JP2008107914A - Microcomputer, program and electronic control device for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress useless processing and power consumption of a microcomputer. <P>SOLUTION: The microcomputer enters a sleep mode when a plurality of application tasks are executed and all the application tasks are not needed to be executed. When the microcomputer in the sleep mode wakes up by one of plural kinds of wake-up factors, a state management task wakes up, and the current wake-up factor this time is discriminated by the state management task (S310), and only the application task to wake up by the discriminated wake-up factor, is worken up (S320). The unnecessary increase of processing load is thereby prevented, and the following problem can be solved that unnecessary application tasks cannot be executed, so that a sleepable task cannot be determined quickly. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a technique for reducing power consumption of a microcomputer.

  2. Description of the Related Art Conventionally, for example, in a microcomputer mounted on an electronic control device for a vehicle, a plurality of application tasks for controlling an object to be controlled are executed by using a multitask function by an OS (Operating System) Yes.

  In this type of microcomputer, when it is not necessary to perform processing, for example, the CPU clock frequency or power supply voltage is lowered, or the clock supply or power supply to the CPU is stopped, Transition to a sleep mode, which consumes less power than during normal operation, is performed (see, for example, Patent Document 1).

  Next, a specific example of a method for shifting the microcomputer to the sleep mode will be described with reference to FIG. Hereinafter, the application task is also referred to as an application task for short. In addition, in this specification, for the sake of convenience, an expression based on a program such as “task is ...” is appropriately used, but the expression is an operation of a functional unit realized by the computer executing the program. Indicates the contents (or simply, the function contents of the program).

  First, in the example of FIG. 7, there are an application task 1 and an application task 2 as application tasks, and a state management task for waking up each of these application tasks 1 and 2 and controlling sleep / wakeup, etc. is there. In this example, the state management task is woken up at regular intervals. In FIG. 7, times t1, t3, and t6 are wake-up timings of the state management task. The priority order of each task is in the order of “status management task> application task 1> application task 2.” The application tasks 1 and 2 are requested to wake up by the state management task that wakes up at time t1, and the execution of the application task 1 starts as soon as the execution of the state management task ends. Since the priority is lower than that of the state management task and the application task 1, the execution is started from the time t2 when the execution of the application task 1 is completed. Further, the application task 2 is interrupted during execution of the next state management task (time t3 to t4), and the execution period extends to time t5 between time t3 and time t6.

  Here, each of the application tasks 1 and 2 determines whether or not the own task does not have to be executed (hereinafter referred to as a sleep-enabled state). Of the sleep propriety flags provided for each task, a process for setting a sleep feasibility flag corresponding to the own task is performed.

  When the state management task wakes up, it checks the sleep enable / disable flags of all the application tasks. If all of them are set, the state management task is used to shift the microcomputer to the sleep mode without making a wakeup request for the application task. Process.

  Therefore, in the example of FIG. 7, when it is determined that the application task 1 is in the sleep-capable state at time t2, and it is determined that the application task 2 is in the sleep-capable state at time t5, the state management task is performed at the subsequent time t6. When the user wakes up, the state management task shifts the microcomputer to the sleep mode.

On the other hand, there are generally several types of factors (wakeup factors) that cause the microcomputer in the sleep mode to wake up (return to normal operation).
In the conventional microcomputer, when any wake-up factor occurs and wakes up, all application tasks are woken up.

For example, in the example of FIG. 7, the occurrence of some wake-up factor at time t1, the microcomputer wakes up from the sleep mode and wakes up the state management task. , 2 are all awakened. And even if the generated wake-up factor is related only to the application task 1, all of the application tasks 1 and 2 are woken up.
JP 2005-182223 A

  By the way, when the wake-up factor occurs, if all the app tasks are always woken up, the processing load on the microcomputer will increase unnecessarily, and until the next transition to sleep mode. There is a problem that the power consumption in the microcomputer increases accordingly.

  For example, in FIG. 7, if it is determined that the wake-up factor generated at time t1 is related only to the application task 1 and the application task 1 is in a sleep-enabled state at time t2, At t2, the microcomputer is in a state where it may shift to the sleep mode again.

  For this reason, it is sufficient that the microcomputer can be shifted to the sleep mode at time t4 when the state management task is subsequently woken up and the execution of the state management task is finished. However, the application task 2 is also woken up. Therefore, the transition timing to the sleep mode is extended to the above-described time t6. Therefore, a useless operation period as shown in FIG. 7 occurs, and useless processing and power consumption occur accordingly.

  The present invention has been made in view of these problems, and an object thereof is to suppress unnecessary processing and power consumption of a microcomputer.

  In order to achieve the above object, the microcomputer according to claim 1 executes a plurality of application tasks. The microcomputer also includes a determination unit that determines whether or not all application tasks need not be executed. If the determination unit makes an affirmative determination, the microcomputer consumes less power than during normal operation. Transition to less sleep mode.

In particular, this microcomputer is provided with a wake-up task wake-up control means.
When the microcomputer is in the sleep mode, the wake-up task wakeup control means generates any of a plurality of types of wake-up factors, and the microcomputer wakes up from the sleep mode. The generated wake-up factor is determined, and only the application task to be woken up when the determined wake-up factor occurs is woken up among the plurality of application tasks.

  According to such a microcomputer, when any of a plurality of types of wake-up factors occurs and a wake-up is performed from the sleep mode, an application task related to the generated wake-up factor (the wake-up factor) Only the application task that should be woken up when a factor occurs is woken up.

Therefore, unnecessary application tasks not related to the wake-up factor are not woken up, and the processing load is prevented from increasing unnecessarily.
Furthermore, since unnecessary application tasks are not woken up, the unnecessary application tasks are executed, and therefore it is delayed that the determination means makes an affirmative determination (determined that all application tasks need not be executed). It is possible to avoid the inconvenience such as. Therefore, the microcomputer can be shifted to the sleep mode at an appropriate time, and wasteful power consumption that has occurred in the prior art can be eliminated.

Next, in the microcomputer of claim 2, in the microcomputer of claim 1, the wake-up task wake-up control means is further configured as follows.
That is, the wake-up task wake-up control means includes a plurality of application tasks to be woken up, and among the plurality of application tasks, application tasks related to determination by the determination means (hereinafter referred to as first type tasks). If there is an application task not related to the determination by the determination means (hereinafter referred to as a second type task), and the second type task has a higher execution priority than the first type task, the microcomputer The execution priority order of the first type task and the second type task is changed only once immediately after the wake-up, so that the first type task is executed in preference to the second type task. To do.

  Note that an application task (second type task) that is not related to the determination by the determination means is a state in which other application tasks can sleep (a state that does not have to be executed) even if the application task is being executed. If so, it is a task that can be affirmed by the determination means.

  According to this configuration, after the microcomputer wakes up, if the determination means makes an affirmative determination if the execution of the first type task is completed, it is more effective than the second type task. Since the first type task is executed first, the determination means makes an affirmative determination earlier. Therefore, the microcomputer can be shifted to the sleep mode again earlier, and the possibility that wasteful processing and power consumption can be further suppressed can be increased.

  On the other hand, according to the program for causing the computer to function as the wake-up task wake-up control means, the microcomputer according to claims 1 and 2 can be realized without adding hardware.

  Further, the microcomputer according to claims 1 and 2 can be applied to various devices. However, particularly when used in a vehicle electronic control device for which reduction of power consumption is desired, the microcomputer in the vehicle electronic control device is useless. The power consumption can be further suppressed.

  Hereinafter, an electronic control device for a vehicle according to an embodiment to which the present invention is applied will be described. Note that the electronic control device of this embodiment is for controlling body-type equipment such as vehicle lamps and door locks. Hereinafter, the electronic control device is referred to as an ECU.

  As shown in FIG. 1, the ECU 11 according to the present embodiment includes a microcomputer 13, an input circuit 14 that inputs sensor signals and switch signals to the microcomputer 13, and drive signals to various actuators based on signals from the microcomputer 13. And a communication circuit 19 for the microcomputer 13 to communicate with the other ECUs 16 and 17 mounted on the vehicle via the communication line 18.

  Of the other ECUs 16 and 17, for example, the ECU 16 is a door ECU that controls a door lock or power window actuator provided on the door of the vehicle in cooperation with the ECU 11. The ECU 17 is a vehicle user. This is a verification ECU that performs verification communication with the electronic key carried by the mobile phone and notifies the ECU 11 of the verification result.

  In addition, the microcomputer 13 includes a well-known CPU 21, ROM 23, RAM 25, I / O port 27, and the like. The ROM 23 stores a program (software) executed by the CPU 21 in advance. In addition, the RAM 25 temporarily stores calculation results (for example, calculation result data and flags) obtained by executing the program.

  In the microcomputer 13, a plurality of application tasks (application tasks) for controlling the controlled object are executed by the multitask function of the OS. The application tasks include, for example, a communication processing task for communicating with other ECUs 16 and 17, a body main task for controlling body-related equipment, a timer task for elapse of time, and the like.

Further, the software stored in the ROM 25 of the microcomputer 13 includes a state management task MT in addition to the OS and application tasks.
As shown in FIG. 2, the state management task MT sends a wake-up request for the task to each of a plurality of application tasks AP1 to APx (x is 2 or more) when the timing at which the task should be executed has arrived. Is a task for performing a control for shifting the microcomputer 13 to the sleep mode upon detecting that the application does not have to be executed and all the application tasks AP1 to APx are executed.

  Among application tasks, there is a periodic application task that should be executed periodically. For this reason, the state management task MT is set to have a higher priority than the application tasks AP1 to APx, and is at least the least common divisor of the execution intervals of all the periodic application tasks while the microcomputer 13 is operating normally. It wakes up every time (in this embodiment, for example, every 1 ms).

  Among application tasks, there is also an event application task that should be executed when an irregular event occurs (for example, when a specific switch is turned on or when specific information is received from another ECU). . In the period during which the microcomputer 13 is normally operating, such an event application task is also requested to wake up by the state management task MT when the corresponding event occurs.

  Further, the state management task MT is woken up immediately when the microcomputer 13 wakes up from the sleep mode, and issues a wake-up request for an application task that needs to be executed at that time. Note that the wake-up factor (the factor causing the microcomputer 13 to wake up) includes, for example, that a specific switch has been turned on or that a signal from another ECU has been received.

  Next, processing contents of each application task (function realized by the application task) will be described with reference to the flowchart of FIG. Here, one application task APn (n is any one of 1 to x) will be described, but the same applies to other application tasks.

  When the execution of the application task APn is started, the processing of each application module that forms the application task APn is performed (S110). An application module is a program module that further subdivides the roles of application tasks, and each of the application tasks AP1 to APx includes one or more application modules.

  Then, when the processing of all application modules is completed (S120: YES), it is determined whether or not each of the application modules is in a sleep-enabled state that does not need to be executed (S130).

Here, for an application module, the sleep enabled state is a state in which the control realized by the application module is complete and it is not necessary to perform the control.
For example, in the case of an application module for controlling vehicle interior lighting, a series of controls related to vehicle interior lighting are realized by executing the application module a plurality of times at regular intervals. This is a state in which a series of controls have been completed, and there is no new control request, so that it is not necessary to perform the control. Some application modules do not have a series of controls, and when the execution of the application module is completed, the application module may be in a sleep-enabled state at any time.

  Then, when it is determined whether or not all the application modules are in the sleep-enabled state, it is determined whether or not the application task APn is in the sleep-enabled state based on the determination result (S140). Specifically, it is determined whether or not all application modules are in a sleep-enabled state. If all application modules are in a sleep-enabled state, it is determined that the application task APn is in a sleep-enabled state.

If it is determined that the application task APn is not in a sleep-capable state (S140: NO), the application task APn ends as it is.
On the other hand, when it is determined that the application task APn is in a sleepable state (S140: YES), a notification process for notifying the state management task MT that the application task APn is in a sleepable state. (S150), and then the application task APn ends. In the present embodiment, as the notification process, a process for setting a flag “Flag (n)” (hereinafter referred to as a sleep enable flag) is performed. Note that n in parentheses in the sleep enable flag is an identifier of the application task. Further, if the application task is “execution completed = sleeping possible state”, the determination process such as S130 and S140 may be omitted, and the process of S150 may be always performed at the end of the application task.

Next, processing contents of the state management task MT (functions realized by the state management task MT) will be described with reference to the flowchart of FIG.
As described above, the state management task MT is woken up at least at regular intervals while the microcomputer 13 is operating normally. In the state management task MT, the sleep control process in FIG. 4A is performed every time the microcomputer 13 wakes up and after the second execution.

That is, first, it is determined whether or not all sleep possible flags (Flag (1) to Flag (x)) of all the application tasks AP1 to APx are set (S210).
If the sleep possible flags of all the application tasks AP1 to APx are set (S210: YES), it is determined that it is not necessary to execute all the application tasks AP1 to APx and the sleep is possible. A process for shifting the microcomputer 13 to the sleep mode, which consumes less power than during normal operation, is performed without making a task wake-up request (S220). For example, the operation of an oscillation circuit that supplies a clock to the CPU 21 is stopped, or the operation of a power supply circuit that supplies power to the microcomputer 13 is stopped. For this reason, when the process of S220 is performed, the microcomputer 13 stops its operation. In S220, a process for lowering the clock frequency or power supply voltage of the CPU 21 may be performed.

  On the other hand, when a negative determination is made in S210 (that is, when any one of the sleep enable flags is not set), the processing of the state management task MT is finished as it is or other processing is performed. After that, the processing of the state management task MT ends.

  Depending on the application task, there is no problem even if the microcomputer 13 is shifted to the sleep mode during execution of the application task, and the application is not related to the sleep determination as to whether or not the sleep mode can be shifted. There are also tasks. And about the application task which is not related to the sleep determination, the sleep possible flag is always fixed to the set state. Further, the sleep enable flag of an application task other than an application task not related to sleep determination (an application task related to sleep determination) is reset when the application task is requested to wake up.

On the other hand, as described above, the state management task MT is woken up immediately when the microcomputer 13 wakes up from the sleep mode.
Then, in the state management task MT immediately after the wake-up, the wake-up process of FIG. 4B is performed.

That is, first, it is determined what is the current wake-up factor (S310).
More specifically, when a wake-up factor occurs while the microcomputer 13 is in the sleep mode, information indicating the occurrence of the factor is stored in an internal register (not shown) of the microcomputer 13 in hardware. At the same time, the microcomputer 13 returns to normal operation (that is, wakes up).

  For example, when a specific switch that becomes a wake-up factor is turned on and a level change of the switch signal is input to the microcomputer 13 via the input circuit 14, the microcomputer 13 wakes up and corresponds to the switch signal. 1 is set to the bit of the internal register. Further, for example, when the other ECUs 16 and 17 send a communication start signal indicating the start of communication to the communication line 18 and the communication start signal is detected by the communication circuit 19, a signal indicating that is sent from the communication circuit 19 to the microcomputer 13. The microcomputer 13 wakes up and 1 is set in the bit of the internal register corresponding to the communication start signal. For this reason, in S310, the wake-up factor is determined and specified by examining the bit that is 1 among the bits of the internal register.

  When the wake-up factor is specified in this way, among the application tasks AP1 to APx, the application task related to the wake-up factor specified this time (that is, should be woken up when the specified wake-up factor occurs). A wake-up request is issued only for the application task (S320). Thereafter, the processing of the state management task MT ends. For example, the ROM 23 stores data such as a table indicating each wake-up factor and an application task related to the wake-up factor. In S320, based on the data, the wake-up factor generated this time is stored. An application task related to the up factor (that is, an application task to be requested to wake up) is specified. When there are a plurality of application tasks related to the generated wake-up factor, a wake-up request is made for each application task.

Next, the effect | action of said each process is demonstrated using FIG. Here, it is assumed that there are an application task 1 and an application task 2 as application tasks.
In FIG. 5, the microcomputer 13 is in the sleep mode before time t1.

Then, it is assumed that a wake-up factor related only to application task 1 among application tasks 1 and 2 occurs at time t1.
Then, the microcomputer 13 wakes up and the state management task MT wakes up, and only the application task 1 related to the wake-up factor that has occurred this time is woken up by the processing of FIG. 4B. It will be requested (S310, S320).

  For example, if one of the application tasks 1 and 2 is the above-described communication processing task and the other is the above-described body main task, and the generated wake-up factor is a communication start signal from the other ECUs 16 and 17, the communication Of the processing task and the body main task, only the communication processing task is requested to wake up. Also, for example, if the generated wake-up factor is a door open detection switch that is a trigger for starting the control of the interior lighting of the vehicle, one of the communication processing task and the main body task that controls the interior lighting of the vehicle Only the main body task will be requested to wake up.

  Returning to FIG. 5, after that, when the execution of the state management task MT is completed, the application task 1 is executed. At the end of the application task 1 (time t2), the notification process of S150 in FIG. 3 is performed. .

  In this case, the state management task MT wakes up again at time t3 after a certain time from time t1, and the sleep control process of FIG. 4A is performed. In the sleep control process, “YES” is determined in S210. As a result, the process of S220 is performed. Therefore, the microcomputer 13 enters the sleep mode again at the time t4 when the execution of the current state management task MT ends.

  As described above, in the microcomputer 13 according to the present embodiment, when any one of a plurality of types of wakeup factors occurs and the wakeup is performed from the sleep mode, only the application task related to the generated wakeup factor is generated. Gets up. Therefore, the processing load is prevented from increasing unnecessarily.

  Furthermore, it is possible to avoid the inconvenience that an unnecessary application task is executed and that it is delayed in the sleep control processing (FIG. 4A) of the state management task MT that it is determined that sleep is possible. Therefore, the microcomputer 13 can be shifted to the sleep mode at an appropriate time, and the useless operation period and power consumption as illustrated in FIG. 7 can be eliminated.

In the present embodiment, since the wake-up process in FIG. 4B is realized by a program, the above effect can be obtained without adding hardware.
And according to ECU11 provided with such a microcomputer 13, the power consumption when it does not need to operate can be controlled more than before.

  In the present embodiment, among the processes of the state management task MT, the process of S210 in FIG. 4A corresponds to the determining means, and the process of FIG. 4B is used as the wake-up task wake-up control means. It corresponds.

Next, a second embodiment will be described. Here, a different part from the previously described embodiment (first embodiment) will be described.
As described above, when there are a plurality of application tasks related to the wake-up factor in S320 of FIG. 4B, the microcomputer 13 issues a wake-up request for each application task. In the form, each application task is executed in the same priority order as in the normal state.

  On the other hand, in the microcomputer 13 of the second embodiment, when there are a plurality of application tasks (hereinafter referred to as wake-up request target tasks) related to the wake-up factor in S320 of FIG. Process.

  First, among a plurality of wake-up request target tasks, there are application tasks related to sleep determination and application tasks not related to sleep determination, and application tasks not related to sleep determination are more related to sleep determination. It is determined whether or not the execution priority is higher than the application task.

  If the determination is affirmative, the execution priority of the application task related to the sleep determination and the application task not related to the sleep determination is changed only once immediately after the wake-up of the microcomputer 13. Then, the setting is changed so that the application task related to the sleep determination is executed in preference to the application task not related to the sleep determination, and then a wake-up request is made for each application task.

  According to the second embodiment, after the microcomputer 13 wakes up, if the execution of the application task related to the sleep determination is completed, it is determined that the sleep is possible in S210 of FIG. If the situation is such that the application task related to sleep determination is executed earlier than when the priority order is not changed, it is determined that sleep is possible earlier. Therefore, the microcomputer 13 can be shifted to the sleep mode again earlier, and the possibility that wasteful processing and power consumption can be further suppressed can be increased.

A specific example is shown in FIG.
In FIG. 6, although the application task a has a higher priority than the application task b, the processing contents depend on the application task b and are not related to sleep determination (the sleep enable flag is fixed to the set state). Task). In other words, the application task a is a task that does not have any trouble if it is not executed if the application task b is in a sleepable state. In this example, upon receiving a processing request from the application task b, the application task a is sent to the other ECUs 16 and 17. It is a task that performs processing for transmitting information.

  The application task b is a timer task for measuring time. The application task b counts the number of times the microcomputer 13 has woken up by a periodic activation signal from an external timer circuit (not shown), and the count value is a specified value N. If it is not set, the sleep enable flag of the own task is set as it is, but when the count value reaches the specified value N, the task is a task for requesting the application task a without setting the sleep enable flag.

  For example, the microcomputer 13 is woken up every predetermined time T1 (for example, 10 seconds) by a periodic activation signal from an external timer circuit. Then, the application task b is woken up every time the external timer circuit wakes up, and the application task b counts the number of wake-ups by the external timer circuit as the count value. Further, in the application task b, when the count value reaches the specified value N, it is determined that the time “T1 × N” has elapsed, and a processing request is made to the application task a. Then, the application task a performs a process of transmitting information to the other ECUs 16 and 17.

  Here, at time t1 in FIG. 6, the microcomputer 13 wakes up by the periodic activation signal from the external timer circuit, and the state management task MT performs the wakeup factor of the periodic activation signal by the processing in FIG. 4B. Assume that a wake-up request is made for the application tasks a and b related to. Further, even if the application task b counts up the count value at this time, the count value has not yet reached the specified value N.

  In this case, as shown in FIG. 6A, if the priority order of the application tasks a and b is not changed, the application task a is executed before the application task b. The time from when the microcomputer 13 wakes up until the sleep enable flag is set in the application task b becomes longer, and as a result, until the state management task MT determines that sleep is possible (that is, the microcomputer 13 is again connected). It takes longer time to enter sleep mode. In the example of FIG. 6A, during the execution of the application task b executed after the application task a, the next state management task MT is interrupted at time t2, and the next state management task MT is further processed at time t3. Is executed, the microcomputer 13 is determined to be able to sleep, and the microcomputer 13 has shifted to the sleep mode.

  On the other hand, in the second embodiment, as shown in FIG. 6B, the priority order of the application tasks a and b is reversed only once immediately after wakeup. For this reason, the application task b is executed before the application task a. As a result, the time from when the microcomputer 13 wakes up until the sleep enable flag is set in the application task b is shortened. Therefore, the time from when the microcomputer 13 wakes up to the state management task MT is determined to be sleepable until the sleep mode is entered again is shortened, and power consumption is reduced. In the example of FIG. 6B, since the application task b sets the sleep enable flag before the time t2 when the second state management task MT is executed after the microcomputer 13 wakes up, the time t2 When the state management task MT is executed, it is determined that sleep is possible, and the microcomputer 13 shifts to the sleep mode.

As described above, according to the second embodiment, it is possible to speed up the transition to the sleep mode, and it is possible to further suppress unnecessary processing and power consumption.
As mentioned above, although one Embodiment of this invention was described, this invention is not limited to such Embodiment at all, Of course, in the range which does not deviate from the summary of this invention, it can implement in a various aspect. .

For example, the OS may have a function of the state management task MT.
Further, the state management task MT may be executed in any application task. In other words, a certain application task may control task wakeup or the like instead of the state management task MT.

  On the other hand, the present invention is not limited to the ECU that controls the functions of the body system as described above, but can be applied to, for example, an ECU that controls a powertrain system such as an engine or a transmission. The same applies to the ECU.

It is a figure showing the structure of the electronic controller for vehicles (ECU) of embodiment. It is a figure showing the software configuration performed with a microcomputer. It is a flowchart showing the processing content of each application task. It is a flowchart showing the processing content of a state management task. It is explanatory drawing explaining the effect | action by the process of FIG.3 and FIG.4. It is explanatory drawing explaining the specific example of 2nd Embodiment. It is explanatory drawing explaining a prior art and its problem.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 11, 16, 17 ... ECU, 13 ... Microcomputer, 14 ... Input circuit, 15 ... Output circuit, 18 ... Communication line, 19 ... Communication circuit, 21 ... CPU, 23 ... ROM, 25 ... RAM, 27 ... I / O port , AP1 to APx ... application task, MT ... state management task

Claims (4)

A plurality of application tasks are executed, and a determination means for determining whether or not all application tasks need not be executed is provided. When the determination means makes an affirmative determination, In a microcomputer that shifts to sleep mode with low power consumption,
When the microcomputer is in the sleep mode, if any of a plurality of types of wake-up factors occurs and the microcomputer wakes up from the sleep mode, the generated wake-up factor is determined. A wake-up task wake-up control means for waking up only the application task to be woken up when the determined wake-up factor occurs among the plurality of application tasks,
A microcomputer characterized by. The microcomputer according to claim 1,
The wake-up task wake-up control means includes:
There are a plurality of application tasks to be woken up, and among the plurality of application tasks, an application task related to the determination by the determination unit (hereinafter referred to as a first type task) and not determined by the determination unit If there is an application task (hereinafter referred to as a second type task) and the execution priority of the second type task is higher than that of the first type task, 1 immediately after the microcomputer wakes up. Changing the execution priority of the first type task and the second type task only once, so that the first type task is executed in preference to the second type task,
A microcomputer characterized by.   The program for functioning a computer as a wake-up task wake-up control means according to claim 1 or 2.   An electronic control device for a vehicle comprising the microcomputer according to claim 1.

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