JP2006025347A - Mobile terminal - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a mobile terminal which is capable of controlling feeding for saving power and of speedily starting executing processing relating to a specific function. <P>SOLUTION: When operation of an execution start key of a specific function is received, a main CPU 110 performs control to start supplying power to a RAM 142 during a period when no power is supplied to the RAM 142, transfers a program for the specific function from a flash memory 141 to the RAM 142, then causes a sub CPU 115 to run the program for the specific function in the RAM 142. When operation of an execution stop key of the specific function is received, the time is counted by a timer 150, and control is performed to stop supplying power to the RAM 142 after the lapse of predetermined time. Furthermore, when operation of the execution start key of the specific function is received, the main CPU 110 immediately causes the sub CPU 115 to run the program for the specific function in the RAM 142 during a period when power is supplied to the RAM 142. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a mobile terminal such as a mobile phone, and more particularly to power control in a multi-function mobile terminal including a plurality of CPUs.

  In recent years, mobile terminals having multiple functions such as mobile phones with camera functions have become widespread, and multiple functions can be achieved by installing multiple CPUs (Central Processing Units) in order to improve the performance of additional functions. Mobile terminals that can be shared and realized are being researched and developed. Note that portable terminals that use different CPUs for baseband processing for communication and for other application processing have been developed, but there are various ways of sharing the functions of a plurality of CPUs.

  For example, in the case of a mobile phone with a high-resolution camera function having a plurality of CPUs, the CPU on the master side (hereinafter referred to as “main CPU”) performs user communication detection, telephone communication control including telephone standby control, and the like. It is conceivable that image processing related to a high-resolution camera function is performed at high speed by a CPU on the slave side (hereinafter referred to as “sub CPU”) while being controlled by the main CPU.

In order to improve the execution performance of the processing related to the additional function of the mobile phone such as the camera function of this example, in order to avoid the conflict of memory access, the sub CPU is a memory that the main CPU mainly reads and writes. It is desirable to read and write to a separate dedicated memory, and to realize processing related to the additional function by executing a program in the dedicated memory.
However, if a non-volatile dedicated memory for storing the program executed by the sub CPU is provided separately from the non-volatile memory for storing the program executed by the main CPU in advance, all the programs are stored in one non-volatile memory. Compared to the case where data are stored in a centralized manner, the hardware mechanism for program update accompanying version upgrade or the like tends to be complicated. In addition, as the dedicated memory on the sub CPU side, a volatile memory such as DRAM (Dynamic Random Access Memory) which tends to have relatively high performance in both reading and writing is desirable. In addition to this, a nonvolatile memory is used as the dedicated memory. It is not so preferable to provide a space for the purpose of saving space.

Therefore, the following method can be considered as a method for executing processing related to the additional function at high speed without any problem.
The dedicated memory of the sub CPU of the cellular phone is limited to the volatile memory, and the upgraded program is stored in the nonvolatile memory on the main CPU side through a conventional interface for setting data from the outside to the nonvolatile memory of the main CPU. Once stored, the main CPU temporarily accesses the dedicated memory of the sub CPU and copies the program, that is, a method of reading the program from the nonvolatile memory and recording it in the dedicated memory (hereinafter referred to as “program”). "Transfer method").

  By the way, mobile terminals such as mobile phones are required to reduce power consumption so that they can be driven for a long time with a built-in battery, and development of technology for reducing power consumption is continued. ing. In addition, as a technique for suppressing this power consumption, for example, a technique of dividing the apparatus into a plurality of functional blocks and supplying power only to necessary functional blocks (see Patent Document 1), a shared memory accessed from a plurality of CPUs, or the like. A technique for switching the power consumption of each bank (see Patent Document 2) is known.

Therefore, in order to suppress power consumption in a portable terminal having a plurality of CPUs, when it is not necessary to execute a sub CPU responsible for an additional function such as a camera function, a method of stopping power supply to a dedicated memory of the sub CPU (hereinafter, referred to as “sub CPU”). “Power supply control method”) can be assumed.
JP-A-7-212736 JP 2004-38642 A

  However, when considering a portable terminal that employs such a power supply control method in combination with the above-described program transfer method, when a process related to an additional function performed by the sub CPU is required, a program for performing the process is a non-volatile memory. Since the sub CPU can gradually start executing the program after the data is read from and recorded in the volatile memory that is the dedicated memory of the sub CPU, the execution of the processing related to the additional function is delayed. Therefore, the user of the mobile terminal has to wait for a while after performing an operation requesting the execution of the additional function until the processing related to the function is started.

  Therefore, the present invention has been made in view of such problems, and is a portable terminal including a sub CPU that is responsible for executing a process related to a specific function, and controls power supply to at least a volatile memory in order to reduce power consumption to some extent. An object of the present invention is to provide a portable terminal that can perform a process related to a specific function requested by a user and can quickly start the process.

  In order to solve the above problems, a mobile terminal according to the present invention includes a volatile memory, a program execution unit connected to the volatile memory, a storage unit storing a program for executing a specific function, and a specific Detecting means for detecting a user operation that requests execution of a function; and when power is not supplied to the volatile memory, when a user operation that requests execution of a specific function is detected, power of the volatile memory is detected. Power supply control means for starting supply and stopping power supply to the volatile memory after a predetermined time has elapsed from when a predetermined condition relating to completion of execution of the specific function is satisfied; and the volatile property by the power supply control means A recording unit that reads a program for executing a specific function from the storage unit and records it in the volatile memory at the start of power supply to the memory; and When the recording is completed, and when a user operation requesting execution of the specific function is detected when power is supplied to the volatile memory, the program execution unit executes the program for executing the specific function. Execution control means for starting the process.

  With the above-described configuration, the mobile terminal according to the present invention can be used for a predetermined time from when a predetermined condition related to the end of execution of the specific function is satisfied, for example, when an operation indicating a request to stop execution of the specific function is performed by the user Since the power supply to the volatile memory is stopped after the elapse of time, the power consumption of the mobile terminal is reduced after the elapse of the predetermined time, and the user requests an operation for executing the specific function before the elapse of the predetermined time. When the operation is performed, the specific function execution program is not recorded in the volatile memory, that is, transferred, and the execution of the specific function execution program is started immediately, so that the user benefits from a quick response. Will be able to.

  In addition, when the factor that requested the user to execute the specific function does not change so much in a short time, the user may request the execution of the specific function continuously several times with a certain time interval. Is somewhat high. For example, if the specific function is a camera function that performs image processing every time a camera is photographed, if the user is in a sightseeing spot where there are many things to be photographed, the user will stop and request the execution of the specific function. It can be said that the possibility of repeating the instruction multiple times is high to some extent. Therefore, if the predetermined time is appropriately set in view of the relationship with the specific function, it is possible to achieve a balanced balance between reducing the power consumption of the mobile terminal and improving the response at the start of execution of the specific function. For example, if the specific function is a camera function and the predetermined time is assumed to be 5 minutes, the user starts to execute the camera function when shooting a plurality of times at intervals of less than 5 minutes. The response from the request is quick, and the user can be prevented from missing the shooting opportunity. In addition, the user does not shoot again for more than 5 minutes after the user finishes shooting. In such a case, the power supply to the volatile memory is stopped and the power consumption of the portable terminal is suppressed.

  Here, the portable terminal includes a first CPU and a second CPU, the storage means is a nonvolatile memory connected to the first CPU, further stores a program for the first CPU, and the volatile The memory is also connected to the first CPU, and some of the functions of the detection means, the power supply control means, the recording means, and the execution control means are realized through execution of the first CPU program by the first CPU. The first CPU accesses the volatile memory only during the recording in order to realize the recording function related to the recording means, and the program execution means is connected to the first CPU. It may be the second CPU.

  Thereby, since the program for the first CPU and the program for the second CPU are stored in the nonvolatile memory that retains the stored contents even when the power supply is cut off, the portable terminal is used when it is not necessary to execute all the functions of the portable terminal. The entire power supply may be turned off. After the power supply is turned on, the first CPU can execute a program in the nonvolatile memory, and the second CPU volatilizes from the nonvolatile memory by the first CPU. The specific function execution program transferred to the volatile memory can be executed. Since the first CPU accesses the volatile memory only during the transfer, the volatile memory is accessed with the first CPU while the second CPU is executing the specific function execution program. Since no competition occurs, the second CPU can execute the specific function execution program at high speed.

The power supply control means further starts supplying power to the second CPU when a user operation requesting execution of the specific function is detected, and supplies power to the second CPU when the predetermined condition is satisfied. It is good also as stopping.
Thereby, since power supply control is performed for the second CPU that bears the specific function, it is possible to further reduce the power consumption of the portable terminal when it is not necessary to execute the specific function. In addition, since the power supply stop to the second CPU is performed for a predetermined time earlier than the power supply stop to the volatile memory, the power supply stop time to the second CPU is simply matched with the power supply stop time to the volatile memory. Compared with the case, the power consumption can be further reduced.

Further, the detection means further detects a user operation requesting the execution stop of the specific function and a user operation related to the execution of the specific function, and the predetermined condition is that the user operation requesting the stop of the execution of the specific function is performed. It may be that the specific time has elapsed since the last detection of the user operation related to the execution of the specific function.
The last time detected here means that when the next user operation is performed within a specific time from a certain user operation, the next user operation is detected. If the next user operation is performed within a specific time, it means that the next user operation is detected.

  As a result, the power supply to the second CPU is stopped when the user performs an operation requesting to stop the execution of the specific function and when the specific time has elapsed since the user stopped performing the operation related to the specific function. Power consumption is reduced. That is, even when the user no longer needs to execute the specific function, the power consumption is suppressed even when the user forgets to perform an operation for requesting the execution stop of the specific function.

Further, the power supply control means further performs control for switching between supply and stop of power supply to the second CPU based on a specific standard related to execution and stop of the specific function, and the predetermined condition is the power supply The supply of power to the second CPU may be stopped by the control means.
As a result, when the execution of the specific function is unnecessary, the power supply to the second CPU can be stopped to suppress the power consumption of the portable terminal, and the power supply to the volatile memory is continued for a predetermined time thereafter. When the execution of the specific function is required again within the predetermined time, the specific function can be quickly executed without transferring the specific function execution program.

  The mobile terminal is a mobile phone with a built-in battery, and the first CPU further performs communication control including control for waiting for telephone reception by executing a part of the first CPU program, The specific function is a function related to video or audio, the specific function execution program is a program for processing data related to video or audio, and the power supply control means includes the battery to the volatile memory. The power supply path to the volatile memory may be stopped by cutting off the power transmission path, and the supply of power to the volatile memory may be started by stopping the power transmission path from being cut off.

As a result, the mobile phone that is a mobile terminal can realize a data processing function related to video or audio at high speed by the second CPU, and can make the built-in battery relatively long lasting.
The portable terminal may further include a reception recording unit that receives a program from the outside of the portable terminal and records the program in the nonvolatile memory.

As a result, when the specific function execution program is upgraded, the program can be acquired and used from the outside.
The detection unit may further detect a user operation requesting to stop execution of the specific function, and the predetermined condition may be that a user operation requesting to stop execution of the specific function is detected.

  As a result, when the user performs an operation requesting to stop the execution of the specific function, the power supply to the volatile memory is continued for a predetermined time thereafter, and the power supply is stopped after the predetermined time has elapsed. Does not need to instruct itself to stop the power supply to the volatile memory after a predetermined time, simply by performing an operation to request the execution of the specific function when it is no longer necessary. The user can benefit from the power saving control, and the user can obtain a quick response when performing an operation related to the execution request for the specific function again within a predetermined time.

The detection unit may further detect a user operation related to the execution of the specific function, and the predetermined condition may be when a user operation related to the execution of the specific function is last detected.
The last detected time here means that when the next user operation is performed within a predetermined time from a certain user operation, the next user operation is detected. If the next user operation is performed within a predetermined time, it means the time when the next user operation is detected.

Thereby, even if the user does not particularly perform an operation for requesting the execution stop of the specific function, the power consumption is suppressed only by not performing the operation regarding the specific function.
Further, the mobile terminal is a mobile phone incorporating a battery, and the power supply control means stops power supply to the volatile memory by cutting off a power transmission path from the battery to the volatile memory. Then, the supply of power to the volatile memory may be started by stopping the interruption of the power transmission path.

Thereby, the mobile phone which is a mobile terminal can be made to have a relatively long battery.
The control program according to the present invention is a control for causing a main CPU in a portable terminal having a storage unit storing a program for executing a specific function, a volatile memory, a main CPU, and a sub CPU to execute power control processing. The power control process includes: a detection step for detecting a user operation requesting execution of a specific function; and a user operation requesting execution of the specific function when power is not supplied to the volatile memory. Power supply control that starts supplying power to the volatile memory when detected, and stops supplying power to the volatile memory after a predetermined time has elapsed since a predetermined condition related to completion of execution of a specific function is satisfied And when the power supply control step starts power supply to the volatile memory, A recording step of reading from the storage means and recording in the volatile memory; a user who requests execution of a specific function when the recording by the recording step is completed and when power is supplied to the volatile memory And an execution control step for causing the sub CPU to start execution of the specific function execution program when an operation is detected.

  When this control program is stored in the memory of the mobile terminal and executed by the main CPU, the mobile terminal becomes volatile after a predetermined time elapses from when a predetermined condition for completion of execution of the specific function is satisfied. Since the power supply to the memory is stopped, the power consumption of the mobile terminal becomes small after the predetermined time has elapsed, and when the user performs an operation requesting the execution of the specific function before the predetermined time has elapsed. At the time of the operation, the specific function execution program is not recorded or transferred to the volatile memory, but the specific function execution program is immediately started to be executed by the sub CPU, so that the user can benefit from quick response. become able to.

Hereinafter, a mobile phone according to an embodiment of the present invention will be described.
<Configuration>
FIG. 1 is a configuration diagram of a mobile phone according to an embodiment of the present invention.
As shown in the figure, the mobile phone 100 includes a main CPU 110, a sub CPU 115, a battery 130, a SW (Switch) 131, a RAM (Random Access Memory) 140, a flash memory 141, a RAM 142, a SW 145, a timer 150, a key group 161, An LCD (Liquid Crystal Display) 162, a communication unit 171, a camera unit 172, and a data input I / F (Interface) 173 are provided.

  Here, the main CPU 110, in addition to executing telephone communication control including telephone standby control, is responsible for accepting input operations by the user and realizing general functions of the mobile phone in accordance with the input operations. CPU to control. The main CPU normally accesses the RAM 140 and the flash memory 141, and accesses the RAM 142 only temporarily.

  The sub CPU 115 is a CPU responsible for realizing an image data processing function such as encoding and compression of a signal sent from the camera unit 172, and accesses only the RAM 142. Note that the sub CPU 115 and the main CPU 110 are connected by a signal line and can exchange data with each other, and a control signal such as a reset signal can be given from the main CPU 110 to the sub CPU 115.

The battery 130 is a battery that supplies power to each unit in the mobile phone 100. For the sake of convenience, FIG. 1 only shows that the battery 130 is connected to the sub CPU 115 and the RAM 142 via the SW 131, but the battery 130 is also connected to other units such as the CPU 110, the RAM 140, and the camera unit 172. ing.
The RAM 140 is a 16-megabyte volatile memory used by the main CPU 110 for reading and writing data, and the flash memory 141 is a 32-megabyte non-volatile memory storing a program to be read and executed by the main CPU. is there. The RAM 142 stores a program to be read and executed by the sub CPU 115, and is a 16 megabyte volatile DRAM used by the sub CPU 115 to read and write data. The SW 145 is a switch controlled by the main CPU 110 so that the main CPU 110 can access the RAM 142 only when the main CPU 110 needs to write a program to the RAM 142.

The timer 150 has a function of measuring the passage of time under the control of the main CPU 110.
The key group 161 is a numeric keypad and other keys arranged on the surface of the casing of the mobile phone 100, and includes a start key and a stop key for the camera function, and various keys for accepting various user operations related to the camera function. .

The LCD 162 has a function of displaying an image generated as a result of the processing executed by the main CPU 110 in response to a user operation, and displaying an image captured by the camera transmitted from the sub CPU 115.
The communication unit 171 is connected to an antenna and includes a signal processing circuit, a modulation / demodulation circuit, a baseband processing circuit, and the like for performing wireless communication in accordance with a predetermined mobile phone communication protocol under the control of the main CPU 110.

The camera unit 172 includes a lens and a charge coupled device (CCD), and has a function of transmitting an image signal obtained by imaging to the sub CPU 115.
The data input I / F 173 is an interface for taking in data such as upgraded programs into the mobile phone 100 from the outside.
<Data>
FIG. 2 is a diagram showing a program stored in the flash memory 141.

As shown in the figure, a control program 201 and a camera processing program 202 are stored in advance in the flash memory 141, and the camera processing program 202 is stored in the RAM 142 when power is supplied to the RAM 142. Copyed by the CPU 110.
The control program 201 includes a telephone communication control program for performing telephone communication including telephone standby control, a power control program for performing power supply control to the RAM 142 and the sub CPU 115, and the like. 141 is a program that is read from 141 and executed.

The camera processing program 202 is a program for performing image data processing such as encoding and compression of a signal sent from the camera unit 172, generating image data, and displaying the image data on the LCD 162. It is a program that is read from and executed.
<Operation>
Hereinafter, the operation of the mobile phone 100 having the above-described configuration will be described.

FIG. 3 is a flowchart showing a basic control operation by the main CPU 110 of the mobile phone 100.
The main CPU 110 basically performs the processing shown in FIG. 3 by reading and executing the control program 201 stored in the flash memory 141. Note that the CPU 110 executes, in a pseudo-parallel manner, processing steps S11 similar to those in a conventional mobile phone having no camera function and processing steps S21 to S33 associated with the execution of the camera function by so-called multitask control or the like. Shall.

  First, when the main CPU 110 detects an operation of a camera function start key by the user (step S21), the main CPU 110 controls the SW 131 so that the power from the battery 130 is supplied to the RAM 142 on the sub CPU 115 side (step S22). ). Before the start of the control operation shown in FIG. 3, the SW 131 blocks the power supply path from the battery 130 to the sub CPU 115 and the power supply path from the battery 130 to the RAM 142.

  After the power supply to the RAM 142 is started, the main CPU 110 controls the SW 145 to enable access to the RAM 142, reads the camera processing program 202 in the flash memory 141, writes the camera processing program 202 in the RAM 142, and then switches to the SW 145. And the data transmission path connecting the main CPU 110 and the RAM 142 is blocked (step S23).

  After storing the camera processing program 202 in the RAM 142, the main CPU 110 gives a reset signal to the sub CPU 115 and controls the SW 131 so that the power from the battery 130 is supplied to the sub CPU 115. The sub CPU 115 is activated by releasing the reset signal after waiting for milliseconds or the like to stabilize the power supply, and the execution of the camera processing program is started (step S24). The sub CPU 115 is set in advance to read and execute a program from a predetermined address in the RAM 142 when the sub CPU 115 is activated. The main CPU 110 records the camera processing program at the predetermined address in the RAM 142 and then executes the sub CPU 115. By starting the CPU 115, the sub CPU 115 can start executing the camera processing program.

  After starting the sub CPU 115, the main CPU 110 makes settings for causing the timer 150 to measure the elapse of the predetermined time Ta, and starts the timer 150 to measure time (step S25). The predetermined time Ta is, for example, 1 minute. Thereafter, a notification that the predetermined time Ta has elapsed is received from the timer 150 (step S26), or when the operation of the stop key of the camera function by the user is detected (step S27), the main CPU 110 controls the SW 131. Then, the power supply path from the battery 130 to the sub CPU 115 is interrupted to stop the power supply to the sub CPU 115 (step S29).

  Further, after the start of the time measurement in step S25 and before the predetermined time Ta has elapsed (step S26), the user does not operate the stop key of the camera function (step S27), and the user relates to the camera function. When it is detected that various keys have been operated (step S28), the main CPU 110 notifies the sub CPU 115 of the operation of the various keys, and causes the timer 150 to measure the elapse of the predetermined time Ta. The data is set again, and the timer 150 starts counting again from the beginning (step S25). When the sub CPU 115 is notified of the operation of various keys, the sub CPU 115 performs necessary processing according to the operation. For example, when a zoom-in key operation is notified, the image data captured and generated by the camera is enlarged and displayed on the LCD 162.

Accordingly, in steps S25 to S28, when the predetermined time Ta has elapsed from when the camera function start key or various keys related to the camera function are last operated, or when the camera function stop key is operated, the process proceeds to the sub CPU 115. The power supply is stopped.
After the power supply to the sub CPU 115 is stopped, the main CPU 110 performs setting for causing the timer 150 to measure the elapse of the predetermined time Tb, and starts the timer 150 to measure time (step S30). The predetermined time Tb is, for example, 5 minutes. After that, when the notification that the predetermined time Tb has elapsed is received from the timer 150 (step S31), the main CPU 110 controls the SW 131 to shut off the power supply path from the battery 130 to the RAM 142, thereby supplying the RAM 142 to the RAM 142. The power supply is stopped (step S33), and the power supply to the RAM 142 is stopped until the user again operates the camera function start key (step S21).

  If the user operates the start key of the camera function (step S32) after the start of time measurement in step S30 and before the predetermined time Tb has elapsed (step S31), the RAM 142 has already been stored in the RAM 142. Since the power remains supplied, the main CPU 110 controls the SW 131 so as to start supplying power to the sub CPU 115 without transferring the camera processing program to the RAM 142 again. Execution is started (step S24).

In addition to the processing described above, the main CPU 110 takes in the upgraded control program and camera processing program from the outside via the data input I / F 173 in response to a specific key operation by the user, and stores it in the flash memory 141. Execute the recording process.
Hereinafter, power supply control to the sub CPU 115 and the RAM 142 executed by the main CPU 110 in the mobile phone 100 will be described based on a specific example.

FIG. 4 is a time chart showing power supply control for the RAM and the sub CPU on the sub CPU side. In the figure, a period during which power is supplied is represented by a solid line labeled ON.
Here, time t1 and time t4 in the figure indicate the time when the user operated the camera function start key, and time t3 and time t5 indicate the time when the user operated the camera function stop key. This will be explained as a premise.

First, after the power key of the mobile phone 100 is operated by the user and the main CPU of the mobile phone 100 is started, until the start key operation indicating the camera function execution request is performed by the user at time t1. The sub CPU 115 and the RAM 142 are not supplied with power.
The main CPU 110 detects that the user has operated the camera function start key at time t1 (step S21), starts supplying power to the RAM 142 (step S22), and transfers the camera processing program to the RAM 142 (step S21). S23), power supply to the sub CPU 115 is started at the time t2 when the transfer is completed, and the camera processing program is executed by the sub CPU 115 (step S24). Thereafter, the user operates various keys related to the camera function, and the captured image is displayed on the LCD 162 by the function of the sub CPU 115 in response to the operation.

  Thereafter, the user operates the stop key to end the execution of the camera function. The main CPU 110 detects that the user has operated the camera function stop key at time t3 (step S27), stops the power supply to the sub CPU 115 (step S29), and starts the timer 150 (step S30). . When the user again operates the start key to request execution of the camera function before the elapse of the predetermined time Tb is measured by the timer 150, the main CPU 110 causes the camera function start key to be displayed to the user at time t4. The operation is detected (step S32), the power supply to the sub CPU 115 is started, and the camera processing program is executed by the sub CPU 115 (step S24). At this time, since step S23 is not executed after the start key operation time t4 by the user, the camera processing program is executed by the sub CPU 115 almost without delay from the time t4, and the response to the user operation is improved.

  Thereafter, when the user wants to end the execution of the camera function, the user operates the stop key. The main CPU 110 detects that the user has operated the camera function stop key at time t5 (step S27), stops the power supply to the sub CPU 115 (step S29), and starts the timer 150 (step S30). . If the user does not operate the start key of the camera function before the timer 150 measures the elapse of the predetermined time Tb, at time t6 when the predetermined time Tb elapses (step S31), the process returns to the RAM 142. Is stopped (step S33).

As described above, according to the mobile phone 100, if the predetermined time Tb is 5 minutes, the user requested the camera function to be executed 5 minutes after the operation related to the camera function execution stop instruction. In this case, it is possible to benefit from a quick response as compared with a case where execution of the camera function is requested for more than 5 minutes.
Such a mobile phone 100 meets the needs for practically demanding a good response after operating the start key of the camera function so as not to miss a photo opportunity. In a situation where a user shoots, for example, when shooting at a sightseeing spot, in general, not only shooting once but also a tendency to shoot continuously several times, although there is a certain time interval. As long as the predetermined time Tb is set appropriately, such a mobile phone 100 realizes a good balance between extending the built-in battery 130 and improving the response of the camera function. It will be a thing.
<Supplement>
The mobile phone as an embodiment of the mobile terminal according to the present invention has been described above. However, the mobile phone can be modified as follows, and the present invention is not limited to the mobile phone 100 shown in the above-described embodiment. Of course.
(1) The present invention can be applied to any mobile terminal such as a so-called mobile PC other than the mobile phone shown in the present embodiment and having a built-in battery and a plurality of CPUs.
(2) In the present embodiment, the sub CPU 115 is responsible for the camera function. However, the present invention is not limited to this, and the sub CPU 115 may assume any function. The main CPU 110 stores a program for realizing the function. Any configuration may be used as long as it is transferred from the nonvolatile memory to the RAM 142. As a function of the sub CPU 115, for example, functions that require relatively high-speed processing such as encoding and playback of moving images and sounds in addition to still images are conceivable. When the CPU 115 takes charge, the effectiveness of providing the RAM 142 for the sub CPU 115 is exhibited.

Further, the sub CPU 115 assumes a plurality of functions, and in response to an execution request for each function, the main CPU 110 selects a function execution program corresponding to the requested function and reads it from the flash memory 141. Only the selected function execution program may be written in the RAM 142 and the sub CPU 115 may execute the selected function execution program. In such a case, the capacity of the RAM 142 may be smaller than the total capacity of the function execution programs corresponding to each of a plurality of functions performed by the sub CPU 115. Further, the values of the predetermined time Ta and the predetermined time Tb shown in the present embodiment may be determined for each function, and the respective values may be applied according to the selected function.
(3) The values of the predetermined time Ta and the predetermined time Tb shown in the present embodiment may be changed in relation to the remaining battery level. That is, the predetermined time Ta and the predetermined time Tb may be shortened as the remaining amount of the battery decreases.
(4) In the present embodiment, the RAM 142 is a DRAM, but any volatile memory may be used. The flash memory 141 may be anything as long as it is a non-volatile memory that retains stored contents even when power supply is cut off, but a writable type is preferable in consideration of version upgrade of a built-in program.

  Further, a program is recorded in advance on a recording medium such as a hard disk instead of the flash memory 141, and when the power supply to the RAM 142 is started, the main CPU 110 reads a camera processing program from the recording medium instead of the flash memory 141 and stores it in the RAM 142. It may be written. In this case, the control program for the main CPU 110 is also recorded in the recording medium, and the main CPU 110 has a function of reading the control program from the recording medium and writing it in the RAM 140 and executing the control program. It may be.

Note that the capacity of each memory shown in the present embodiment is not particularly limited to 16 megabytes or 32 megabytes.
(5) In this embodiment, the main CPU 110 is temporarily connected to the RAM 142 only when the camera processing program is transferred by controlling the SW 145. However, the main CPU 110 does not provide the special SW 145 and the camera processing is performed by the main CPU 110. The RAM 142 may be temporarily accessed only when the program is transferred. The RAM 142 and the sub CPU 115 may be formed in one semiconductor chip, and the main CPU 110 may access the RAM 142 through the interface of the semiconductor chip.
(6) In the present embodiment, the main CPU 110 performs power supply control on each of the RAM 142 and the sub CPU 115 in conjunction with the user operation related to the camera function, but in a form linked to the user operation related to the camera function. For example, an embodiment in which no power supply control is performed on the sub CPU 115 may be considered. However, from the viewpoint of power consumption suppression, power supply control to both sides as shown in this embodiment is preferable.

  In the case where the main CPU 110 performs power supply control to the sub CPU 115 based on a specific standard related to execution and stop of a specific function such as a camera function, a predetermined time after the power supply to the sub CPU 115 is stopped. The power supply to the RAM 142 may be stopped. As a result, when the power supply to the sub CPU 115 is attempted to be resumed within a predetermined time after the power supply to the sub CPU 115 is stopped, the power supply to the RAM 142 is still continued. As soon as power is supplied, the program in the RAM 142 can be executed.

  The mobile terminal according to the present invention can be used for a multi-function mobile phone, a wireless communication terminal, or the like that incorporates a battery and has a plurality of CPUs.

1 is a configuration diagram of a mobile phone according to an embodiment of the present invention. It is a figure which shows the program memorize | stored in flash memory. It is a flowchart which shows the basic control operation by main CPU of a mobile telephone. It is a time chart which shows electric power supply control with respect to RAM and sub CPU by the side of a sub CPU.

Explanation of symbols

100 mobile phone 110 main CPU
115 Sub CPU
130 Battery 131, 145 SW (Switch)
140, 142 RAM (Random Access Memory)
141 Flash memory 150 Timer 161 Key group 162 LCD (Liquid Crystal Display)
171 Communication unit 171
172 Camera unit 173 Data input I / F (Interface)

Claims (11)

Volatile memory,
Program execution means connected to the volatile memory;
Storage means for storing a program for executing a specific function;
Detection means for detecting a user operation requesting execution of a specific function;
When a user operation requesting execution of a specific function is detected when power is not supplied to the volatile memory, supply of power to the volatile memory is started, and a predetermined condition related to the end of execution of the specific function is Power supply control means for stopping power supply to the volatile memory after elapse of a predetermined time from when satisfied,
Recording means for reading a specific function execution program from the storage means and recording it in the volatile memory at the start of power supply to the volatile memory by the power supply control means;
When the recording by the recording unit is completed, and when a user operation requesting execution of the specific function is detected when power is supplied to the volatile memory, the program execution unit executes the specific function. A mobile terminal comprising: an execution control means for starting execution of the program for use. The portable terminal includes a first CPU and a second CPU,
The storage means is a non-volatile memory connected to the first CPU, and further stores a program for the first CPU,
The volatile memory is also connected to the first CPU,
A part of each function of the detection means, the power supply control means, the recording means, and the execution control means is realized through execution by the first CPU of the first CPU program,
The first CPU accesses the volatile memory only during the recording in order to realize the recording function related to the recording means,
The mobile terminal according to claim 1, wherein the program execution unit is a second CPU connected to the first CPU. The power supply control means further starts power supply to the second CPU when a user operation requesting execution of a specific function is detected, and stops power supply to the second CPU when the predetermined condition is satisfied. The mobile terminal according to claim 2, wherein: The detection means further detects a user operation requesting to stop execution of the specific function and a user operation related to execution of the specific function,
The predetermined condition is that a user operation requesting to stop execution of a specific function is detected, or that a specific time has elapsed since the user operation related to execution of the specific function was last detected. The mobile terminal according to claim 3. The power supply control means further performs control to switch between supply of power to the second CPU and stop of supply based on a specific standard related to execution and stop of the specific function,
The portable terminal according to claim 2, wherein the predetermined condition is that the power supply control unit stops the supply of power to the second CPU. The mobile terminal is a mobile phone incorporating a battery,
The first CPU further performs communication control including control for waiting for telephone reception by executing a part of the first CPU program,
The specific function is a function related to video or audio,
The specific function execution program is a program for processing data relating to video or audio,
The power supply control means stops power supply to the volatile memory by cutting off a power transmission path from the battery to the volatile memory, and stops cutting off the power transmission path to stop the power transmission path. The mobile terminal according to any one of claims 2 to 5, wherein power supply to the mobile phone is started. The portable terminal according to claim 6, further comprising a reception recording unit that receives a program from outside the portable terminal and records the program in the nonvolatile memory. The detection means further detects a user operation requesting to stop execution of the specific function,
The mobile terminal according to claim 1, wherein the predetermined condition is that a user operation requesting to stop execution of a specific function is detected. The detection means further detects a user operation related to execution of the specific function,
The mobile terminal according to claim 1, wherein the predetermined condition is when a user operation related to execution of a specific function is last detected. The mobile terminal is a mobile phone incorporating a battery,
The power supply control means stops power supply to the volatile memory by cutting off a power transmission path from the battery to the volatile memory, and stops cutting off the power transmission path to stop the power transmission path. The mobile terminal according to claim 8 or 9, wherein power supply to the mobile phone is started. A control program for causing a main CPU in a portable terminal including a storage unit storing a specific function execution program, a volatile memory, a main CPU, and a sub CPU to execute power control processing,
The power control process includes:
A detection step for detecting a user operation requesting execution of a specific function;
When a user operation requesting execution of a specific function is detected when power is not supplied to the volatile memory, supply of power to the volatile memory is started, and a predetermined condition relating to the end of execution of the specific function is A power supply control step of stopping the power supply to the volatile memory after a predetermined time has elapsed from when it is satisfied;
A recording step of reading a specific function execution program from the storage means and recording it in the volatile memory at the start of power supply to the volatile memory by the power supply control step;
When the recording by the recording step is completed, and when a user operation requesting execution of the specific function is detected when power is supplied to the volatile memory, the sub CPU performs the specific function execution. An execution control step for starting execution of the program.

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