodiment, power saving modes are prepared in a plurality of stages with different power saving effects. When there are a plurality of power saving modes, the mode switching instruction unit 75 designates the power saving mode of the transfer destination and instructs to shift to the power saving mode. Note that the CPU 1 does not necessarily stop operating immediately before the operation mode shifts to the power saving mode, and the CPU 1 may be executing the processing of the task 60. For example, even when the standby screen is displayed in a stationary state on the display device 45, the CPU 1 is executing a task for displaying the screen.

  The power consumption information management unit 101 manages information related to operation mode switching processing (hereinafter referred to as “management information”). The power saving mode table 150 and the power consumption information table 170 illustrated in FIG. 2 correspond to specific examples of management information.

  FIG. 3 is an explanatory diagram showing an example of the power saving mode table 150 in a table format. In the power saving mode table 150, an identification number 151, an operation mode 152, and device selection information 153 are recorded in association with each other. The identification number 151 is a form of information for identifying each operation mode, that is, identification information. Instead of the identification number 151, some other identification code may be used, and generally some identification information may be used. When each power saving mode can be identified without the identification information, the identification information is useless.

  The operation mode 152 shows the processing content of each operation mode. These contents are determined by device selection information 153 that represents a combination of processes for each device element of the information processing device 1000. The power saving mode table 150 only needs to be able to manage processing for each device element as exemplified in the device selection information 153. For example, the power saving mode table 150 may consist only of the identification number 151 and the device selection information 153, and other information may be added thereto.

  The operation mode in which the identification number 151 is “0” is the normal mode, and the operation mode in which the identification number 151 is “1” “2”... Is a plurality of types of power saving modes. In the normal mode “0”, each device element is processed to exhibit its full performance. Regarding the normal mode “0”, the processing content for each device element is self-evident in the OS 100, so that it may not be recorded in the power saving mode table 150.

  The power saving mode “1” is a power saving mode in which only the external memory sleeps. In this mode, the CPU 1 has a high clock frequency, the internal memory operates normally (ON), the external memory is in standby mode (OFF), and power is supplied to the communication device 34, that is, the network interface as usual (ON). The brightness of the LCD, which is an example of the display device 45, is set high as usual.

  In addition to the elements exemplified in the device selection information 153, other various device elements to which the power saving process can be applied can be the targets of the power saving process. For example, various arithmetic processing devices can be the target of power saving processing, and the operation and stop of the CPU 1 and the operations and stopping of various processors such as a DSP can be targeted for power saving processing. Various storage devices can also be the target of power saving processing. For example, a volatile memory such as DRAM or SRAM (RAM 22 is an example), a nonvolatile memory such as a flash ROM (ROM 21 is an example), a memory card, a hard disk, a floppy (registered trademark) disk drive, or a CD drive. The reading device 32, a DVD drive, or the like can be a target of power saving processing. In addition, various input devices 40 and interfaces corresponding to the devices can be targeted for power saving processing. For example, an antenna, a key, a mouse, or a serial or parallel interface such as USB, IEEE 1394, or PCMCIA can be a target of power saving processing. Furthermore, a display device 45 such as an LCD or a CRT, or a lighting device can be a target of power saving processing.

  The contents of the power saving process are not limited to the increase / decrease of the clock frequency for each device element, ON / OFF of the standby mode, and ON / OFF of the power source. The content of the power saving process is different depending on each device element as a processing target, as exemplified by the increase / decrease in the brightness of the LCD. It is also possible to define a unique power saving process for a device element to be processed.

  In the first embodiment, a plurality of power saving modes are set. However, as described above, the power saving mode may be single. In addition, a single device element for power saving may be used. For example, only the mode that sleeps the external memory corresponding to the identification number “1” in FIG. 3 may be managed as the power saving mode. In that case, as a power saving process applied to each device element, it may be managed that the external memory is set to the standby mode (turned off) as compared with the normal mode.

  FIG. 4 is an explanatory diagram showing an example of the power consumption information table 170 in a table format. In the power consumption information table 170, two types of power consumptions 171 and 172 and power consumption 173 are recorded in association with each other in an identification number 151 and an operation mode 152 which are information shared with the power saving mode table 150 as a key. Has been. The power consumption 171 is the power consumption (mJ) generated in the information processing apparatus 1000 in accordance with the transition process from the normal mode to each power saving mode. The power consumption amount 172 is a power consumption amount (mJ) generated in the information processing apparatus 1000 due to the return processing from each power saving mode to the normal mode.

  More specifically, the power consumption 171 includes power consumption (W) and processing time (msec) required for the migration process, and the power consumption 172 includes power consumption (W) required for the return process. And processing time (msec). Instead of recording power consumption (W) and processing time (msec) as power consumption 171 and 172, power consumption (mJ) and processing time (msec) may be recorded. The power consumption amounts 171 and 172 (mJ) are overhead power consumption amounts caused by using the power saving mode. The power consumption 173 is power consumption (mW) in each operation mode.

  For example, the power saving mode with the identification number “2” is a power saving mode for sleeping the internal memory and the external memory. In this mode, the power consumption required for the transition process for switching from the normal mode to the power saving mode is 200 mW × 2 msec (= 400 mJ). This information indicates that the power consumption in the migration process is 200 mW, and that the migration process requires a processing time of 2 msec. The power consumption required for the return processing from the power saving mode to the normal operation is also 200 mW × 2 msec. The power consumed when the information processing apparatus 1000 is operating in the power saving mode “2” in which the internal memory (for example, the memory device 2) and the external memory (for example, the hard disk device 25) sleep is 70 mW.

  Each power saving mode is set when a system such as the information processing apparatus 1000 is developed. The device element to which the power saving process is applied and the content of the power saving process applied to the device element can also be set in advance. The contents recorded in the tables of FIGS. 3 and 4 can be recorded in the manufacturing process of the information processing apparatus 1000 or the like according to these setting contents. For example, actual values or theoretical values can be recorded as the power consumptions 171 and 172 and the power consumption 173.

  Returning to FIG. 2, when the mode switching request is transmitted from the mode switching instruction unit 75 to the power consumption information management unit 101, the power consumption information management unit 101 transmits the mode switching request to the time prediction unit 102. Alternatively, the mode switching request may be transmitted from the mode switching instruction unit 75 to both the power consumption information management unit 101 and the time prediction unit 102. FIG. 2 shows the former example.

  When the request for switching from the normal mode to the power saving mode is transmitted, the time prediction unit 102 predicts the time until the transfer destination power saving mode is canceled if the mode is shifted to the power saving mode. The time predicted by the time prediction unit 102 (hereinafter referred to as “prediction time”) is the time (Tu + Ts in FIG. 7 described later) from when the switching request is transmitted until the power saving mode is canceled.

  As will be described later, the mode switching determination unit 103 is based on the predicted time and the power consumption information table 170 until switching to the power saving mode until returning to normal operation (Ts in FIG. 7 described later). Is calculated. That is, the mode switching determination unit 103 calculates a period during which the information processing apparatus 1000 continues to operate in the power saving mode (hereinafter referred to as “continuation period”). The mode switching determination unit 103 determines whether to switch the operation mode from the normal mode to the power saving mode by using the duration.

  When the operation mode of the information processing apparatus 1000 is the power saving mode, the information processing apparatus 1000 cancels the power saving mode and returns to the normal operation when using the CPU 1, the memory 2, or the peripheral device as the device elements. Must. Therefore, the predicted time can be obtained by predicting the next time when the device element is used. The time prediction unit 102 includes a timer event prediction unit 74 and an iterative interrupt prediction unit 73 in order to obtain a prediction time.

  The timer event prediction unit 74 searches for a timer event registered by software (that is, a program) such as the OS 100 and various device drivers (which may be a part of the OS 100), and is nearest, that is, closest to the present. The time until the time when a future timer event occurs is obtained as the predicted time. A timer event is registered in the system in order to execute a specified process at a time specified by software. In order to realize registration and execution of a timer event, the power saving processing apparatus 10 includes a timer event registration unit 70, an event execution unit 71, and a timer list management queue 201.

  The timer event registration unit 70 registers the requested event in the timer list management queue 201 based on, for example, a registration request from the event issuing unit 61A included in the task 61. The timer list management queue 201 corresponds to a specific example of the timer event management unit of the present invention, and manages timer events. The timer list management queue 201 is held in the RAM 22 because the timer event to be managed is updated with time. In FIG. 2, the timer list management queue 201 is illustrated as not included in the OS 100, but may be a part of the OS 100.

  Each time a periodic timer interrupt is generated by the timer circuit 51, the event execution unit 71 determines whether there is a timer event to be executed by the system, that is, the information processing apparatus 1000, at that time. Confirm by referring to. The event execution unit 71 executes all timer events registered as to be executed at that time.

  When the timer event is executed, it is necessary to use the CPU 1, and thus it is often necessary to return the CPU 1 to normal operation. Furthermore, the memory 2 and peripheral devices are often used with the operation of the CPU 1. Therefore, the time when the timer event is executed can be prefetched, and the time can be regarded as the time when the system, that is, the information processing apparatus 1000 uses the device element.

  FIG. 5 is an explanatory diagram schematically illustrating a mode in which timer events are managed by the timer list management queue 201. In FIG. 5, the timer events A to C, the execution time 202, and the execution handler are information held in the timer list management queue 201 and are drawn outside the timer list management queue 201 for convenience. is there.

  As illustrated in FIG. 5, the timer event is managed in such a way that the execution time can be determined. In the example of FIG. 5, each timer event is managed by being connected in the order of timer event A, timer event B, and timer event C by a list structure. Each timer event manages a time at which the timer event is executed, an execution handler executed as processing of the timer event, data (not shown) necessary for executing the execution handler, and the like. The example of FIG. 5 indicates that the execution time 202 of the timer event A is “5”, and the timer event A is executed when the system time becomes “5”. The numerical value “5” is an example, and the execution time 202 is expressed, for example, in msec units.

  The timer event prediction unit 74 of the time prediction unit 102 searches the timer list management queue 201 to find the nearest timer event A, and acquires the execution time 202 registered in the timer event A. The timer event prediction unit 74 regards the acquired execution time 202 as the device use time, calculates the difference from the system time managed by the system, and obtains the predicted time. The timer event prediction unit 74 notifies the mode switching determination unit 103 of the predicted time.

  The iterative interrupt predicting unit 73 acquires the time until the time when the interrupt process periodically executed by the system is executed, and sets the time as the predicted time. Here, the term “periodic” is intended to include not only the case where the period is constant, but also the case where the period is repetitive with a time interval having a variation.

  A typical example of interrupt processing that is executed periodically is a timer interrupt that enters at a fixed cycle from a hardware timer. In this case, a timer circuit different from the timer circuit 51 (FIG. 1) is connected to the bus line 50. In a system employing a multi-CPU as illustrated in FIG. 1, a periodic interrupt for exchanging information to a CPU different from the CPU currently being executed may be input from the other CPU. In addition, there are periodic interrupts from peripheral devices. There is also an interrupt that enters at a constant period according to a communication protocol from a communication device or a network device (the communication device 34 in FIG. 1 is an example). For example, if the system is a mobile phone, the system must receive radio waves from the base station at regular intervals and respond to them.

  When these interrupt processes are executed, it is often necessary to return the CPU 1 to normal operation because it is necessary to use the CPU 1 as in the case of executing a timer event. Furthermore, the memory 2 and peripheral devices are often used with the operation of the CPU 1. Accordingly, the time from the present to the interrupt processing that occurs periodically can be set as the predicted time.

  In order to obtain a prediction time based on the periodic interrupt period, the power saving processing device 10 includes an interrupt recording table 220, and the iterative interrupt prediction unit 73 includes a measurement unit 72. FIG. 6 is an explanatory diagram showing an example of the interrupt recording table 220 in a table format. In the interrupt record table 220, interrupt contents 221, status 222, latest time interval 223, average time interval 224, average number of times 225, and immediately preceding interrupt time 226 are recorded in association with each other. Since the recorded information is updated with time, the interrupt recording table 220 is held in the RAM 22. In FIG. 2, the interrupt recording table 220 is illustrated as not included in the OS 100, but may be a part of the OS 100.

  The interrupt content 221 is information indicating the type of periodic interrupt. The measuring unit 72 records the time when the interrupt occurred most recently as the previous interrupt time 226 for each interrupt content. Each time a new interrupt occurs, the previous interrupt time 226 is updated. The measurement unit 72 calculates the latest time interval 223 and the average time interval 224 each time a new interrupt occurs. The latest time interval 223 is information indicating the difference between the immediately preceding periodic interrupt time and the previous periodic interrupt time, that is, the latest interrupt time interval. Each time a new interrupt occurs, the measuring unit 72 calculates the difference between the time when the new interrupt occurs and the previous interrupt time 226 before the update, and records it as the latest time interval 223.

  Further, every time a new interrupt occurs, the measuring unit 72 calculates an average value of the time intervals of the latest interrupts for a predetermined number of times, and records the average value as the average time interval 224. The measuring unit 72 records the average time interval 224 and, at the same time, records the average number of times when calculating the average time interval 224 as the average number of times 225. In the example of FIG. 6, “10 times” is recorded as the average number of times 225.

  Each time a new interrupt occurs, the measurement unit 72 calculates a new average time interval 224 based on the average time interval 224, the average number of times 225, and the time when the new interrupt occurs. Even if the average number of times 225 is set to “10 times” during steady operation, it is less than “10 times” immediately after the start of creation of the interrupt record table 220, such as immediately after the system is started up. The measurement unit 72 can calculate the average time interval 224 from the first time by sequentially incrementing the average count 225 from the initial value “1”. When the average count 225 is “1”, the average time interval 224 is the same as the latest time interval 223.

  Note that the average time interval 224 does not have to be an average value of interrupt time intervals for the past certain number of times, and may be an average value of time intervals of all past interrupts. In this case, the average count 225 is incremented by “1” indefinitely every time an interrupt occurs.

  The measuring unit 72 that manages the interrupt recording table 220 detects that a specific periodic interrupt illustrated in FIG. 6 has occurred. For example, the measurement unit 72 detects that a specific interrupt has occurred by detecting that an interrupt signal has been transmitted from the interrupt controller 55 to an arithmetic processing device such as the CPU 1. Alternatively, when software such as the OS 100 discriminates an interrupt from the target device, that is, an apparatus element of the information processing apparatus 1000, and performs an associated interrupt process, the system time or the hardware timer clock value is acquired. May be notified to the measurement unit 72 which is a part of the OS 100.

  The repetitive interrupt predicting unit 73 included in the time predicting unit 102 may occur in the nearest future by referring to the latest time interval 223 and the immediately preceding interrupt time 226 for each interrupt content 221 in FIG. The time of an interrupt is detected, and the difference between this and the current time is taken as the predicted time. The iterative interrupt prediction unit 73 may use the average time interval 224 instead of the latest time interval 223.

  Depending on the system operating status, interrupts may be disabled. The state 222 is information for displaying whether or not the interrupt is set to be invalid for each interrupt content 221. For example, if the interrupt controller 55 is set to mask an interrupt, the masked interrupt is not accepted. For the masked interrupt, “invalid” is recorded as the state 222. In this case, a portion (not shown) in the OS 100 can detect the setting state of the interrupt controller 55 and record the state in the state 222.

  In addition, it is possible to set validity / invalidity for each interrupt content 221 by software such as the OS 100 without using a mask setting in the interrupt controller 55. In this case, a part such as the OS 100 that performs the setting can record the set content in the state 222.

  The iterative interrupt prediction unit 73 also refers to the state 222 when acquiring the prediction time. The iterative interrupt prediction unit 73 refers to data such as the latest time interval 223 only for the interrupt contents 221 in which the state 222 is not set to “invalid”. As a result, the iterative interrupt prediction unit 73 can acquire the prediction time more accurately.

  Note that the iterative interrupt predicting unit 73 determines from the interrupt recording table 220 the time to return to the normal mode from the power saving mode instead of the time until the power saving mode is canceled (Tu + Ts + Td in FIG. 7 described later). ) Can be acquired as the predicted time. Instead of the previous interrupt time 226 recorded in the interrupt recording table 220, the time at which a predetermined device (apparatus element of the information processing apparatus 1000) starts operating after interruption is restored. It is possible to record. In this case, the iterative interrupt predicting unit 73 can acquire the time until returning from the power saving mode to the normal mode based on the previous interrupt time 226 as the predicted time.

  Returning to FIG. 2, the time prediction unit 102 uses, for example, the prediction time obtained by the timer event prediction unit 74 as a first candidate and the prediction time obtained by the iterative interrupt prediction unit 73 as a second candidate. A candidate close to the present is notified to the mode switching determination unit 103 as a predicted time.

  The mode switching determination unit 103 determines whether to switch the current normal mode to the power saving mode based on the management information managed by the power consumption information management unit 101 and the predicted time predicted by the time prediction unit 102. The power consumption information management unit 101 notifies the mode switching determination unit 103 of the power consumption information table 170 managed by itself.

  FIG. 7 is a graph for explaining the operation of the mode switching determination unit 103, and illustrates the transition of the power consumption accompanying the switching of the operation mode. In FIG. 7, the vertical axis indicates power consumption (mW), and the horizontal axis indicates time. The power consumption when the operation mode of the system is the normal mode is at the height of Wn. When a request for switching to the power saving mode is generated at time 251, power consumption increases because a process for switching to the power saving mode, that is, a transition process is performed. This is because, firstly, in the normal mode immediately before switching from the normal mode to the power saving mode, the system usually does not have a large process. Secondly, as processing for switching to the power saving mode, it is necessary to perform processing for changing settings of various devices (that is, apparatus elements), and high power is consumed for this processing. In the example of FIG. 7, in order to switch to the power saving mode, a processing time is required for the time Tu from time 251 to time 252, and the power consumption Wu during that time is raised from Wn before switching to the power saving mode.

  When the transition process, which is the pre-process for switching to the power saving mode, is completed at time 252 and the mode is switched to the power saving mode, the power consumption decreases to the level of Ws. The power consumption Ws is lower than the power consumption Wn in the normal mode. The operation in the power saving mode continues for the duration Ts until the time 253 when the interruption of the power saving mode is generated while maintaining the power consumption at the level of Wd. When an interrupt for canceling the power saving mode occurs at time 253, the system performs processing to return from the power saving mode, that is, recovery processing. In the return process, it is necessary to change the settings of various devices as in the migration process. Since the power required for the processing is consumed, the power consumption Wd required for the return processing increases to a level that is equal to or close to the power consumption Wu.

  Processing time over time Td from time 253 to time 254 is required for the process of returning from the power saving mode to the normal mode. When the return process as the pre-process for the normal mode is completed at time 254, the operation mode returns to the normal mode.

  As described above, switching to the power saving mode requires the processing time Tu for switching to the power saving mode and the processing time Td for returning from the power saving mode. For this reason, it is not always advantageous to switch to the power saving mode. In some cases, it is better to maintain the normal operation mode without switching to the power saving mode.

  When the switching request to the power saving mode is notified, the mode switching determination unit 103 determines whether to switch to the power saving mode based on the above-described situation. The mode switching determination unit 103 may directly receive a switching request from the mode switching instruction unit 75, but may indirectly receive a notification through the power consumption information management unit 101 or the time prediction unit 102. FIG. 2 illustrates the latter.

  Hereinafter, some examples will be described with respect to the switching determination criterion and determination procedure of the mode switching determination unit 103. First, an example in which the mode switching determination unit 103 makes a determination based on the processing time is shown.

  When the processing time Tu for switching to the power saving mode is longer than the time Tu + Ts from the occurrence of the switching request to the cancellation of the power saving mode, the time until the power saving mode is canceled after switching to the power saving mode. It means that there is no time, ie duration Ts. In this case, the operation mode returns to the normal mode until the operation in the power saving mode cannot be realized. Therefore, the time required for the transition process for switching to the implemented power saving mode and the restoration process for returning from the power saving mode is wasted. Further, if the operation in the normal mode is maintained, a process that can be immediately responded and executed may be delayed because a delay occurs in the response due to the transition process or the return process.

  Therefore, the mode switching determination unit 103 is based on the relationship between the prediction time (Tu + Ts or Tu + Ts + Td) received from the time prediction unit 102 and the processing time Tu for transition processing or the processing time Td for return processing. It is determined whether or not to switch to the power saving mode. For example, when the predicted time is obtained as Tu + Ts, the mode switching determination unit 103 determines not to switch to the power saving mode if the predicted time is shorter than the processing time Tu. Further, when the predicted time is obtained as Tu + Ts + Td, the mode switching determining unit 103 determines not to switch to the power saving mode if the predicted time is shorter than the sum of the processing time Tu and the processing time Td. In another example, only when the mode switching determination unit 103 determines that the prediction time is sufficiently long to be equal to or greater than the value obtained by adding a certain positive constant to the processing time Tu or the sum of processing times Tu + Td. It is determined that the mode should be switched.

  The above example can be paraphrased as follows. The mode switching determination unit 103 first calculates a time during which the system can operate in the power saving mode, that is, a duration Ts. The duration Ts is obtained by subtracting the processing time Tu from the prediction time when the prediction time is obtained as Tu + Ts, and is subtracted from the prediction time by the processing time Tu + Td when the prediction time is obtained as Tu + Ts + Td. can get.

  The mode switching determination unit 103 can acquire the processing times Tu and Td by referring to the power consumption information table 170 notified by the power consumption information management unit 101. Instead of the power consumption information management unit 101 transmitting the power consumption information table 170 to the mode switching determination unit 103, the mode switching determination unit 103 may refer to the power consumption information table 170 managed by the power consumption information management unit 101. Good.

  For example, the mode switching determination unit 103 determines that switching to the power saving mode is not performed when the duration Ts is a negative value, and determines that switching is performed when the duration Ts is a positive value. . In another example, the mode switching determination unit 103 determines that switching is performed when the duration Ts is greater than or equal to a given positive constant, and switches when the duration Ts is less than the positive constant. Is determined not to be performed. In other words, the mode switching determination unit 103 determines that switching is performed only when the duration Ts is sufficiently long.

  Next, an example is shown in which the mode switching determination unit 103 makes a determination based on the power consumption. First, the mode switching determination unit 103 calculates the duration Ts from the predicted time received from the time prediction unit 102. The mode switching determination unit 103 further includes a power consumption (Wu × Tu) required for the transition process for shifting to the power saving mode and a power consumption (Wd × Td) required for the return process for returning to the normal operation from the power saving mode. Is obtained from the power consumption information table 170. Alternatively, the mode switching determination unit 103 may calculate the power consumption (Wu × Tu) required for the transition process by acquiring the power consumption Wu required for the transition process and the processing time Tu required for the transition process. . Similarly, the mode switching determination unit 103 calculates the power consumption (Wd × Td) required for the return process by acquiring the power consumption Wd required for the return process and the processing time Td required for the return process. good.

  The mode switching determination unit 103 further acquires the power consumption Ws during the duration Ts that operates in the power saving mode from the power consumption information table 170. The mode switching determination unit 103 calculates the power consumption (Ws × Tu) in the duration Ts from the duration Ts and the power consumption Ws. As a result, when switching to the power saving mode, the mode switching determination unit 103 determines the total power consumption (Wu × Tu + Ws × Ts + Wd × Td) over the entire period of Tu + Ts + Td as the sum of the three types of power consumption. Calculate as

  Further, the mode switching determination unit 103 acquires the power consumption Wn when operating in the normal mode from the power consumption information table 170. Regarding the power consumption Wn, there are various acquisition forms within the range of a well-known technique, such as being given to the mode switching determination unit 103 in advance as a constant. Based on the power consumption Wn, the mode switching determination unit 103 calculates the total power consumption (Wn × (Tu + Ts + Td)) over the entire period Tu + Ts + Td when the operation mode is not switched.

  Based on the above results, the mode switching determination unit 103 compares the total power consumption between the case where the mode is switched to the power saving mode and the case where the mode is not switched. It is determined whether or not to perform switching. For example, if the total power consumption when switching to the power saving mode is greater than the total power consumption when not switching, the power saving effect cannot be obtained by switching to the power saving mode. The unit 103 determines not to switch to the power saving mode. Conversely, if the total power consumption when switching to the power saving mode is smaller than the total power consumption when not switching, a power saving effect can be obtained by switching to the power saving mode. Unit 103 determines to switch to the power saving mode.

  In another example, as a result of the comparison, the mode switching determination unit 103 determines that the total power consumption when switching to the power saving mode is a given margin (positive number) from the total power consumption when not switching. It is determined that switching to the power saving mode is performed only when the value is equal to or less than the value obtained by subtracting. As a result, the switching to the power saving mode can be performed only when the power saving effect that more than compensates for the disadvantage of response delay accompanying the switching can be obtained.

  The mode switching determination unit 103 informs the mode switching execution unit 104 of the determination result. The mode switching determination unit 103 may notify the mode switching execution unit 104 only when it is determined to switch to the power saving mode.

  The mode switching execution unit 104 switches the operation mode according to the determination of the mode switching determination unit 103, thereby realizing each operation mode. That is, when the mode switching execution unit 104 is notified of the switching to the power saving mode from the mode switching determination unit 103, the mode switching execution unit 104 performs a process of switching the system operation mode to the power saving mode. For example, the mode switching execution unit 104 refers to the power saving mode table 150 to perform an operation corresponding to the power saving mode to be transferred to each device element. The mode switching execution unit 104 performs various processes associated with operations recorded in the power saving mode table 150 in order to apply the power saving process to each device element targeted by the power saving mode. Perform in a predetermined procedure.

  In general, when performing power-saving measures such as turning off the power of each device element, setting it to standby mode, or stopping it, in order to return to normal operation from power-saving mode and then operate normally, Processing to store temporary information and volatile data held during normal operation is required. In addition, the connected peripheral device may be notified that the power is turned off, in the standby mode, or stopped, so that data cannot be transmitted or received.

  For example, when the power of a volatile external memory (not shown in FIG. 1) is turned off, first of all data stored in the external memory is written in the external memory. It must be reflected in the position of the storage device or moved to another temporary storage device. In some cases, it may be necessary to mask a refresh signal or an activation signal that has been periodically received from another connected peripheral device when power is applied.

  Further, when changing the state of each device element, it is necessary to wait until the state of each device element is stabilized after performing a predetermined setting for each device element. For example, when the voltage to be supplied is reduced as the CPU clock frequency is reduced, the CPU 1 must be stopped during the time when the voltage supply source changes the voltage or the time until the voltage stabilizes. .

  The mode switching execution unit 104 executes predetermined processing for implementing the power saving mode, including the above processing.

  The operation of the power saving processing apparatus 10 configured as described above will be described with reference to the flowchart of FIG. In the power saving processing apparatus 10, when processing is started, for example, when a power supply is turned on, the power consumption information management unit 101 manages management information such as the power consumption information table 170. At the same time, the time prediction unit 102 manages the interrupt recording table 220 (S101).

  Next, when a request for switching to the power saving mode for suppressing power consumption, that is, a switching command is generated, the power saving processing device 10 executes the processing from step S102 onward. The process of step S101 is continuously executed in parallel with the process of step S102 and subsequent steps.

  In step S102, the time prediction unit 102 calculates a prediction time. Next, the mode switching determination unit 103 acquires management information such as the power consumption information table 170 from the power consumption information management unit 101, and acquires a predicted time from the time prediction unit 102 (S103). Next, the mode switching determination unit 103 compares the processing time or the total power consumption between when switching to the power saving mode and when not switching (S104). Subsequently, the mode switching determination unit 103 determines whether switching to the power saving mode is effective based on the comparison result (S105). Subsequently, when it is determined that the switching is valid (Yes in S105), the mode switching execution unit 104 switches to the power saving mode (S106).

  As described above, according to the power saving processing apparatus 10 according to the first embodiment of the present invention, the processing time and power consumption that are overhead when switching to the power saving mode are also taken into consideration, and the power saving mode is set. By determining whether or not to switch, it is possible to achieve more advantageous power saving control or more accurate power saving control.

(Embodiment 2)
In the first embodiment described above, as one method in which the time prediction unit 102 predicts the use time of a device, that is, an apparatus element, the timer event is searched and the power saving mode is set up to the time when the nearest timer event occurs. It was possible time for operation. However, when a certain timer event occurs, the device to which the timer event applies power saving processing is not necessarily used by returning to normal operation.

  For example, there is a possibility that a network interface, that is, the communication device 34 is not used only by loading a code from an external memory and performing a predetermined process in the arithmetic processing unit, that is, the CPU 1 by a certain timer event. In such a case, for example, the power saving mode of “powering off the network interface” corresponding to the identification number “4” shown in FIG. 3 does not need to be canceled by the timer event.

  Therefore, some timer events use only a predetermined device or do not use a predetermined device, and if they can be identified, it is possible to perform a power saving mode operation for a requested power saving mode. Time can be predicted accurately.

  An operation in which the time prediction unit 102 predicts the use time of a device using a timer event while performing such identification will be described with reference to FIG. FIG. 9 corresponds to FIG. 5 in the first embodiment, and is an explanatory diagram schematically illustrating a mode in which timer events are managed by the timer list management queue according to the second embodiment. The timer list management queue 201A is replaced with the timer list management queue 201 in FIG.

  The timer list management queue 201A manages device usage information corresponding to each timer event. That is, each timer event is accompanied by device usage information in addition to the execution time and execution handler shown in FIG. For example, in the timer event A, information that the external memory is not used and information 301 that the network interface is not used are managed as device information. In the timer event B, information 302 that the network interface is not used is managed as device information.

  When registering a timer event in the timer list management queue 201A, the timer event registration unit 70 (FIG. 2) can preset device usage information 301 and 302 based on the specification of the timer event. . In addition, the time prediction unit 102 stores which device the timer event has accessed at the time of execution of the timer event, and based on the information, the time prediction unit 102 or the timer event registration unit 70 stores the device usage information in the timer It may be set in the list management queue 201A.

  If, in the power saving mode table 150 shown in FIG. 3, the power saving mode for “sleeping the external memory” corresponding to the identification number “1” is requested as the switching destination, the time prediction unit 102 The timer event managed by the timer list management queue 201A of No. 9 is searched, and the device usage information 301 of the timer event A is referred to obtain information that the timer event A does not use the external memory. That is, the timer event A is determined to be a timer event that does not need to return from the power saving mode “external memory sleep”.

  The time prediction unit 102 further searches for a managed timer event, refers to the device usage information 302 of the timer event B, and obtains information that the timer event B does not use the network. As in the example of FIG. 9, when a device that is not used is registered in the device usage information, the time prediction unit 102 determines that the timer event B may use an external memory, and the timer event B Reference is made to the execution time 303 registered in. The time prediction unit 102 regards the execution time 303 as the device use time, and calculates the difference from the system time managed by the system to obtain the time (Tu + Ts) until the power saving mode operation is canceled. The time prediction unit 102 notifies the mode switching determination unit 103 of the calculated time as the predicted time.

  Furthermore, as another example, the case where the power saving mode for turning off the network interface corresponding to the identification number “4” is requested as the switching destination in the power saving mode table 150 shown in FIG. . In this case, since the device usage information 301 and 302 of the timer event A and the timer event B includes information that the network interface is not used, the time prediction unit 102 uses the device usage information of the timer event C as the device usage information. refer. When the device usage information does not exist as in the timer event C, the time prediction unit 102 determines that there is a possibility of using all devices, and based on the execution time 304 of the timer event C, the power saving mode Predict the possible time of action.

  In FIG. 9, information indicating that a specific device is not used is exemplified as device usage information corresponding to a timer event. However, the timer list management queue 201A may manage information indicating that a specific device is used. . In this case, the time prediction unit 102 includes a part of the device usage information in which the device used by the timer event is recorded, including a part of the device to which the power saving process is applied in accordance with the execution of the requested power saving mode. Determine whether or not. Then, the time prediction unit 102 regards the execution time of the timer event accompanied by such device usage information as the time to use the device, and calculates the time during which the power saving mode operation can be performed.

  Next, the operation when the time prediction unit 102 predicts the device use time based on the periodic interrupt process while identifying the device to be used will be described with reference to FIG. FIG. 10 corresponds to FIG. 6 in the first embodiment, and is an explanatory diagram showing the interrupt recording table 220A according to the second embodiment in a table format. This interrupt record table 220A is replaced with the interrupt record table 220 in FIG.

  In the interrupt record table 220A, as in the interrupt record table 220 of FIG. 6, the interrupt contents 221, the state 222, the latest time interval 223, the average time interval 224, the average number of times 225, and the immediately preceding interrupt time 226 are mutually stored. It is recorded in association. Device usage information 355 is recorded in the interrupt recording table 220A in association with the interrupt content 221 and the like.

  By using the device usage information 355, the time prediction unit 102 can predict the device usage time more accurately. Depending on the power saving mode, the power saving mode may not be canceled because a specific interrupt has actually occurred. This is because not all periodic interrupt processing uses a device that has been subjected to power saving processing in the power saving mode. Therefore, the time prediction unit 102 does not regard the time of occurrence of a periodic interrupt that is predicted to be closest to the present time as the next time to use the device, but device usage information managed for each interrupt content 221. 355 is used. Thereby, the time prediction unit 102 can more accurately obtain the predicted time for the requested power saving mode.

  Specifically, as in the case of the timer event described above, the time predicting unit 102 determines that a periodic interrupt is applied to each device for which the power saving mode for which switching is requested is an application target of the power saving process. Whether or not to use the device is determined based on the device usage information 355. The device usage information 355 can be set in advance in an execution handler that executes a periodic interrupt, and the time prediction unit 102 can read it. Further, when the periodic interrupt is executed, the time prediction unit 102 stores which device the periodic interrupt has accessed, and the time prediction unit 102 sets the device usage information 355 based on the information. Good.

  For example, if a power saving mode of “sleep external memory” corresponding to the identification number “1” in FIG. 3 is requested, the time prediction unit 102 searches the interrupt recording table 220A in FIG. With reference to the device usage information 355 of the first “timer interrupt”, information that the external memory is not used is obtained. Thereby, the time prediction unit 102 can determine that the power saving mode “sleep external memory” is canceled by the timer interrupt and does not return to the normal mode.

  Next, the time prediction unit 102 refers to the device usage information 355 of the second periodic interrupt “periodic interrupt from another CPU” in FIG. As a result, since there is no information that the external memory is not used, the time prediction unit 102 can determine that the second periodic interrupt uses the external memory. That is, the time prediction unit 102 determines that the latest time interval 223 and the average time interval 224 corresponding to the second periodic interrupt in FIG. 10 are effective times for the power saving mode “sleep external memory”. .

  Thus, by referring to the effective time interval in consideration of the device usage information 355 among the periodic interrupt information managed in the interrupt recording table 220A illustrated in FIG. The operation time in the mode can be predicted. Further, as in the case of the timer event described above, it is also possible to record not only information that a specific device is not used but information that a specific device is used in the device usage information 355.

(Embodiment 3)
In the power consumption information table 170 illustrated in FIG. 4, overhead power consumption amounts 171 and 172 associated with switching from the normal mode to each power saving mode are recorded. However, when the current operation mode is one of the power saving modes, the information processing apparatus 1000 can be configured so that the operation mode can be switched to another power saving mode. When the operation mode is switched from one power saving mode to another power saving mode, the difference in the state of each device is smaller than when switching from the normal mode to the power saving mode, which is accompanied by the switching of the operation mode. Overhead power consumption may be reduced.

  Even in such a case, in order to obtain the power consumption associated with the operation mode switching with high accuracy, the power consumption associated with the operation mode switching is reduced even when switching from one power saving mode to another. It can be used to determine whether or not to switch the operation mode.

  FIG. 11 is an explanatory diagram illustrating, in tabular form, a power consumption information table that can be used for switching between any of the normal mode and a plurality of power saving modes. The power consumption information table 170A is replaced with the power consumption information table 170 in FIG. In the power consumption information table 170A illustrated in FIG. 11, two types of power consumption and power consumption are arranged in a matrix. In FIG. 11, the current operation mode is arranged in the horizontal direction, and the operation mode of the transfer destination is arranged in the vertical direction. For example, when determining whether or not to switch from the operation mode “1”, which is the power saving mode, to another power saving mode “3”, the mode switching determination unit 103 has four rows and two columns (vertical fourth row). Reference is made to the power consumptions 171A and 172A and the power consumption 173A recorded in the second row). In order to calculate the total power consumption when switching from the operation mode “1” is not performed, the mode switching determination unit 103 may refer to the power consumption 173 recorded in 2 rows and 1 column.

  When switching from one power saving mode to the normal mode, it is not normally assumed that the mode switching determination unit 103 should perform switching appropriateness. However, the mode switching determination unit 103 can use the power consumption information table 170A to allow the mode switching determination unit 103 to determine whether switching is appropriate when switching from one power saving mode to the normal mode.

  FIG. 12 is a flowchart showing an operation procedure of the power saving processing device 10 according to the third embodiment. This process is executed after the operation mode is switched to one power saving mode by the process of FIG. However, in step S101 of FIG. 8, the power consumption information management unit 101 manages the power consumption information table 170A as one piece of management information instead of the power consumption information table 170. When a request to switch the current power saving mode to another power saving mode is generated, first, in the power saving processing device 10, the time prediction unit 102 acquires the predicted time (S202).

  Next, the mode switching determination unit 103 acquires management information such as the power consumption information table 170A from the power consumption information management unit 101, and acquires a predicted time from the time prediction unit 102 (S203). Next, the mode switching determination unit 103 compares the processing time or the total power consumption between when switching to another power saving mode and when not switching (S204). Subsequently, the mode switching determination unit 103 determines whether switching to the power saving mode is effective based on the comparison result (S205). Subsequently, when it is determined that the switching is valid (Yes in S205), the mode switching execution unit 104 switches to the power saving mode (S206).

  According to the above procedure, appropriate switching in consideration of the power consumption required for the transition process and the return process is realized even when the operation mode is switched between different power saving modes.

(Embodiment 4)
The power saving processing device according to the fourth embodiment of the present invention not only determines whether or not switching to a specific power saving mode is appropriate, but also among the plurality of power saving modes prepared by the system, that is, the information processing device 1000 The function of selecting and executing the optimum power saving mode is provided, thereby realizing more accurate power saving.

  The power saving processing apparatus according to the fourth embodiment will be described below. The configuration of the power saving processing device according to the fourth embodiment of the present invention is depicted in the same way as the power saving processing device 10 of FIG. However, as illustrated in FIG. 3 and FIG. 4, the mode switching instruction unit 75 normally does not designate a mode to be a transition destination even though a plurality of modes are prepared as the power saving mode. Request switching from mode to power saving mode. Moreover, the time prediction unit 102 calculates the predicted time when the transition is made for all of the prepared power saving modes except the current mode.

  The mode switching determination unit 103 calculates the total power consumption when mode switching is performed for all of the prepared power saving modes except the current mode, and selects the mode with the lowest total power consumption. Choose the best migration destination. Instead of comparing the total power consumption, the mode switching determination unit 103 may select the mode with the longest duration Ts after the mode transition as the optimum power saving mode. The mode switching determination unit 103 further determines whether or not it is appropriate to switch from the normal mode to the power saving mode for the selected power saving mode in the same manner as the mode switching determination unit 103 of the first embodiment. May be. The mode switching execution unit 104 executes mode switching according to the determination result of the mode switching determination unit 103 as in the case of the first embodiment.

  FIGS. 13 and 14 are graphs for explaining the operation of the mode switching determination unit 103, and illustrate the transition of power consumption (mW) accompanying the switching of the operation mode. FIG. 13 and FIG. 14 show the transitions of power consumption when switching to two power saving modes, power saving mode A and power saving mode B, so that they can be compared with each other.

  In general, in order to obtain a high power saving effect while keeping power consumption low, a larger overhead is required. Predict the duration that can operate in power saving mode, and calculate power consumption and processing time overhead required for transition processing to switch to power saving mode and return processing to return to normal mode, and compare with each other Thus, it is possible to select an optimum power saving mode that solves the trade-off.

  In the power saving mode A, compared with the power saving mode B, the power consumption (mW) during operation in the power saving mode is small, and the power saving effect per unit time is high. Referring to FIGS. 13 and 14, the power consumption when the system operates in the power saving mode A over the duration from time 452 to time 453 is WsA, and the power saving mode over the duration from time 462 to time 463. The power consumption when operating at B is kept lower than WsB.

  However, the overhead when switching to the power saving mode A is larger than when switching to the power saving mode B. Referring to FIGS. 13 and 14, the processing time TuA from time 451 to time 452 required for the transition processing to switch to the power saving mode A is greater than the processing time TuB from time 461 to time 462 required for the transition processing to switch to the power saving mode B. Also long. As a result, the power consumption (mJ) required for the transition process is larger when switching to the power saving mode A. Similarly, the processing time TdA from time 453 to time 454 required for the return processing for returning from the power saving mode A to the normal mode is the time 463 to time 464 required for the return processing for returning from the power saving mode B to the normal mode. Is longer than the processing time TdB. As a result, the power consumption required for the return processing is greater when returning from the power saving mode A to the normal mode.

  For example, for the power saving mode A shown in FIG. 13, the mode switching determination unit 103 calculates the total power consumption from when it is requested to switch to the power saving mode at time 451 until it returns to normal operation at time 454. Calculate based on the power consumption and time of the section. The power consumption required for the transition process for switching to the power saving mode A can be calculated as the product of WuA and TuA (WuA × TuA). Further, the power consumption during the continuous period of operation in the power saving mode A can be calculated as a product of WsA and TsA (WsA × TsA). Furthermore, the power consumption required for the return process for returning from the power saving mode A to the normal mode can be calculated as the product of WdA and TdA (WdA × TdA). The power consumption consumed from the request for switching to the power saving mode A until the return is obtained by the sum of the power consumption in each section described above.

  For example, also in the power saving mode B shown in FIG. 14, the mode switching determination unit 103 calculates the total power consumption based on the power consumption and time of each section. The total power consumption for the power saving mode B is WuB × TuB consumed in the transition processing to the power saving mode B, WsB × TsB consumed in the continuous period of operation in the power saving mode B, and the power saving mode B From the sum of WdB × TdB consumed in the return processing from normal mode to normal mode.

  The mode switching determination unit 103 includes a power consumption information table 170 transmitted from the power consumption information management unit 101 for each power saving mode that the system can take as a transition destination, and a predicted time for each power saving mode transmitted from the time prediction unit 102. Based on the above, the sum of the total power consumption is calculated in the procedure exemplified for the power saving modes A and B. The mode switching determination unit 103 further selects a power saving mode in which the calculated total power consumption is the smallest.

  The operation of the power saving processing apparatus 10 according to the fourth embodiment configured as described above will be described with reference to the flowchart of FIG. In the power saving processing device 10 according to the fourth embodiment, when the processing is started, for example, when the power is turned on, the power consumption information management unit 101 manages management information such as the power consumption information table 170. At the same time, the time prediction unit 102 manages the interrupt record table 220 (S401).

  Next, when a request (command) for switching to the power saving mode for suppressing power consumption is generated, the power saving processing apparatus 10 executes the processing from step S402 onward. The process in step S401 is continuously executed in parallel with the processes in step S402 and subsequent steps.

  In step S402, the time prediction unit 102 calculates prediction times for all power saving modes other than the current mode. Next, the mode switching determination unit 103 acquires management information such as the power consumption information table 170 from the power consumption information management unit 101, and acquires a predicted time for each power saving mode from the time prediction unit 102 (S403). Next, the mode switching determination unit 103 selects an optimum power saving mode by comparing the duration or the total power consumption among the power saving modes that can be selected (S404). Subsequently, the mode switching determination unit 103 determines whether or not switching to the selected power saving mode is effective (S405). Subsequently, when it is determined that the switching is valid (Yes in S405), the mode switching execution unit 104 switches to the power saving mode (S406).

  The mode switching determination unit 103 selects an optimum power saving mode from the power saving modes in step S404, and then selects it as it is without determining whether switching to the power saving mode is effective in step S405. The mode switching execution unit 104 may be notified to execute the power saving mode. That is, the mode switching determination unit 103 may cause the mode switching execution unit 104 to execute an optimum power saving mode from among selectable power saving modes in consideration of the overhead for switching to the power saving mode.

(Other embodiments)
(1) In each of the above embodiments, the time predicting unit 102 has both the timer event predicting unit 74 and the iterative interrupt predicting unit 73, but it is also possible to adopt a form having only one of them. It is.

  (2) In the fourth embodiment, the mode switching determination unit 103 assumes all the power saving modes other than the current operation mode as candidates for the transfer destination from the current operation mode, and makes an optimal transition from them. I chose a destination. On the other hand, it is also possible to limit to a power saving mode within a certain range as a migration destination candidate. In this case, it is possible for the mode switching instruction unit 75 to instruct a predetermined range. The predetermined range may be different depending on which of the current operation modes. Further, as in the fourth embodiment, setting all the power saving modes other than the current operation mode as candidates for the transfer destination is equivalent to setting the predetermined range to such a range. Furthermore, when the normal mode is also included in the transfer destination candidates, this corresponds to no limitation on the transfer destination. In this case, it is equivalent to setting the predetermined range to all operation modes other than the current mode.

  (3) Each table illustrated in FIGS. 3 and 4 records each information for each operation mode. In contrast, each piece of information may be recorded for each device element to which the power saving process is applied. For example, in the tables of FIG. 3 and FIG. 4, the identification number “2” records information on the power saving mode for sleeping the internal memory and the external memory. Information may be recorded separately in the case of making it sleep alone.

  For switching to the power saving mode that causes the internal memory and the external memory to sleep at the same time, the mode switching determination unit 103 uses the power required for the processing to be performed on these two device elements as the transition processing to the power saving mode. By adding the consumption amount, the power consumption amount required for the migration process can be acquired. In addition, as the power consumption 173 in FIG. 4, the power consumption when the power saving process is applied to each device element may be recorded instead of the power consumption when the system is operating in each operation mode. As a result, the mode switching determination unit 103 adds the power consumption when the internal memory is put to sleep and the power consumption when the external memory is put to sleep so that the operation mode sleeps both the internal memory and the external memory. The power consumption when in the power mode can be acquired. As described above, the case where the internal memory and the external memory are set to sleep has been described as an example.

  A power saving processing device, a power saving processing method, and a power saving processing program according to the present invention perform power saving processing in consideration of overhead when switching to a power saving mode in a system that implements a power saving mode, that is, a target device. Therefore, since it has a function of suppressing power consumption, it is useful in devices that consume power, such as information devices, AV devices, communication devices, and home appliances.

It is a block diagram which shows the structure of the information processing apparatus by Embodiment 1 of this invention. FIG. 2 is a block diagram illustrating a configuration of a program stored in the memory device of FIG. 1. It is explanatory drawing which shows an example of the power saving mode table of FIG. 1 in a table format. It is explanatory drawing which shows an example of the power consumption information table of FIG. 1 in a table format. It is explanatory drawing which drew typically the form which the timer list management queue of FIG. 1 manages a timer event. It is explanatory drawing which shows an example of the interruption recording table of FIG. 1 in a table format. It is a graph explaining operation | movement of the mode switching determination part of FIG. It is a flowchart which shows the operation | movement procedure of the power saving processing apparatus of FIG. It is explanatory drawing which drew typically the form which the timer list management queue by Embodiment 2 of this invention manages a timer event. It is explanatory drawing which shows the interruption recording table by Embodiment 2 of this invention in a table format. It is explanatory drawing which illustrates the power consumption information table by Embodiment 3 of this invention in a table format. It is a flowchart which shows the operation | movement procedure of the power saving processing apparatus by Embodiment 3 of this invention. It is a graph explaining operation | movement of the mode switching determination part by Embodiment 4 of this invention. It is a graph explaining operation | movement of the mode switching determination part by Embodiment 4 of this invention. It is a flowchart which shows the operation | movement procedure of the power saving processing apparatus by Embodiment 4 of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Power saving processing apparatus 74 Timer event prediction part 73 Repetitive interrupt prediction part 75 Mode switching instruction part 101 Power consumption information management part 102 Time prediction part 103 Mode switching determination part 104 Mode switching execution part 150 Power saving mode table (management information)
170 Power consumption information table (management information)
201 timer list management queue (timer event management section)
301, 302, 355 Device usage information (device usage information)
153 Device selection information

Claims (19)

A power saving processing device that switches an operation mode of a target device between a normal mode and a plurality of modes including one or more power saving modes,
A power consumption information management unit for managing information related to the operation mode switching process;
When a request for switching from the current mode to another mode is generated among the plurality of modes, the time until the other mode is canceled or the current mode is restored when the switching request is satisfied. A time prediction unit for predicting the time until
Based on the management information that is the information managed by the power consumption information management unit and the predicted time that is the time predicted by the time prediction unit, a period during which the other mode continues is calculated, and the calculated value is A mode switching determination unit that determines whether to switch the operation mode from the current mode to the other mode;
A mode switching execution unit that switches the operation mode of the target device according to the determination of the mode switching determination unit;
The management information is a processing time required for a transition process from the current mode to the other mode and a processing time required for a return process from the different mode to the current mode. A power-saving processing device that includes information that can derive a period during which each of the other modes continues according to the predicted time for.   The power saving processing apparatus according to claim 1, wherein the one or more power saving modes are two or more power saving modes. A power saving processing device that switches an operation mode of a target device between a plurality of modes including a normal mode and two or more power saving modes,
A power consumption information management unit for managing information related to the operation mode switching process;
When a request for switching from the current mode of the plurality of modes to a mode within a specific range including two or more other modes is generated, each mode within the specific range is canceled when the switching request is met A time prediction unit that predicts the time until the current mode or the time until the current mode is restored for each mode within the specific range;
Based on the management information that is the information managed by the power consumption information management unit and the predicted time that is the time for each mode predicted by the time prediction unit, a period in which each mode within the specific range continues A mode switching determination unit that determines a switching destination of the current mode from among the modes within the specific range using the calculated value;
A mode switching execution unit that switches the operation mode of the target device according to the determination of the mode switching determination unit;
The management information is a processing time required for a transition process from the current mode to another mode and a processing time required for a return process from the different mode to the current mode. A power-saving processing device including information that can derive a period in which each of the different modes continues according to the predicted time. A power saving processing device that switches an operation mode of a target device between a plurality of modes including a normal mode and two or more power saving modes,
A power consumption information management unit for managing information related to the operation mode switching process;
When a request for switching from the current mode of the plurality of modes to a mode within a specific range including two or more other modes is generated, each mode within the specific range is canceled when the switching request is met A time prediction unit that predicts the time until the current mode or the time until the current mode is restored for each mode within the specific range;
Based on the management information that is the information managed by the power consumption information management unit and the predicted time that is the time for each mode predicted by the time prediction unit, a period in which each mode within the specific range continues A mode switching determination unit that determines whether to switch the operation mode from the current mode to any mode within the specific range or not to switch to any one using the calculated value;
A mode switching execution unit that switches the operation mode of the target device according to the determination of the mode switching determination unit;
The management information is a processing time required for a transition process from the current mode to another mode and a processing time required for a return process from the different mode to the current mode. A power-saving processing device including information that can derive a period in which each of the different modes continues according to the predicted time.   The power saving processing apparatus according to claim 1, wherein the switching request includes a switching request when the current mode is the normal mode. The switching request is
A switching request when the current mode is the normal mode;
5. The power saving processing device according to claim 2, further comprising: a switching request when the current mode is one of the two or more power saving modes.   The power saving processing apparatus according to claim 1, wherein the mode switching determination unit performs the determination by evaluating a length of a period in which the another mode continues. The mode switching determination unit includes a power consumption required for the transition process to the different mode, a power consumption required for a period in which the different mode continues, and a power consumption required for the return process to the current mode. The above determination is made by evaluating the power consumption as the sum of
The management information includes the power consumption of the target device in each of the different modes, the power consumption of the target device required for the transition process from the current mode to each of the different modes, and the current mode from the current mode. The power consumption of the target device required for the transition process to each other mode, the processing time required for the transition process from the current mode to the other mode, and the transition from the other mode to the current mode Power consumption of the target device required for return processing, power consumption of the target device required for return processing from each other mode to the current mode, and return from each other mode to the current mode The information which can derive | lead-out the power consumption which the said mode switch determination part evaluates based on the said prediction time about each said mode among the processing time required for a process is included. 1 to the power saving processing apparatus according to any one of 6. The mode switching determination unit includes a power consumption required for the transition process to the different mode, a power consumption required for a period in which the different mode continues, and a power consumption required for the return process to the current mode. The determination is made by comparing the power consumption as the sum of the power consumption of the current mode in the same period,
The management information includes the power consumption of the target device in the current mode, the power consumption of the target device in each of the other modes, and the target required for the transition process from the current mode to each of the other modes. Power consumption of the device, power consumption of the target device required for the transition processing from the current mode to each other mode, and processing time required for the transition processing from the current mode to each other mode, , Power consumption of the target device required for return processing from each other mode to the current mode, and power consumption of the target device required for return processing from each other mode to the current mode, Based on the predicted time for each mode out of the processing time required for return processing from each of the other modes to the current mode, the mode switching determination unit performs comparison. Saving processing apparatus according to claim 1 or 2, wherein it contains information capable of deriving the power consumption to be. A timer event management unit for managing timer events;
The time prediction unit
By searching for the timer event managed by the timer event management unit, the time until the transition destination mode is canceled is predicted based on the time when the timer event is executed. The power saving processing apparatus according to claim 1, further comprising a timer event prediction unit. The timer event management unit also manages, for each timer event, device usage information indicating use or non-use of a component of the target device associated with execution of the timer event.
The management information managed by the power consumption information management unit includes device selection information indicating what is used or not used among the constituent parts of the target device in each power saving mode,
The timer event prediction unit refers to the device usage information and the device selection information, and is not used in the transition destination mode to be predicted among the timer events managed by the timer event management unit. The power saving processing device according to claim 10, wherein a time until the transition destination mode is canceled is predicted based on an execution time of a timer event that is used first by a component of the target device.   The time prediction unit, based on the time interval of each of one or more types of repetitive interrupts that occurred in the past, the time until the transition-destination mode that is the target of the prediction is canceled or the current The power saving processing apparatus according to claim 1, further comprising an iterative interrupt prediction unit that predicts a time until returning to the mode.   The repetitive interrupt prediction unit includes a measurement unit that calculates an average value of each time interval of the one or more types of repetitive interrupts that have occurred in the past, and the prediction based on each of the average values The power saving processing device according to claim 12, wherein the time until the transition destination mode is canceled or the time until the current mode is restored is predicted.   The repetitive interrupt prediction unit includes a measurement unit that calculates a latest time interval that is a latest time interval of each of the one or more types of repetitive interrupts that have occurred in the past, and each of the latest time intervals includes 13. The power saving processing apparatus according to claim 12, wherein a time required until the transition destination mode is canceled or a time required for returning to the current mode is predicted based on the prediction target. The time prediction unit manages device usage information indicating use or non-use of a component of the target device associated with execution of each of the one or more repetitive interrupts that occurred in the past;
The management information managed by the power consumption information management unit includes device selection information indicating what is used or not used among the constituent parts of the target device in each power saving mode,
The iterative interrupt prediction unit refers to the device usage information and the device selection information, and is a transition destination mode to be predicted among the one or more types of repetitive interrupts generated in the past. Based on the repetitive interrupt time interval in which the component part of the target device that is not used is used, the time until the transition destination mode is canceled or the time until the current mode is restored is predicted. The power saving processing apparatus according to any one of claims 12 to 14.   The power saving processing apparatus according to any one of claims 1 to 15, wherein the power saving processing apparatus is included in the target apparatus and targets itself for operation mode switching.   The power saving processing apparatus according to any one of claims 1 to 16, wherein the power saving processing apparatus is formed as a semiconductor integrated circuit built in a single semiconductor substrate. A power saving processing method for switching an operation mode of a target device between a normal mode and a plurality of modes including one or more power saving modes,
A power consumption information management step for managing information related to the operation mode switching process;
When a request for switching from the current mode to another mode is generated among the plurality of modes, the time until the other mode is canceled or the current mode is restored when the switching request is satisfied. A time prediction process for predicting the time until
Whether the operation mode is switched from the current mode to the other mode based on the management information that is the information managed by the power consumption information management step and the predicted time that is the time predicted by the time prediction step. A mode switching determination step for determining whether or not,
A power saving mode execution step of switching the operation mode of the target device according to the determination of the mode switching determination step,
The management information is a processing time required for a transition process from the current mode to the other mode and a processing time required for a return process from the different mode to the current mode. A power saving processing method including information capable of deriving a period in which each of the different modes continues according to the predicted time for. A power saving processing program for causing a computer to function as a power saving processing device that switches an operation mode of a target device between a plurality of modes including a normal mode and one or more power saving modes,
Power consumption information management means for managing information related to the operation mode switching process;
When a request for switching from the current mode to another mode is generated among the plurality of modes, the time until the other mode is canceled or the current mode is restored when the switching request is satisfied. Time prediction means for predicting the time until
Whether the operation mode is switched from the current mode to the other mode based on the management information that is the information managed by the power consumption information management unit and the predicted time that is the time predicted by the time prediction unit Mode switching determination means for determining whether or not,
According to the determination of the mode switching determination means, the computer is caused to function as a power saving mode execution means for switching the operation mode of the target device,
The management information is a processing time required for a transition process from the current mode to the other mode and a processing time required for a return process from the different mode to the current mode. A power-saving processing program including information that can derive a period during which each of the other modes continues according to the predicted time for.

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