KR20030027458A - System and method for monitoring using watchdog timer in rtos - Google Patents

Abstract

PURPOSE: A system and method for monitoring a malfunction using a watch dog timer in an RTOS(Real-Time Operating System) is provided to reset the watch dog timer continuously and to prevent the watch dog timer from booting again a system in a critical area by creating a watch dog timer task when the watch dog timer is initialized. CONSTITUTION: A watch dog timer(20) is reset periodically by receiving a reset signal from a control unit(10). When a reset signal is not inputted from the control unit(10) within a predetermined time, the watch dog timer(20) boots a system. A watch dog timer task module(13) outputs a reset signal for reproducing the watch dog timer(20) continuously. A watch dog timer initialization module(12) stops the watch dog timer(20) in a system hardware initialization, resets a variable value of the watch dog timer(20), creates a watch dog timer task module, and operates the watch dog timer(20). A critical area process interrupt module(14) outputs a stop signal to the watch dog timer(20) before a critical area. When a critical area is removed, the critical area process interrupt module(14) outputs a driving signal to the watch dog timer(20).

Description

Malfunction monitoring system and method using watchdog timer in RTOSS {SYSTEM AND METHOD FOR MONITORING USING WATCHDOG TIMER IN RTOS}

The present invention relates to a malfunction monitoring system and method using a watchdog timer in an RTOS, and more particularly, generates a watchdog timer task when the watchdog timer is initialized so that the watchdog timer is continuously played and processes a critical area. System and method.

Programming methods used in the conventional embedded system are largely a conventional sequential execution programming method of the foreground / background method and a single tasking / multi-tasking method using an operating system (OS).

The sequential execution method is used in many microcomputer applications, and this method is a program written in order that all programs flow sequentially except for interrupt processing.

In addition, the programming method using the OS is similar to the sequential execution method in the case of the single tasking method, except that a kernel for loading, executing, and managing a program exists.

Likewise, this method causes all programs to flow sequentially except for interrupt processing. A typical example is DOS (Disk Operating System).

The multi-tasking method has several advantages that the program can be easily implemented and the convenience of the task can be increased by performing appropriate tasks while the programs are realized on one OS. Unix and RTOS are typical examples.

This timer is used to check the computer hardware for abnormality. In normal condition, it is repeatedly reset by the program in shorter time than the monitoring time, but when it is not reset due to abnormal condition, a warning is issued. This timer is set when processing is delayed due to a fault or a program error.

In the case of the sequential execution method and the single tasking OS, two methods have been traditionally used to monitor a system using a watchdog timer.

The first is to set the watchdog timer on the sequential program to notify the watchdog timer that the system is operating normally.

The second method is to put a watchdog timer reset command inside the timer interrupt routine of the system and call the timer interrupt routine at regular intervals to notify the watchdog timer that the system is operating normally.

However, as described above, the conventional technique is also used in the RTOS. In the first case, since the timer must be cleared for each code, the program code becomes large and optimization cannot be achieved. In the second case, the threshold is due to the characteristics of the RTOS. There was a problem that area processing became difficult.

Accordingly, the present invention has been made to solve the above-mentioned conventional problems, and generates a watchdog timer task when the watchdog timer is initialized so that the watchdog timer is continuously reset as well as the watchdog timer in the critical region. An object of the present invention is to provide a malfunction prevention system and method using a watchdog timer in an RTOS to prevent a system reboot.

An embodiment of the present invention for achieving the above object is a malfunction monitoring system in the RTOS using a watchdog timer that is reset by a signal continuously output from the control unit, the system reboots when the reset signal is not received The watchdog timer task module may further include: a watchdog timer task module configured to continuously output a reset signal to reproduce the watchdog timer; And a watchdog timer initialization module configured to stop the watchdog timer, reset the variable value of the watchdog timer, and generate the watchdog timer task module and drive the watchdog timer. It features.

Another embodiment of the present invention for achieving the above object, the watchdog timer is stopped during system hardware initialization, after resetting the variable value of the watchdog timer, and generates the watchdog timer task, the watchdog A watchdog timer initialization step of driving a timer; And a watchdog timer task step of continuously outputting a reset signal to reproduce the watchdog timer.

1 is a block diagram of a malfunction monitoring system using a watchdog timer in an RTOS according to the present invention;

2 is a flowchart illustrating a malfunction monitoring method using a watchdog timer in an RTOS according to the present invention;

3 is a flowchart illustrating a watchdog timer initialization process according to the present invention.

4 is a flowchart illustrating a process of performing a watchdog timer task according to the present invention.

5A and 5B are flowcharts illustrating a critical region processing process according to the present invention.

** Description of symbols for the main parts of the drawing **

10 control unit 11: main module

12: watchdog timer initialization module 13: watchdog timer task module

14: critical area processing module 20: watchdog timer

Hereinafter, an embodiment according to the present invention will be described in detail with reference to the accompanying drawings.

1 is a block diagram of a malfunction monitoring system using a watchdog timer in an RTOS according to the present invention.

Referring to FIG. 1, a malfunction monitoring system using a watchdog timer in an RTOS according to the present invention is periodically reset by receiving a reset signal from the controller 10 and the controller 10, and from the controller 10. The watchdog timer 20 is configured to reboot the system when the reset signal is not input within a predetermined time.

The control unit 10 is composed of a main module 11 to be executed according to the system drive, and a module called and executed by the main module 11 and each module, the modules are executed at the same time the hardware is initialized The watchdog timer initialization module 12 and the watchdog timer task module 13 generated by the watchdog timer initialization module 12 to continuously reset the watchdog timer 20. And a threshold region processing interrupt module 14 for generating an interrupt signal to prevent a system reboot of the timer.

The operation of each module will be described in detail in a malfunction monitoring method using a watchdog timer in an RTOS, which will be described later.

2 is a flowchart illustrating a malfunction monitoring method using a watchdog timer in an RTOS according to the present invention.

Referring to FIG. 2, the present invention provides a malfunction monitoring method using a watchdog timer in an RTOS. The watchdog timer is stopped when system hardware is initialized, and the variable value of the watchdog timer is reset. Generating and driving the watchdog timer (S100 to S200); Continuously outputting a reset signal to reproduce the watchdog timer (S300); When the critical region occurs, generating an interrupt signal for preventing the system reboot of the watchdog timer (S400 ~ 500).

Hereinafter, the operation description on the above-described system will be described in detail.

When the system hardware is initialized while the RTOS kernel is loaded (S100), the controller 10 executes a watchdog timer initialization process (S200). FIG. 3 is a flowchart illustrating a watchdog timer initialization process according to the present invention. The operation description by the watchdog timer initialization module will be described in more detail with reference to FIG. 3 as follows.

The watchdog timer initialization module 12 determines whether the initialization flag is set to '1' (S210). If the initialization flag is set as a result of the determination, the watchdog timer initialization module 12 stops executing the initialization module and exits the initialization routine.

However, as a result of the determination in S210, if the initialization flag is not set, the watchdog timer is stopped (S220), the operation mode is set in the timer control register (S230), and a value to be reloaded is written in the timer variable register. (S240).

In addition, the watchdog timer initialization module 12 generates a timer task having a highest rank (S250), and then continuously performs a timer task, sets the timer initialization flag, and resets the watchdog timer. Drive (S260).

An embodiment of a program source for implementing the aforementioned watchdog timer initialization process is as follows.

int wdt_init (void)

{

if (wdt_initialized) return (ERROR);

wdt_stop ();

wdt_mode_set ();

wdt_reload_value_set ();

if (taskSpawn ("tWdtTask", 0, 0, 512, (FUNCPTR) wdt_refresh_task, 0, 0, 0,

0, 0, 0, 0, 0, 0, 0) == ERROR) return (ERROR);

wdt_initialized = 1;

wdt_restart ();

return (OK);

}

The operation of the watchdog timer task module 13 of the watchdog timer generated during the watchdog timer initialization process will be described with reference to FIG. 4. First, the watchdog timer is stopped (S310), and the timer is again driven ( After executing the watchdog timer regeneration routine, the task is delayed within the timer reset interval (S330), and then the process returns to S310 again to repeat the above process.

An embodiment of a program source for implementing the watchdog timer task described above is as follows.

void wdt_refresh_task (void)

{

while (1)

{

wdt_refresh ();

taskDelay (sysClkRateGet () / 5); / * 200 ms task delay * /

}

}

void wdt_refresh (void)

{

wdt_stop ();

wdt_restart ();

}

As described above, the watchdog timer task does not operate in the critical area while the timer is continuously reset. Therefore, the watchdog timer should be prevented from rebooting the system in a proper way to ensure normal operation. You can use Interrupt Service Routine (ISR), Interrupt Locking, and Task Locking.

5A and 5B are flowcharts for describing a critical area processing process. Referring first to FIG. 5A, after the timer is stopped (S510), the main routine is executed (S520), and when the main routine is finished, again The watchdog timer is driven (S530).

An embodiment of a program source implementing the first method described above is as follows.

void flash_write (void)

{

wdt_stop ();

... / * main routines * /

wdt_restart ();

}

Secondly, referring to FIG. 5B, the watchdog timer regeneration routine is continuously executed (S510 ′), and it is determined whether the threshold is out of the threshold region (S520 ′). Terminate a process.

An embodiment of a program source implementing the above-described second method is as follows.

void flash_wait_done (void)

{

do {

wdt_refresh ();

... / * main routines * /

} while (wait_done);

}

The present invention is not limited to the embodiments described above, and various modifications and changes can be made by those skilled in the art, which are included in the spirit and scope of the present invention as defined in the appended claims.

As described above, the present invention not only increases the reliability of the system by creating and maintaining a watchdog timer task, but also provides a processing method in a critical section due to the characteristics of the RTOS so that the system is rebooted by the watchdog timer. It is effective in preventing down symptoms.

Claims (6)

In the malfunction monitoring system in the RTOS using a watchdog timer that is reset by a signal continuously output from the control unit and reboots the system when the reset signal is not received, the control unit A watchdog timer task module configured to continuously output a reset signal to reproduce the watchdog timer; And a watchdog timer initialization module configured to stop the watchdog timer upon system hardware initialization, reset the variable value of the watchdog timer, generate the watchdog timer task module, and drive the watchdog timer. Malfunction monitoring system using a watchdog timer in RTOS. The method of claim 1, wherein the control unit And a threshold region processing interrupt module configured to output a stop signal to the watchdog timer before the threshold region and then output a driving signal to the watchdog timer when the watchdog timer is out of the threshold region. Malfunction monitoring system using dock timer. The method of claim 1, wherein the control unit And a threshold region processing interrupt module configured to continuously reproduce the watchdog timer in a critical region. A watchdog timer initialization step of stopping the watchdog timer upon system hardware initialization, resetting a variable value of the watchdog timer, generating the watchdog timer task, and driving the watchdog timer; And a watchdog timer task step of outputting a reset signal to continuously reproduce the watchdog timer. The method of claim 4, wherein And a threshold region processing interrupt step of outputting a stop signal to the watchdog timer before a threshold region, and outputting a driving signal to the watchdog timer when the watchdog timer is out of the threshold region. Malfunction monitoring method. The method of claim 4, wherein And a threshold region processing interrupt step of continuously regenerating the watchdog timer in a threshold region.