JP2002182776A - System and method for controlling operating frequency - Google Patents

Abstract

PROBLEM TO BE SOLVED: To appropriately control the operating frequency of a processor. SOLUTION: A timing detecting part 22 detects task switching timing, the performance start/end timing of interrupt processing and timing when a predetermined time Tmon elapses. A load quantity detecting part 20 performs processing for detecting the load quantity of the processor by accumulating the count value (tick value) of a tick counter when the timing detecting part 22 detects the task switching timing and the performance start/end timing of the interrupt processing. A frequency switching controlling part 21 performs processing for automatically switching operation frequencies in accordance with the use situation of the processor when the timing detecting part 22 detects that the predetermined time Tmon has elapsed by a performance monitor timer 30.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an operating frequency control system and an operating frequency control method for controlling the operating frequency of a processor, and more particularly to an operating frequency control system and an operating frequency control system capable of appropriately switching the operating frequency of a processor. The present invention relates to an operating frequency control method.

[0002]

2. Description of the Related Art Cellular phones and PDAs (Personal Digital
Assistant), CPU (Central Processing Unit) and MPU for portable information processing terminals such as notebook computers
A processor such as a (MicroProcessing Unit) can be driven by receiving power from a rechargeable battery (secondary battery) or the like.

As a technique for reducing the power consumption of a processor for such a portable information processing terminal, there is known an operating frequency control system for dynamically controlling the operating frequency of the processor. This operating frequency control system is realized, for example, by a processor activating an OS (Operating System, hereinafter referred to as OS).

[0004] The processing speed and power consumption of a processor change by switching the operating frequency, as shown in FIG. 17, for example. Therefore, the operating frequency control system reduces the operating frequency when executing an application having a light load, such as a program for displaying telephone directory data, e-mail data, or a still image, for example, to reduce power consumption. Reduce the amount. On the other hand, the operating frequency control system increases the operating frequency when executing a heavy-load application such as a program for playing a moving image or audio so that the user does not feel uncomfortable. Control.

In order to realize such a function, conventionally,
For example, an application including a process with a large processing amount and including a heavy load on a processor is associated with a frequency control operation, and the operation frequency of the processor is changed at the time of starting and ending the execution of the application.

For example, as shown in FIG. 18, the conventional operating frequency control system supplies the magnitude of the voltage to be supplied to the processor during a normal operation when a high load application including a process that places a heavy load on the processor is executed. The voltage is changed to a value different from that of the operating voltage, and the operating frequency is increased.

[0007]

In the above-mentioned prior art, the operating frequency of the processor is controlled to be switched only at the start and end of the execution of an application including a process that places a heavy load on the processor. For this reason, for example, when a large number of applications with a small processing amount are executed, there is a problem that the operating frequency cannot be appropriately switched despite the increase in the load on the processor.

[0008] Even during the execution of one application, the load on the processor may change with time, such as the timing when a large number of interrupt processes occur and the timing when the interrupt process does not occur often. In such a case, the conventional operating frequency control system maintains the same operating frequency during the execution of the application, and cannot appropriately control the operating frequency in accordance with the actual use situation of the processor.

The present invention has been made in view of the above situation, and has as its object to provide an operating frequency control system and an operating frequency control method capable of appropriately controlling the operating frequency of a processor.

[0010]

In order to achieve the above object, an operating frequency control system according to a first aspect of the present invention is for automatically switching an operating frequency of a processor. Timing detecting means for detecting a first timing arriving every time elapses,
When the first timing is detected by the timing detecting means, a frequency control means is provided for specifying a use state of the processor and switching an operating frequency of the processor according to the specified use state.

According to the present invention, when the first timing which arrives every time a predetermined time elapses is detected by the timing detecting means, the frequency control means specifies the use state of the processor and switches the operating frequency. be able to. As a result, the operating frequency of the processor can be controlled so as to be appropriately switched in accordance with the usage state of the processor.

[0012] More specifically, there is provided a load amount detecting means for detecting a load amount of the processor, wherein the timing detecting means detects a second timing included in a predetermined time until the first timing arrives. Then, the load amount detecting unit is instructed to execute a process for detecting a load amount of the processor, and the frequency control unit is configured to use the processor usage state based on the load amount of the processor detected by the load amount detecting unit. It is desirable to specify the operating frequency and switch the operating frequency of the processor.

For example, it is desirable that the timing detecting means detects, as the second timing, the switching timing of the task executed by the processor and the execution start timing and the execution end timing of the interrupt processing.

It is preferable that the load amount detecting means detects the load amount of the processor by integrating the tick values spent for the processing executed by the processor.

[0015] The frequency control means may switch an operating frequency of the processor in accordance with an instruction from a user program executed by the processor.

A storage unit for storing data in which a load amount of the processor is associated with an operating frequency, wherein the frequency control unit refers to the data stored in the storage unit and reads the load amount detection unit It is desirable to specify the operating frequency corresponding to the load amount of the processor detected by the above and switch the operating frequency of the processor.

The power supply for supplying a power supply voltage to the processor and power supply control means for controlling the magnitude of the power supply voltage supplied from the power supply to the processor are provided. Is stored together with data that associates the load of the processor with the operating frequency, and the frequency control unit refers to the data stored in the storage unit, and the load amount detection unit The magnitude of the supply voltage corresponding to the load amount of the processor detected by the power supply is specified, and the magnitude of the power supply voltage supplied from the power supply to the processor is controlled by the power supply control means to the magnitude of the specified supply voltage. It is desirable to make it.

An operating frequency control system according to a second aspect of the present invention is for automatically switching an operating frequency of a processor. The operating frequency control system monitors a load of the processor at a predetermined timing. Each time the time elapses, the processor usage status is specified based on the monitored load amount, and the operating frequency of the processor is switched according to the specified usage status.

According to the present invention, the processor utilization is specified by monitoring the processor load,
The operating frequency of the processor can be switched according to the specified use situation. As a result, the operating frequency of the processor can be controlled so as to be appropriately switched in accordance with the usage state of the processor.

The operating frequency of the processor may be switched according to an instruction from a user program executed by the processor.

An operating frequency control method according to a third aspect of the present invention is a method for automatically switching the operating frequency of a processor. Each time elapses, the usage status of the processor is specified based on the monitored load amount, and the operating frequency of the processor is switched according to the specified usage status.

The operating frequency of the processor may be switched according to an instruction from a user program executed by the processor.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an operating frequency control system according to an embodiment of the present invention will be described in detail with reference to the drawings, taking a case where the present invention is applied to a portable information processing terminal 100 as an example.

The portable information processing terminal 100 includes, for example,
Mobile phones, PDAs (Personal Digital Assistants),
It is a terminal device such as a notebook personal computer that can operate even when disconnected from a commercial power supply, and has a configuration as shown in FIG. As shown, the portable information processing terminal 100 includes a processor 1 and a ROM (Read Only Memory).
y) 2, RAM (Random Access Memory) 3, input unit 4, display control unit 5, display unit 6, power supply control unit 7
And a power supply 8.

The processor 1 is, for example, a CPU (Central
Processing Unit) or MPU (Micro Processin)
g Unit), etc., and the portable information processing terminal 100
This is for controlling the entire operation. Processor 1
Reads a program recorded in, for example, the ROM 2 under the control of an OS (Operating System) and executes various applications. Note that the processor 1 may read a program from an arbitrary recording medium such as a magnetic disk device (not shown) and execute an application or the like. Further, the processor 1 includes a tick counter 10 that counts up for each tick. Here, one tick corresponds to one tick supplied to the processor 1.
One clock signal. That is, the tick counter 10 counts up, for example, by counting the number of clocks at the timing of the rising edge of the clock signal supplied to the processor 1.

The ROM 2 is a read-only storage circuit for storing a device driver, a loader program, an OS, an application program, and the like. ROM2 is
An operating frequency data table 11 as illustrated in FIG. 2A is stored.

The operating frequency data table 11 stores the operating frequency to be set for the processor 1 and the voltage to be supplied to the processor 1 based on the task executed by the processor 1 within a predetermined period and the tick value used for interrupt processing. It contains data for specifying the size of For example, the operating frequency data table 11 includes “operating frequency” indicating an operating frequency that can be set for the processor 1, “TICKmax” indicating a maximum tick value, and “TICKm” indicating a minimum tick value.
in "and data such as" supply voltage "indicating the magnitude of the supply voltage to the processor 1.

The RAM 3 is a rewritable storage circuit that provides a work area when the processor 1 executes a program and enables temporary storage of data and the like. For example, the RAM 3 stores an operating frequency request management table 12 as illustrated in FIG.

The operating frequency request management table 12 is a table for managing the operating frequency requested by the user program executed by the processor 1, and includes a management number for identifying the operating frequency for each request from the user program. The data includes a “management number” indicating the requested operation frequency and a “requested frequency” indicating the requested operation frequency.

The input unit 4 includes, for example, a keypad, a mouse,
The portable information processing terminal 100 is constituted by a pointing device or the like, and is used to input instruction information for instructing the operation of the portable information processing terminal 100, data indicating characters and numerals, and the like.

The display control unit 5 includes, for example, a VRAM (Video-
RAM), an LCD (Liquid Crystal Display) driver, and the like, for controlling the operation of the display unit 6 in accordance with image data and the like received from the processor 1.

The display unit 6 is composed of, for example, an LCD panel or the like, and displays an image or the like under the control of the display control unit 5.

The power supply control section 7 is composed of, for example, a switching regulator and the like, and regulates the power supply voltage supplied from the power supply 8 to a predetermined voltage value and supplies it to the processor 1 and the like. Here, the power supply control unit 7 adjusts the supplied power by changing the magnitude of the voltage supplied to the processor 1 to enable control of the operating frequency. When the portable information processing terminal 100 is connected to a charging device (not shown), the power control unit 7 notifies the processor 1 that the portable information processing terminal 100 has been set to the charging device, and starts charging the power source 8. On the other hand, when the connection between the portable information processing terminal 100 and the charging device is released, the power control unit 7 notifies the processor 1 of that fact.
And the charging of the power supply 8 ends.

The power supply 8 is composed of a rechargeable battery (secondary battery) such as a lithium ion battery or a nickel hydride ion battery, for supplying power for driving the portable information processing terminal 100. is there.

Next, a logical configuration of the operating frequency control system 101 realized by the processor 1 activating the OS in the portable information processing terminal 100 having the above configuration will be described with reference to FIG. As shown in the drawing, the operating frequency control system 101 includes a load amount detection unit 20.
, Frequency switching control unit 21 and timing detection unit 22
, A monitor flag 23, and an operation mode setting processing unit 24.

The load amount detecting section 20 includes a tick counter 1
A process for detecting the load amount applied to the processor 1 using the count value of 0 is executed. For example, the load amount detection unit 20 obtains a tick value required for a task executed within a certain period of time or an interrupt process by integrating the count value (tick value) of the tick counter 10 and a variable Tota.
Set as l_ticks. Here, the load amount detection unit 20
Is a variable Tick indicating the count value of the tick counter 10.
Using _Reg_OLD and the variable Tick_Reg, a process for integrating the count value is executed.

The variable Tick_Reg_OLD indicates the count value of the tick counter 10 at the timing when the processor 1 switches the processing to the task currently being executed or when the execution of the interrupt processing is started. Also, the variable Tick_Reg is
This shows the current count value of the tick counter 10.

The frequency switching control unit 21 includes a load amount detection unit 2
Switching of the operating frequency of the processor 1 is controlled based on the variable Total_ticks set by 0. When switching the operating frequency of the processor 1, the frequency switching control unit 21 instructs the power supply control unit 7 to switch the magnitude of the power supply voltage supplied to the processor 1. At this time, the frequency switching control section 21 refers to the operating frequency data table 11 stored in the ROM 2 and specifies the magnitude of the power supply voltage supplied from the power supply control section 7 to the processor 1.

The timing detecting section 22 has a performance monitor timer 30, and detects the timing at which the load amount detecting section 20 and the frequency switching control section 21 execute various processes. That is, when the timing detection unit 22 detects the switching timing of the task to be executed by the processor 1 and the execution start / end timing of the interrupt processing, the timing detection unit 22 executes the processing for integrating the count value of the tick counter 10 into a load. It instructs the amount detection unit 20. In addition, the timing detection unit 22 determines a predetermined time T
Performance monitor timer 3 that _mon has passed
0, the processing for automatically switching the operating frequency in accordance with the usage status of the processor 1 is executed.
It instructs the frequency switching control unit 21.

The performance monitor timer 30 detects that a predetermined time T _{mon, which} is a cycle for evaluating the use state of the processor 1, has elapsed. The performance monitor timer 30 changes the operating frequency according to the use state of the processor 1. It is reset every time the processing for switching is executed, and the measurement of the elapsed time is started again (restarted).

The monitor flag 23 indicates that the portable information processing terminal 1
00 indicates whether or not the operation mode is an operation mode in which the operation frequency is automatically switched according to the use state of the processor 1. That is, the monitor flag 23 indicates that the portable information processing terminal 100 is in an operation mode (performance monitor mode M2 described below) in which the load of the processor 1 is monitored and the operation frequency is automatically switched.
The monitor flag 23 is set to "ON when the processor 1 is in an operation mode (fixed frequency operation mode M3 described later) for operating the processor 1 at an operation frequency in accordance with an instruction from a user program executed by the processor 1.
OFF ".

The operation mode setting processing section 24 sets the operation mode of the portable information processing terminal 100 by executing a predetermined initialization process when the power supply 8 is turned on.

The operation of portable information processing terminal 100 according to the embodiment of the present invention will be described below.

FIG. 4 is a diagram showing an operation mode of the portable information processing terminal 100. As shown in the figure, this portable information processing terminal 100 has a performance monitor mode M2 and a fixed frequency operation mode M3 in addition to a power-off mode M1.
And

The performance monitor mode M2 is an operation mode in which the usage of the processor 1 is monitored by monitoring the load, and the operating frequency can be automatically switched according to the specified usage.

The fixed frequency operation mode M3 is an operation mode in which the processor 1 operates at an operation frequency according to an instruction from a user program executed by the processor 1.

In the portable information processing terminal 100, when the power supply 8 is turned on, the operating frequency control system 101 is activated, and the operation mode is set by the operation mode setting processing unit 24.

That is, the operation mode setting processing unit 24
In the power-off mode M1, for example, an instruction to turn on the power supply 8 is received based on instruction information input from the input unit 4.
At this time, the operation mode setting processing unit 24 sets the operation mode of the portable information processing terminal 100 to the performance monitor mode M2 by executing the performance monitor initialization processing shown in the flowchart of FIG. Alternatively, the operation mode setting processing unit 24 sets the operation mode of the portable information processing terminal 100 to the fixed frequency operation mode M3 by executing the fixed frequency operation initialization processing shown in the flowchart of FIG.

The operation mode setting processing section 24 performs, for example, based on the instruction information input from the input section 4 when the power supply 8 is instructed, the operation mode when the power supply 8 was last turned off, and the like. 5 or the fixed frequency operation initialization shown in the flowchart of FIG.

The performance monitor initialization processing shown in the flowchart of FIG. 5 will be described below.

When the performance monitor initialization processing section 24 starts the performance monitor initialization processing,
Is determined to be “OFF” (step S
1).

When the operation mode setting processor 24 determines that the monitor flag 23 is "ON" (NO in step S1), it determines that the operation mode of the portable information processing terminal 100 is already in the performance monitor mode M2. ,
The performance monitor initialization processing ends as it is.

On the other hand, when the operation mode setting processor 24 determines that the monitor flag 23 is “OFF” (YES in step S 1), the load amount detector 20 integrates the count value of the tick counter 10. Variable Tota used for
Initialize l_ticks as zero (step S2).

The operation mode setting processing unit 24 initializes the variables Tick_Reg and Tick_Reg_OLD used by the load amount detection unit 20 and the frequency switching control unit 21 by similarly setting them to zero (step S3).

Further, the operation mode setting processing section 24 resets the performance monitor timer 30 and starts measuring the elapsed time (step S4).

After that, the operation mode setting processing section 24
The mobile information processing terminal 1 with the monitor flag 23 set to “ON”
The operation mode of 00 is set to the performance monitor mode M2 (step S5), and the performance monitor initialization processing ends.

Next, the fixed frequency operation initialization processing shown in the flowchart of FIG. 6 will be described.

When the operation mode setting processing section 24 starts the fixed frequency operation initialization processing, the monitor flag 23 is set to "O".
N ”is determined (step S10).

When the operation mode setting processor 24 determines that the monitor flag 23 is "ON" (step S10).
YES), the measurement of the elapsed time by the performance monitor timer 30 is stopped (step S11).

The operation mode setting processing section 24 sets the monitor flag 23 to “OFF” and sets the portable information processing terminal 10
The operation mode of 0 is set to the fixed frequency operation mode M3 (step S12).

If the operation mode setting processing section 24 determines in step S10 that the monitor flag 23 is "OFF" (NO in step S10), the processing in steps S11 and S12 is skipped.

After that, the operation mode setting processing section 24
The operation frequency request management table 12 stored in the RAM 3 is initialized (step S13), and the fixed frequency operation initialization processing ends.

When the operation mode of the portable information processing terminal 100 is the performance monitor mode M2, the operation mode setting processing section 24 executes the fixed frequency operation initialization processing to change the operation mode to the fixed frequency operation mode. Set to M3. Alternatively, when the operation mode of the portable information processing terminal 100 is the fixed frequency operation mode M3, the operation mode setting processing unit 24 sets the operation mode to the performance monitor mode M2 by executing a performance monitor initialization process. .

When power supply 8 is turned on in portable information processing terminal 100, operating frequency control system 101
The timing detection unit 22 detects task switching timing, execution start / end timing of interrupt processing, and timing at which a predetermined time T _mon has elapsed.

When detecting the task switching timing and the execution start / end timing of the interrupt processing, the timing detection section 22 instructs the load amount detection section 20 to execute the Total_ticks integration processing shown in the flowchart of FIG. This Tota
The l_ticks integration process is a process for detecting the load of the processor 1 by integrating the count value of the tick counter 10.

The Tota shown in the flowchart of FIG.
The l_ticks integration processing will be described.

The load detecting section 20 includes a timing detecting section 2
When the Total_ticks integration process is started in response to the instruction from the second unit 2, it is determined whether or not the monitor flag 23 is "ON" (step S20).

The load amount detecting section 20 has a monitor flag 23
Is determined to be "OFF" (NO in step S20), the Total_ticks integration processing ends.

On the other hand, when determining that the monitor flag 23 is "ON" (YES in step S20), the load amount detecting section 20 executes a process for setting a variable Total_ticks (step S21). That is, the load amount detection unit 20 newly sets a value obtained by adding the current value of the variable Total_ticks to the value obtained by subtracting the variable Tick_Reg_OLD from the variable Tick_Reg as the variable Total_ticks. As a result, the tick value corresponding to the load amount of the processor 1 is added to the variable Total_ticks, and the usage state of the processor 1 can be specified.

After setting the current value of the variable Tick_Reg as a new variable Tick_Reg_OLD (step S22), the load amount detection unit 20 ends the Total_ticks integration processing.

When the performance monitor / timer 30 detects that the predetermined time T _mon has elapsed, the timing detection section 22 executes the operation frequency automatic switching processing shown in the flowchart of FIG. An instruction is given to the control unit 21. The operation frequency automatic switching process is a process for automatically switching the operation frequency in accordance with the usage status of the processor 1.

The operation frequency automatic switching process shown in the flowchart of FIG. 8 will be described below.

When starting the operating frequency automatic switching process in response to the instruction from the timing detecting unit 22, the frequency switching control unit 21 determines whether the processor 1 is currently executing a task (step S30). .

When determining that the task is being executed (YES in step S30), frequency switching control unit 21 executes a process for setting variable Total_ticks (step S31). That is, the frequency switching control unit 21 newly adds the current value of the variable Total_ticks to the value obtained by subtracting the variable Tick_Reg_OLD from the variable Tick_Reg,
Set as al_ticks.

On the other hand, if frequency switching control unit 21 determines that processor 1 is not executing a task (NO in step S30), it skips the processing in step S31.

Thereafter, the set frequency F _cpu to be newly set as the operating frequency of the processor 1 is specified (step S32). At this time, the frequency switching control unit 21
With reference to the operating frequency data table 11 stored in 2, the operating frequency of the processor 1 that matches the tick value indicated by the variable Total_ticks is specified. That is, the frequency switching control unit 21 stores the data “TICKmax” and “TICKmin” included in the operating frequency data table 11 and the variable Total_
The ticks are compared with each other, and data “operating frequency” corresponding to a case where the condition shown in Expression 1 is satisfied is specified as the set frequency F _cpu .

[Equation 1] TICKmin ≦ Total_ticks <TICKmax

The frequency switching control section 21 determines whether or not the specified set frequency F _cpu is higher than the current operating frequency of the processor 1 (step S33).

The frequency switching control section 21 sets the set frequency F
_If it is determined that _cpu is higher than the current operating frequency (YES in step S33), an operating frequency clock-up process described later is executed (step S34), and the processor 1
Clock up the operating frequency of The clock signal defining the operating frequency of the processor 1 is different from the clock signal for counting up by the tick counter 10 and is supplied to each part of the portable information processing terminal 100.

On the other hand, when frequency switching control unit 21 determines that set frequency F _cpu is equal to or lower than the current operating frequency (NO in step S33), set frequency F _cpu is lower than the current operating frequency in processor 1. It is determined whether or not this is the case (step S35).

The frequency switching control section 21 sets the set frequency F
_If it is determined that _cpu is smaller than the current operating frequency (YES in step S35), an operating frequency clock down process described later is executed (step S36), and the processor 1
Clock down the operating frequency of

On the other hand, if frequency switching control section 21 determines that set frequency F _cpu is equal to the current operating frequency (NO in step S35), it skips the processing in step S36.

After that, the frequency switching control section 21
Initialize with Total_ticks set to zero (step S3
7).

The frequency switching control section 21 sets the variable Tick
Similarly, the _Reg and the variable Tick_Reg_OLD are also initialized to zero (step S38).

The frequency switching control unit 21 resets the performance monitor timer 30, starts (restarts) the measurement of the elapsed time again (step S39), and ends the operation frequency automatic switching process.

Next, the operating frequency clock-up processing executed by the frequency switching control section 21 in step S34 of the above-described automatic operating frequency switching processing will be described with reference to the flowchart of FIG.

When starting the operating frequency clock-up processing, the frequency switching control section 21 determines whether or not the set frequency F _cpu is different from the current operating frequency in the processor 1 (step S40).

The frequency switching control unit 21 sets the set frequency F
_CPU is not different from current operating frequency, ie
If it is determined that the set frequency F _cpu matches the current operating frequency (NO in step S40), the operating frequency clock-up process ends.

On the other hand, when frequency switching control section 21 determines that set frequency F _cpu is different from the current operating frequency (YES in step S40), supply to processor 1 corresponding to set frequency F _cpu is provided. The voltage value _Vcc is specified (Step S41). At this time, the frequency switching control unit 2
1 refers to the operating frequency data table 11 stored in the ROM 2 and specifies the magnitude of the voltage supplied to the processor 1 corresponding to the set frequency F _cpu . That is,
The frequency switching control unit 21 operates the operating frequency data table 1
1 of the data “supply voltage” included in the set frequency F
_The data corresponding to the data “operating frequency” specified as the _cpu is specified as the supply voltage value _Vcc .

The frequency switching control section 21 determines whether or not the specified supply voltage value _Vcc is different from the magnitude of the voltage currently supplied from the power supply control section 7 to the processor 1 (step S42).

The frequency switching control section 21 supplies the supply voltage _Vcc
Is different from the current supply voltage (YES in step S42), the power supply controller 7 is controlled to change the magnitude of the voltage supplied to the processor 1 in accordance with the supply voltage value _Vcc. (Step S43).

On the other hand, the frequency switching control unit 21 determines that the supply voltage value V _cc is not different from the current supply voltage value, that is, the supply voltage value V _cc matches the current supply voltage value. When it is determined (N in step S42)
O), the process of step S43 is skipped.

Thereafter, the frequency switching control unit 21 clocks up by changing the operating frequency of the processor 1 in accordance with the set frequency F _cpu (step S44).
The operation frequency clock up process ends.

Next, the operating frequency clock down processing executed by the frequency switching control section 21 in step S36 of the above-described automatic operating frequency switching processing will be described with reference to the flowchart of FIG.

When the operating frequency clock down process is started, the frequency switching control section 21 determines whether or not the set frequency F _cpu is different from the current operating frequency of the processor 1 (step S50).

The frequency switching control unit 21 sets the set frequency F
_CPU is not different from current operating frequency, ie
If it is determined that the set frequency F _cpu matches the current operating frequency (NO in step S50), the operating frequency clock down process ends.

On the other hand, when frequency switching control section 21 determines that set frequency F _cpu is different from the current operating frequency (YES in step S50), supply to processor 1 corresponding to set frequency F _cpu is performed. The voltage value _Vcc is specified (step S51). At this time, the frequency switching control unit 2
1 refers to the operating frequency data table 11 stored in the ROM 2 and specifies the magnitude of the voltage supplied to the processor 1 corresponding to the set frequency F _cpu . That is,
The frequency switching control unit 21 operates the operating frequency data table 1
Among the data “supply voltage” stored in 1, the one corresponding to the data “operating frequency” specified as the set frequency F _cpu is specified as the supply voltage value _Vcc .

At this time, the frequency switching control unit 21
The clock is reduced by changing the operating frequency of the processor 1 in accordance with the set frequency F _cpu (step S5).
2).

Thereafter, the frequency switching control unit 21 sends the specified supply voltage value _Vcc from the power supply control unit 7 to the processor 1.
It is determined whether or not the current voltage is different from the magnitude of the voltage currently supplied (step S53).

The frequency switching control section 21 supplies the supply voltage _Vcc
Is different from the current supply voltage (YES in step S53), the power supply control unit 7 is controlled to change the magnitude of the voltage supplied to the processor 1 in accordance with the supply voltage value _Vcc. Then (step S54), the operation frequency clock down process ends.

On the other hand, the frequency switching control unit 21 determines that the supply voltage value V _cc is not different from the current supply voltage value, that is, the supply voltage value V _cc matches the current supply voltage value. When it is determined (N in step S53)
O), the process of step S54 is skipped, and the operating frequency clock down process ends.

As described above, when the operation mode of the portable information processing terminal 100 is the performance monitor mode M2, the operating frequency control system 101 can automatically switch the operating frequency in accordance with the usage status of the processor 1. it can.

[0102] For example, as shown in the timing chart of FIG. 11, between the timing t ₀ and time t ₇ of after the power supply 8 is turned on by the mobile information processing terminal 100,
It is assumed that a predetermined time T _mon exists. Further, at timings t ₁ , t ₂ ,..., T ₆ included between timing t ₀ and timing t ₇ , the switching of tasks executed by the processor 1 and the start of execution of interrupt processing
Assume that termination has occurred. For example, at the timing _{t 1,} the tasks that the processor 1 executes, is switched from a task TA _x to the task TA _y. Further, at the timing t _2, during the execution of the task TA _y, execution of the interrupt processing IP _b is started.

In this case, the timing detector 22 instructs the load detector 20 to execute the Total_ticks integration process for integrating the count value of the tick counter 10 at the timings t ₁ , t ₂ ,..., T ₆ . To instruct. The load amount detection unit 20 executes the Total_ticks integration process at each of the timings t ₁ , t ₂ ,..., T ₆ in response to the instruction from the timing detection unit 22.

[0104] After this, the timing detection unit 22, at the timing _{t 7,} the performance monitor timer 3
0 indicates that the time T _mon has elapsed. Therefore, the timing detection unit 22 instructs the frequency switching control unit 21 to execute an operation frequency automatic switching process for automatically switching the operation frequency according to the usage state of the processor 1. The frequency switching control unit 21 includes the timing detection unit 2
In response to an instruction from the 2, at the timing t _7, it executes the operating frequency automatic switching process. Thus, the operating frequency control system 101, when the operation mode of the portable information processing terminal 100 is in Performance Monitor mode M2, in accordance with the usage of the processor 1 in the period from the timing t ₀ to time t _7, the operating frequency Can be automatically switched.

For example, as shown in FIG.
_The timing t ₀ that arrives every time _mon elapses,
At t ₁₀ , t ₂₀ ,..., t ₉₀ , the usage state of the processor 1 is specified, and the operating frequency and the supply voltage can be appropriately switched.

Further, the operating frequency control system 101
When the operation mode of the portable information processing terminal 100 is the performance monitor mode M2, the operation frequency of the processor 1 is controlled in response to an instruction from a user program.

That is, the operating frequency control system 101
Changes the operating frequency of the processor 1 to a frequency in accordance with an instruction from the user program by executing the performance monitor forced setting process shown in the flowchart of FIG.

The performance monitor compulsory setting process shown in the flowchart of FIG. 13 will be described below.

When starting the performance monitor compulsory setting process in response to an instruction from the user program executed by the processor 1, the frequency switching control unit 21 determines whether the monitor flag 23 is "ON" (step S1). S
60).

The frequency switching control section 21 sets the monitor flag 2
If it is determined that 3 is "OFF" (NO in step S60), an error is notified to the user program (step S61), and the performance monitor forced setting process ends. That is, when the operation mode of the portable information processing terminal 100 is the fixed frequency operation mode M3, the frequency switching control unit 21 changes the operation frequency by executing the performance monitor forced setting process.
Not performed.

On the other hand, when the frequency switching control section 21 determines that the monitor flag 23 is "ON" (step S6).
(YES at 0), the measurement of the elapsed time by the performance monitor timer 30 is stopped (step S62).

The frequency switching control section 21 changes the operating frequency specified by the user program to the set frequency F
_It is specified as a _cpu (step S63).

The frequency switching control unit 21 sets the set frequency F
_It is determined whether or not _cpu is higher than the current operating frequency of the processor 1 (step S64).

The frequency switching control section 21 sets the set frequency F
_When it is determined that _cpu is higher than the current operating frequency (YES in step S64), the operating frequency clock-up process shown in the flowchart of FIG. 9 described above is executed (step S65), and the operating frequency of processor 1 is clocked up.

The frequency switching control section 21 sets the set frequency F
_If it is determined that _cpu is equal to or lower than the current operating frequency (NO in step S64), it is determined whether or not the set frequency F _cpu is lower than the current operating frequency in processor 1 (step S66).

The frequency switching control section 21 sets the set frequency F
_If it is determined that _cpu is smaller than the current operating frequency (YES in step S66), the operating frequency clock down process shown in the flowchart of FIG. 10 is executed (step S67), and the operating frequency of processor 1 is clocked down.

On the other hand, if frequency switching control section 21 determines that set frequency F _cpu is equal to the current operating frequency (NO in step S66), it skips the processing in step S67.

After that, the frequency switching control unit 21
Initialize with Total_ticks set to zero (step S6)
8).

Further, the frequency switching control unit 21 sets the variable Tick
Similarly, the _Reg and the variable Tick_Reg_OLD are initialized to zero (step S69).

The frequency switching control section 21 resets the performance monitor timer 30, starts (restarts) the measurement of the elapsed time again (step S70), and ends the performance monitor forced setting process.

Further, the operating frequency control system 101
When the operation mode of the portable information processing terminal 100 is the fixed frequency operation mode M3, usually, the operation frequency of the processor 1 is defined as the lowest frequency. At this time, the operating frequency control system 101 clocks up the operating frequency of the processor 1 in response to an instruction from a user program being executed by the processor 1.

That is, the operating frequency control system 101
Changes the operating frequency of the processor 1 to the frequency according to the instruction from the user program by the frequency switching control unit 21 executing the fixed frequency clock-up processing shown in the flowchart of FIG. Further, the operating frequency control system 101 restores (cancels) the operating frequency of the processor 1 which has been clocked up by executing the fixed frequency clock-up processing. Execute the frequency clock up release processing.

The fixed frequency clock-up processing shown in the flowchart of FIG. 14 will be described below.

When the fixed frequency clock up process is started in response to an instruction from the user program executed by the processor 1, the frequency switching control unit 21
3 is determined to be "ON" (step S8).
0).

The frequency switching control section 21 controls the monitor flag 2
If it is determined that No. 3 is "ON" (YES in step S80), an error is notified to the user program (step S81), and the fixed frequency clock-up processing ends. That is, when the operation mode of the portable information processing terminal 100 is the performance monitor mode M2, the frequency switching control unit 21 does not change the operating frequency by executing the fixed frequency clock-up process.

On the other hand, when the frequency switching control section 21 determines that the monitor flag 23 is “OFF” (step S
(NO at 80), the operating frequency specified by the user program is specified as the set frequency F _cpu (step S82).

The frequency switching control section 21 registers the operating frequency requested by the user program and its management number in the operating frequency request management table 12, and
It is stored in M3 (step S83). That is, the frequency switching control unit 21 attaches a management number for identifying the operating frequency for each request from the user program, and registers it in the data “management number” of the operating frequency request management table 12. Further, the frequency switching control unit 21 registers data indicating the operating frequency requested from the user program in the data “request frequency” of the operating frequency request management table 12 in association with the management number.

At this time, the frequency switching control section 21 notifies the user program of the management number registered in the operating frequency request management table 12 (step S84).

Thereafter, the frequency switching control section 21 determines whether or not the set frequency F _cpu is higher than the current operating frequency of the processor 1 (step S85).

The frequency switching control section 21 sets the set frequency F
_If it is determined that _cpu is higher than the current operating frequency (YES in step S85), the operating frequency clock-up process shown in the flowchart of FIG. 9 is executed to change the operating frequency of processor 1 (step S86),
The fixed frequency clock up processing ends.

On the other hand, when frequency switching control section 21 determines that set frequency F _cpu is equal to or lower than the current operating frequency (NO in step S85), it skips the processing in step S86 and executes the fixed frequency clock-up processing. finish.

Next, the fixed frequency clock-up release processing shown in the flowchart of FIG. 15 will be described.

When starting the fixed frequency clock-up release processing in response to an instruction from the user program executed by the processor 1, the frequency switching control section 21 determines whether or not the monitor flag 23 is "ON" ( Step S
90).

The frequency switching control section 21 sets the monitor flag 2
If it is determined that 3 is "ON" (YES in step S90), an error is notified to the user program (step S91), and the fixed frequency clock-up release processing ends. That is, when the operation mode of the portable information processing terminal 100 is the performance monitor mode M2, the operating frequency of the processor 1 is not changed by executing the above-described fixed frequency clock-up processing, and thus the operating frequency is restored. Not even.

On the other hand, when the frequency switching control section 21 determines that the monitor flag 23 is “OFF” (step S
NO at 90), and among the management numbers registered in the operating frequency request management table 12,
It is obtained from the user program (step S92).

The frequency switching control unit 21 deletes the management number acquired from the user program and the data indicating the operating frequency corresponding to the management number from the operating frequency request management table 12 (step S93).

The frequency switching control section 21 determines whether or not the management number and the operating frequency are registered in the operating frequency request management table 12 (step S94).

If frequency switching control section 21 determines that there is no registration in operating frequency request management table 12 (NO in step S94), it specifies the lowest frequency that can be set as the operating frequency of processor 1 as set frequency F _cpu. (Step S95).

On the other hand, when frequency switching control section 21 determines that there is a registration in operating frequency request management table 12 (YES in step S94), it searches operating frequency request management table 12 and determines from the data "request frequency". The highest operating frequency is detected and specified as the set frequency F _cpu (step S96).

Thereafter, the frequency switching control section 21 determines whether or not the set frequency F _cpu is lower than the current operating frequency in the processor 1 (step S97).

The frequency switching control unit 21 sets the set frequency F
_If it is determined that _cpu is smaller than the current operating frequency (YES in step S97), the operating frequency clock down process shown in the flowchart of FIG.
The operating frequency of the processor 1 is changed (Step S9)
8) The fixed frequency clock-up release processing ends.

On the other hand, when frequency switching control section 21 determines that set frequency F _cpu is _equal to or higher than the current operating frequency (NO in step S97), it skips the processing in step S98 and releases the fixed frequency clock-up release processing. To end.

As described above, when the operation mode of the portable information processing terminal 100 is the fixed frequency operation mode M3, the operating frequency control system 101 changes the operating frequency in accordance with an instruction from the user program executed by the processor 1. Can be switched.

As described above, according to the present invention,
When the operation mode of the portable information processing terminal 100 is the performance monitor mode M2, each time the predetermined time T _mon elapses, the load amount of the processor 1 is monitored to specify the usage state, and according to the specified usage state. The operating frequency can be automatically switched. Thereby, the operating frequency of the processor 1 can be appropriately switched according to the use situation.

When the operation mode of portable information processing terminal 100 is fixed frequency operation mode M3, the operation frequency can be switched in response to an instruction from a user program executed by processor 1. Thereby, the operating frequency of the processor 1 can be appropriately switched according to an instruction from the user program.

The present invention is not limited to the above embodiment, and various modifications and applications are possible. For example, the predetermined time T _{mo n} that the load becomes a period for monitoring the processor 1 may be set arbitrarily according to the instruction information input by the input unit 4.

Further, the ROM 2 may store a plurality of operating frequency data tables 11 having different settings, so that the type of operating mode for switching the operating frequency of the processor 1 can be selected from the plurality of modes. That is, the data “TICKma” constituting the operating frequency data table 11
A plurality of tables having different settings of “x” and data “TICKmin” may be prepared so that a table used when the operation mode of the portable information processing terminal 100 is the performance monitor mode M2 can be selected. In this case, by setting the tick value indicated by the data “TICKmax” to a small value, a mode in which the operating frequency of the processor 1 is easily clocked up and the clock is hardly reduced is set. In addition, by setting the tick value indicated by the data “TICKmax” to a large value, a mode is set in which the operating frequency of the processor 1 is hardly clocked up and clocked down.

In the above embodiment, the processor 1 has been described as having the tick counter 10.
It is not limited to this. That is, as shown in FIG. 16, for example, an RTC (Real Time Clock) 40 capable of counting a tick value is provided outside the processor 1 to monitor the load amount of the processor 1 and a predetermined time T _mon.
May be used for measurement.

[0149]

As described above, according to the present invention, the usage state of the processor can be specified each time a predetermined time elapses, and the operating frequency can be appropriately switched. Further, according to the present invention, the operating frequency of the processor can be appropriately switched according to an instruction from a user program executed by the processor.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of a portable information processing terminal to which an operating frequency control system according to an embodiment of the present invention is applied.

FIG. 2A is a diagram illustrating an operating frequency data table, and FIG. 2B is a diagram illustrating an operating frequency request management table.

FIG. 3 is a diagram showing a logical configuration of an operating frequency control system.

FIG. 4 is a diagram illustrating an operation mode of the portable information processing terminal.

FIG. 5 is a flowchart illustrating a performance monitor initialization process.

FIG. 6 is a flowchart illustrating a fixed frequency operation initialization process.

FIG. 7 is a flowchart illustrating a Total_ticks integration process.

FIG. 8 is a flowchart for explaining an operating frequency automatic switching process.

FIG. 9 is a flowchart illustrating an operation frequency clock-up process.

FIG. 10 is a flowchart for explaining an operating frequency clock down process.

FIG. 11 is a timing chart for explaining the operation of the operating frequency control system.

FIG. 12 is a timing chart for explaining the switching operation between the operating frequency and the supply voltage.

FIG. 13 is a flowchart illustrating a performance monitor forced setting process.

FIG. 14 is a flowchart illustrating fixed frequency clock-up processing.

FIG. 15 is a flowchart illustrating fixed frequency clock-up release processing.

FIG. 16 is a diagram showing a modification of the portable information processing terminal to which the operating frequency control system according to the embodiment of the present invention is applied.

FIG. 17 is a diagram for explaining a relationship between a processing speed and power consumption and an operating frequency.

FIG. 18 is a timing chart for explaining an operation of switching between an operating frequency and a supply voltage in a conventional operating frequency control system.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Processor 2 ROM 3 RAM 4 Input part 5 Display control part 6 Display part 7 Power supply control part 8 Power supply 10 Tick counter 11 Operating frequency data table 12 Operating frequency request management table 20 Load amount detection part 21 Frequency switching control part 22 Timing detection Unit 23 monitor flag 24 operation mode setting processing unit 30 performance monitor timer 40 RTC 100 portable information processing terminal 101 operation frequency control system M1 power off mode M2 performance monitor mode M3 fixed frequency operation mode

Claims (11)

[Claims] 1. An operating frequency control system for automatically switching an operating frequency of a processor, comprising: timing detecting means for detecting a first timing that arrives every time a predetermined time elapses; And a frequency control unit that, when the first timing is detected, specifies a use state of the processor and switches an operation frequency of the processor in accordance with the specified use state. 2. The apparatus according to claim 1, further comprising: a load amount detecting unit for detecting a load amount of the processor, wherein the timing detecting unit detects a second timing included within a predetermined time until the first timing arrives. Instruct the load amount detecting means to execute a process for detecting the load amount of the processor, and the frequency control means specifies the use state of the processor based on the processor load amount detected by the load amount detecting means. The operating frequency control system according to claim 1, wherein the operating frequency of the processor is switched. 3. The apparatus according to claim 2, wherein said timing detecting means detects, as the second timing, a switching timing of a task executed by the processor, and an execution start timing and an execution end timing of interrupt processing. 3. The operating frequency control system according to 2. 4. The load amount detecting means accumulates a tick value spent for processing executed by the processor,
The operating frequency control system according to claim 2, wherein a load amount of the processor is detected. 5. The operating frequency according to claim 1, wherein said frequency control means switches an operating frequency of the processor in accordance with an instruction from a user program executed by the processor. Control system. 6. A storage unit for storing data in which a load amount of a processor is associated with an operating frequency, wherein the frequency control unit refers to the data stored in the storage unit to store the load amount. Specifying an operating frequency corresponding to the amount of load on the processor detected by the detecting means,
The operating frequency control system according to any one of claims 2 to 5, wherein an operating frequency of the processor is switched. 7. A power supply for supplying a power supply voltage to a processor, and a power supply control unit for controlling a magnitude of a power supply voltage supplied from the power supply to the processor, wherein the storage unit stores a voltage supplied to the processor. Is stored together with data that associates a load amount and an operating frequency of the processor, and the frequency control unit refers to the data stored in the storage unit, and the load amount detection unit The magnitude of the supply voltage corresponding to the load amount of the processor detected by the power supply is specified, and the magnitude of the power supply voltage supplied from the power supply to the processor is controlled by the power supply control means to the magnitude of the specified supply voltage. The operating frequency control system according to claim 6, wherein: 8. An operating frequency control system for automatically switching an operating frequency of a processor, wherein the load amount of the processor is monitored at a predetermined timing, and the monitored load amount is monitored every time a predetermined time elapses. An operating frequency control system comprising: specifying a use state of a processor based on the operating condition; and switching an operating frequency of the processor according to the specified use state. 9. The operating frequency control system according to claim 8, wherein the operating frequency of the processor is switched according to an instruction from a user program executed by the processor. 10. An operating frequency control method for automatically switching an operating frequency of a processor, comprising: monitoring a load amount of a processor at a predetermined timing; and monitoring the load amount each time a predetermined time elapses. Operating frequency of the processor is specified based on the usage status, and the operating frequency of the processor is switched according to the specified usage status. 11. The operating frequency control method according to claim 10, wherein the operating frequency of the processor is switched according to an instruction from a user program executed by the processor.