JP2016203542A - Image formation apparatus, control method and program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To properly control a clock frequency in an image formation apparatus and the like having an exclusive resource that cannot be simultaneously used by a plurality of tasks.SOLUTION: An image formation apparatus which includes an exclusive resource that cannot be simultaneously used by a plurality of tasks comprises: a management part which determines tasks that can be operated in parallel on the basis of a resource used by each task and the use state of the exclusive resource, and calculates the total value of the clock frequency required by the determined tasks on the basis of the use rate of an arithmetic processing unit or clock frequency according to each task; and a control part which controls the clock frequency to be supplied to the arithmetic processing unit on the basis of the total value.SELECTED DRAWING: Figure 7

Description

  The present invention relates to an image forming apparatus, a control method, and a program.

  In an information processing apparatus such as a personal computer (PC), a technique is known in which the CPU clock frequency is dynamically changed in accordance with the current CPU usage rate in order to improve energy saving performance. This technique is also called dynamic underclocking.

  Japanese Patent Application Laid-Open No. 2004-151561 discloses a technique for calculating a CPU usage rate required for each application in a PC and changing a system clock frequency based on the calculated total CPU usage rate. The CPU usage rate required for each application is calculated from the clock frequency set for each application and the maximum clock frequency that the PC can take.

  However, the prior art has the following problems. Even if an information processing apparatus such as an image forming apparatus is receiving a large amount of data for printing via a network, for example, even if it is not necessary to increase the clock frequency, May end up and increase the clock frequency. This is because even if the user is away from the image forming apparatus or the like and the process does not need to be completed immediately, the clock frequency is increased as the current CPU usage rate increases.

  In the technique described in Patent Document 1, in the case of an image forming apparatus having an exclusive resource such as a plotter engine or a scanner engine, the clock frequency may be changed to a value larger than the actually required value. When multiple tasks using the same exclusive resource compete, the CPU clock frequency is changed based on the sum of the CPU usage rates corresponding to the multiple tasks even though they cannot actually operate in parallel. Because.

  Therefore, an object of the present invention is to appropriately control the clock frequency in an image forming apparatus having an exclusive resource that cannot be used simultaneously by a plurality of tasks.

  In an image forming apparatus that includes exclusive resources that cannot be used simultaneously by multiple tasks, a task that can be operated in parallel is determined based on the resource used by each task and the usage status of the exclusive resource, and an operation corresponding to each task A management unit that calculates a total value of clock frequencies required by the determined task based on a usage rate or a clock frequency of the processing device, and controls a clock frequency supplied to the arithmetic processing device based on the total value. A control unit.

  According to the disclosed technology, it is possible to appropriately control the clock frequency in an image forming apparatus including an exclusive resource that cannot be used simultaneously by a plurality of tasks.

1 is an overall configuration diagram of an image forming apparatus according to an exemplary embodiment. FIG. 2 is a diagram illustrating an example of a hardware configuration of an image forming apparatus according to the present embodiment. 1 is a functional configuration diagram of an image forming apparatus according to an exemplary embodiment. It is a figure which shows an example of exclusive resource management information. It is a figure which shows an example of task setting information. It is a figure which shows an example of task management information. FIG. 10 is a sequence diagram when a task of the image forming apparatus occurs. FIG. 6 is a sequence diagram at the end of a task of the image forming apparatus. It is a flowchart of the process which calculates the total value of the determination of each task which can operate | move in parallel now, and the clock frequency of CPU.

  FIG. 1 is an overall configuration diagram of an image forming apparatus 1 according to the embodiment. The image forming apparatus 1 is, for example, a multifunction peripheral (MFP) having a plurality of different types of image forming functions. The operation unit 101, the document reading unit 102, the paper feeding unit 103, and the printing unit 104 include a paper discharge unit 105. Prepare.

  The operation unit 101 displays a device status to the user and receives a request from the user. The document reading unit 102 reads a document serving as a printing source. The paper supply unit 103 supplies paper to be printed. The printing unit 104 prints the document read by the document reading unit 102 on the paper fed from the paper feeding unit 103. The paper discharge unit 105 discharges the paper printed by the printing unit 104.

  FIG. 2 is a diagram illustrating an example of a hardware configuration of the image forming apparatus 1 according to the present embodiment.

  The image forming apparatus 1 includes a scanner device 21, a plotter device 22, a drive device 23, an HDD (Hard disk drive) 24, a memory device 25, and a central processing unit (CPU) that are mutually connected by a bus B. 26, a communication interface (I / F) 27, and an operation I / F 28.

  The scanner device 21 includes a scanner, a scanner engine, an engine control unit, and the like (not shown), and scans a document to generate document data.

  The plotter device 22 includes a plotter (not shown), a plotter engine, an engine control unit, and the like, and prints document data.

  The communication I / F 27 includes a modem, a LAN (Local Area Network) card, and the like, and is used for connecting to a network.

  The operation I / F 28 is realized by a touch panel or the like having a display function, and an operation screen for operating the image forming apparatus 1 is displayed.

  When a control method according to an embodiment to be described later is realized by a program, the program is provided by, for example, distribution of the recording medium 30 or downloading from a network. The recording medium 30 is a recording medium such as a CD-ROM (Compact Disc Read Only Memory), a flexible disk, a magneto-optical disk, etc., which records information optically, electrically or magnetically, ROM (Read Only Memory), flash Various types of recording media such as a semiconductor memory that electrically records information, such as a memory, can be used.

  Further, when the recording medium 30 in which the program of the embodiment is recorded is set in the drive device 23, the program is installed from the recording medium 30 to the HDD 24 via the drive device 23. When the program is downloaded from the network, it is installed in the HDD 24 via the communication I / F 27.

  The HDD 24 stores the installed program and necessary files, data, and the like. The memory device 25 reads and stores the program from the HDD 24 when the computer is started. Then, the arithmetic processing unit 26 implements various processes as described later according to the program stored in the memory device 25.

  FIG. 3 is a functional configuration diagram of the image forming apparatus 1 according to the embodiment. The image forming apparatus 1 includes an exclusive resource management unit 11, an application execution unit 12, a task management unit 13, and a clock frequency control unit 14. Each of these units is realized by processing that one or more programs installed in the image forming apparatus 1 cause the arithmetic processing unit (CPU) 26 of the image forming apparatus 1 to execute.

  The exclusive resource management unit 11 stores exclusive resource management information 111 shown in FIG.

  FIG. 4 is a diagram illustrating an example of the exclusive resource management information 111. As described above, an “exclusive resource” is a resource that cannot be used simultaneously by a plurality of tasks. The exclusive resource management information 111 includes the usage status for each exclusive resource and the task ID being used. In the example shown in FIG. 4, the scanner engine and the plotter engine are exclusive resources, and the usage status is set as being used or unused. The task ID is identification information of a task that uses the exclusive resource. This indicates that a resource that is not managed by the exclusive resource management information 111, for example, the communication I / F 27 is not an exclusive resource. That is, tasks using the plotter engine and the scanner engine are not processed in parallel, but tasks using the communication I / F 27 are processed in parallel.

  The application execution unit 12 executes applications such as copy, printer, and facsimile (FAX). When an application task occurs, the application execution unit 12 transmits a registration request including the task ID and task name of the task to the task management unit 13. Further, when the task is completed, the application execution unit 12 transmits a deletion request including the task ID and task name of the task to the task management unit 13.

  The task management unit 13 manages the task setting information 131 shown in FIG. 5 and the task management information 132 shown in FIG.

  FIG. 5 is a diagram illustrating an example of the task setting information 131. The task setting information 131 stores a resource used by a task and a CPU usage rate for each task name (task type) such as printer printing, monochrome copying, and scanner distribution. As the CPU usage rate, for example, when a clock frequency of 1 GHz is supplied to the CPU, the CPU usage rate by the task, which is necessary for the user to feel that the processing of the task is executed without delay Set. The information stored in the task setting information 131 may be set in advance at the time of factory shipment.

  FIG. 6 is a diagram illustrating an example of the task management information 132. The task management information 132 includes task IDs and task names registered from the application execution unit 12 in the order in which tasks are processed.

  Upon receiving the task registration request from the application execution unit 12, the task management unit 13 registers the task ID and task name of the task at the end of the task management information 132 in FIG. When a task deletion request is received from the application execution unit 12, the task is deleted from the task management information 132, and the order of subsequent tasks is slid forward.

  In addition, the task management unit 13 determines all tasks that can be operated in parallel at the current time based on the task setting information 131, the task management information 132, and the exclusive resource management information 111. The task management unit 13 calculates a total value of clock frequencies required by all the determined tasks based on the CPU usage rate corresponding to each task set in the task setting information 131. The total value is output to the clock frequency control unit 14.

  The clock frequency control unit 14 controls the clock frequency supplied to the CPU based on the total value of the CPU clock frequencies input from the clock frequency determination unit 15. For example, the base clock and the clock magnification are changed to control the frequency of the clock supplied to the CPU.

  FIG. 7 is a sequence diagram of processing when a task occurs in the image forming apparatus 1.

  When an application task occurs, the application execution unit 12 transmits a registration request including the task ID and task name of the task to the task management unit 13 (step S101).

  The task management unit 13 registers the task requested to be registered by the application execution unit 12 in the task management information 132 in FIG. 6 (step S102). Then, the exclusive resource management information 111 is referred to (step S103), and the exclusive resource management information 111 is acquired from the exclusive resource management unit 11 (step S104).

  Based on the task setting information 131, task management information 132, and exclusive resource management information 111, the task management unit 13 determines all tasks that can be operated in parallel at the present time (step S105). For the determined task, the CPU usage rate set for each task in the task setting information 131 is summed, and a total value of CPU clock frequencies is calculated based on the summed value (step S106). The exclusive resource management unit 11 is requested to update the exclusive resource management information 111 (step S107).

  The exclusive resource management unit 11 updates the exclusive resource management information 111 (step S108).

  The task management unit 13 notifies the clock frequency control unit 14 of the calculated total clock frequency of the CPU (step S109).

  The clock frequency control unit 14 controls the clock frequency supplied to the CPU based on the notified value (step S110). Note that the processing of step S107 and step S109 by the task management unit 13 described above may be performed simultaneously or in the reverse order.

  When notified from the task management unit 13 in step S110 of FIG. 7, the clock frequency control unit 14 may set a certain time margin until the clock frequency is changed. For example, when the total value of the clock frequency of the CPU notified this time is smaller than the value of the clock frequency currently supplied to the CPU, until the preset period (predetermined period) elapses, the CPU A configuration may be adopted in which the clock frequency to be supplied to is not changed. As a result, for example, when the value notified from the task management unit 13 temporarily decreases and then returns to the original state because a plurality of tasks use the same exclusive resource, it takes a change in the clock frequency. Loss of time can be eliminated. On the other hand, when the total value of the clock frequencies of the CPU notified this time exceeds the value of the clock frequency currently supplied to the CPU, the clock frequency supplied to the CPU may be changed immediately.

  The clock frequency control unit 14 may select the following mode when changing the clock frequency of the CPU. For example, when the total value of the clock frequencies notified from the task management unit 13 exceeds the first threshold (for example, 500 MHz) continuously for a preset first period (for example, 3 seconds), the normal mode is set. The first clock frequency (for example, 800 MHz) is changed. Further, a second threshold value (for example, 300 MHz) smaller than the first threshold value is continuously provided for a second period (for example, 5 seconds) in which the notified total value of the clock frequencies is longer than the first period. When the frequency is lower, the eco mode may be changed to a second clock frequency (for example, 400 MHz) smaller than the first clock frequency. Thereby, it is possible to reduce a loss of time required for switching the clock frequency of the CPU by the clock frequency control unit 14. Further, when the clock frequency is increased, the clock frequency is switched more rapidly than when the clock frequency is decreased, so that the user can feel that the task processing is executed without delay.

  FIG. 8 is a sequence diagram of processing at the time of task deletion in the image forming apparatus 1.

  When the application task ends, the application execution unit 12 requests the task management unit 13 to delete the task (step S201).

  Based on the received task ID, the task management unit 13 deletes the task requested to be deleted from the application execution unit 12 from the task management information 132 in FIG. 6 (step S202). In addition, the exclusive resource management unit 11 is notified of the task ID of the task requested to be deleted (step S203). The exclusive resource management unit 11 changes the usage status of the exclusive resource whose used task ID matches the received task ID to “unused” in the exclusive resource management information 111 of FIG. 4 (step S204). ).

  Next, in steps S <b> 205 to S <b> 212, for each task registered in the task management information 132, each task that can operate in parallel at this time is determined based on the task setting information 131, task management information 132, and exclusive resource management information 111. The CPU clock frequency is controlled. Steps S205 to S212 are the same as the processes of steps S103 to S110 shown in FIG.

  FIG. 9 is a flowchart of processing for determining each task that can operate in parallel at the present time and calculating a total value of the CPU clock frequencies. Details of the processing in steps S105 and S106 of FIG. 7 by the task management unit 13 will be described with reference to FIG.

  First, the task management unit 13 acquires the task ID and task name of the first task from the task management information 132 in FIG. 6 (step S301). Next, based on the acquired task name, the resource used by the task and the CPU usage rate set for the task are acquired from the task setting information 131 of FIG. 5 (step S302). Next, the exclusive resource management unit 11 acquires the usage status of each exclusive resource used by the task in the exclusive resource management information 111 of FIG. 4 (step S303). It is determined whether the usage status of the exclusive resource used by the task is “unused” (step S304). When two or more exclusive resources are required as in the copy task of FIG. 5, it is determined whether all the exclusive resources are “unused”.

  If it is not “unused” (NO in step S304), the task cannot be processed using the exclusive resource, and the process advances to step S307 to determine whether the next task is registered. On the other hand, if it is determined that it is “unused” (YES in step S304), the usage status of this exclusive resource is updated to “in use” and the task ID of the task is set as the task ID being used. (Step S305). And the said task is memorize | stored as a task which can operate | move in parallel now (step S306).

  Then, it is determined whether or not the next task is registered in the task management information 132 of FIG. 6 (step S307). If not registered (NO in step S307), the CPU usage rate set for each task that can operate in parallel is summed, and the total value of the CPU clock frequencies is calculated based on the summed value (step S308). ), The process is terminated. If the next task is registered (YES in step S307), the next task is acquired from the task management information 132 in FIG. 6 (step S309). Then, the process returns to step S302.

  4 to 6, first, the “printer printing” task at the top of FIG. 6 is acquired, and among the “plotter engine” and “communication I / F” resources used by the task, “plotter” is used. The usage status of “engine” is set to “in use”. Then, the “printer printing” task is stored as a task that can be operated in parallel at the present time.

  Next, the “monochrome copy” task in the next order in FIG. 6 is acquired. Among the resources of the “scanner engine” and “plotter engine” used by the task, the usage status of the “plotter engine” is “in use”, so the “monochrome copy” task cannot operate in parallel at this time. Judge.

  Next, the “scanner distribution” task in the next order in FIG. 6 is acquired. Among the resources of “scanner engine” and “communication I / F” used by the task, the usage status of “scanner engine” is “unused”, so the usage status is set to “in use”. . The “scanner distribution” task is stored as a task that can be operated in parallel at the present time.

  Next, the “FAX reception” and “FAX transmission” tasks in the next order in FIG. 6 are sequentially acquired, and the same processing is performed. Since the usage status of the “plotter engine” and the “scanner engine” is “in use”, it is determined that the “FAX reception” and “FAX transmission” tasks cannot be operated in parallel at the present time.

  Then, in the task setting information 131 of FIG. 5, the CPU usage rates of 15% and 20% of the “printer printing” task and the “scanner distribution” task that can be operated in parallel at the present time are totaled. In the example of FIG. 5, the CPU usage rate set for each task is set as the CPU usage rate necessary for processing of each task when the clock frequency of the CPU is 1 GHz, for example. Therefore, 35 MHz, which is the sum of 15% and 20%, multiplied by 1 GHz, 350 MHz is calculated as the total CPU clock frequency required by each task that can operate in parallel at the present time. To do.

  In addition, in order to give a margin to the CPU, a predetermined value (for example, 25%) may be added to the total CPU usage rate set for each task. In that case, the total value of the CPU clock frequency for operating each task in parallel is calculated as 600 MHz by multiplying 60%, which is the sum of 15%, 20% and 25%, by 1 GHz. To do.

  Note that the value of the clock frequency multiplied by the CPU usage rate registered in the task setting information 131 of FIG. 5 may be changed by setting. Accordingly, when the CPU is replaced with one that can operate at, for example, 2 GHz, the value of the clock frequency multiplied by the CPU usage rate is set to 2 GHz, so that the information of the task setting information 131 in FIG. 5 does not have to be updated. Can be operated at higher speed.

<Effect>
According to the method and configuration of the embodiment, when a plurality of tasks use the same exclusive resource and cannot be operated in parallel, power consumption can be reduced by appropriately controlling the clock frequency. For example, it is assumed that a printer application and a copy application each register a task and cannot operate in parallel because the use of the plotter engine competes. When the plotter engine is assigned to the task of the printer application, the task of the copy application cannot be operated, and only the CPU usage rate by the printer application task is set as the current CPU usage rate. As a result, it is possible to perform control so as not to increase the CPU clock frequency unnecessarily.

  For example, when one task receives a large amount of data for printing via the network, it is based on the CPU usage rate set in association with the one task, not the current CPU usage rate. To control the clock frequency of the CPU. Therefore, it is possible to prevent the clock frequency from being increased unnecessarily.

  Instead of setting the task name, the resource to be used, and the CPU usage rate of each task in the task setting information 131 in advance, in step S101 in FIG. It is good also as a structure which notifies information. In this case, the task management unit 13 may record the task name, the resource to be used, and the CPU usage rate in association with the task ID in the task management information.

  In the above-described embodiment, the CPU usage rate required by each task when the CPU operates at a predetermined clock frequency (for example, 1 GHz) is set in the task setting information 131 in FIG. Based on the above, the CPU clock frequency is calculated. However, instead of the CPU usage rate, the clock frequency required by each task may be registered. In that case, the sum of the clock frequencies required for each set task may be supplied to the CPU.

  The image forming apparatus 1 is not limited to a multifunction peripheral (MFP), and may be a device such as a copy, a facsimile, or a printer.

  The functions (exclusive resource management unit 11, application execution unit 12, task management unit 13, and clock frequency control unit 14) of each unit of the image forming apparatus 1 described above are calculated by the arithmetic processing unit (CPU or processor) 26, for example, the HDD 24. It can be realized by executing a program stored in the memory device 25 (including ROM, flash memory, etc.), the recording medium 30 and the like. However, the present invention is not limited to this, and at least a part of the functions of each unit of the image forming apparatus 1 may be realized by a dedicated hardware circuit (for example, a semiconductor integrated circuit). For example, a semiconductor integrated circuit such as an FPGA (Field Programmable Gate Array) or an ASIC (Application Specific Integrated Circuit) may be used for the clock frequency control unit 14. Alternatively, at least a part of the clock frequency control unit 14 may be configured by an oscillator, a variable frequency generation circuit, or a multiplication circuit. At least a part of the task management unit 13 may be realized by an analog or digital logic circuit.

  It should be noted that the system configuration in the above-described embodiment is an example, and it goes without saying that there are various system configuration examples depending on the application and purpose.

DESCRIPTION OF SYMBOLS 1 Image forming apparatus 11 Exclusive resource management part 111 Exclusive resource management information 12 Application execution part 13 Task management part (an example of a "management part")
131 Task setting information 132 Task management information 14 Clock frequency control unit (an example of “control unit”)

Japanese Patent No. 4517006

Claims (9)

In an image forming apparatus provided with an exclusive resource that cannot be used simultaneously by a plurality of tasks,
Based on the resource used by each task and the usage status of the exclusive resource, a task that can be operated in parallel is determined, and the determined task is determined based on the usage rate or clock frequency of the arithmetic processing device corresponding to each task. A management unit that calculates the total value of the clock frequencies required by
A control unit for controlling a clock frequency supplied to the arithmetic processing unit based on the total value;
An image forming apparatus comprising: The management unit manages the resource used by the task of the type in association with the type of the task, and the usage rate or clock frequency of the arithmetic processing unit set for the task of the type,
The image forming apparatus according to claim 1. The management unit
When making the decision, update the usage status of the exclusive resource;
The image forming apparatus according to claim 1. The controller is
When the total value is smaller than the value of the current clock frequency supplied to the arithmetic processing unit, the clock frequency supplied to the arithmetic processing unit is not changed until a predetermined period has elapsed.
The image forming apparatus according to claim 1. The controller is
When the total value exceeds the first threshold value continuously for the first period, the clock frequency supplied to the arithmetic processing unit is changed to the first clock frequency, and the total value is the first period. The clock frequency supplied to the arithmetic processing unit is lower than the first clock frequency when continuously falling below the second threshold value which is smaller than the first threshold value for the second period having the above length. Change to a smaller second clock frequency,
The image forming apparatus according to claim 1. The management unit
Making the determination when the task occurs and when the task is terminated;
The image forming apparatus according to claim 1. The exclusive resource is
A scanner engine or plotter engine,
The image forming apparatus according to claim 1. A control method in an image forming apparatus including an exclusive resource that cannot be used simultaneously by a plurality of tasks,
Based on the resource used by each task and the usage status of the exclusive resource, a task that can be operated in parallel is determined, and the determined task is determined based on the usage rate or clock frequency of the arithmetic processing device corresponding to each task. Calculating the total clock frequency required by
Controlling a clock frequency supplied to the arithmetic processing unit based on the total value;
A control method comprising: A program for causing an image forming apparatus including an exclusive resource that cannot be used simultaneously by a plurality of tasks to perform the following processing:
Based on the resource used by each task and the usage status of the exclusive resource, a task that can be operated in parallel is determined, and the determined task is determined based on the usage rate or clock frequency of the arithmetic processing device corresponding to each task. Processing to calculate the total clock frequency required by
A process of controlling a clock frequency supplied to the arithmetic processing unit based on the total value;
A program that executes

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