Getting an delay by timer interruption

[david.ye]

Posted on November 13, 2017 at 17:44

Hello Everyone,

I am working on the STM8AL3166 and try to handle a timer interrupt. My need is to wait 500ms and then check again a value (not pooling)

How/Where do I write the program when the interrupt occurs? Where can I find the header file?

I did several hours of searching and can not find anything, Please Help !

Thank,

David

#timer-interrupts #delay

[Vyacheslav Azarov]

Posted on November 15, 2017 at 10:03

Ask please the question more fully. It's hard to understand what you want. Usually, a non-blocking delay in computation is possible only in a multitasking environment.

[david.ye]

Posted on November 15, 2017 at 10:33

Hello,

Thank for the reply.

Let me rephrase my question : how do we get into the interrupt service routine?

I configured my timer as below

...

void InitTIM4(){

       TIM4_CR1= 0x04;       //Counter stops counting at the next update event (clearing the CEN bit)

       TIM4_IER= 0x01;         //enable interrupt

       TIM4_PRSCR=0xFE   //Fsysclk divided by 2^13 => timer tick= 1,024ms

}

...

   if(value==1){

        TIM4_CRR1=0x0A;   //interrupt in10ms

        TIM4_CR1=0x05;      //active the timer

...

Then how can I go into the interrupt service routine to tell him what to do when the interrupt occurs? which function to call? Do I need to import a specific library? 

Thank a lot in advance,

David

[S.Ma]

Posted on November 15, 2017 at 10:56

For 500msec or msec units, you can add your function inside the Systick() milisecond event. There you can countdown a global variable and when the variable reaches zero, you do something or raise a flag (a bit). The main loop can change the global countdown variable and when it reaches zero, the main loop will see a flag set, do the job and clear the flag, optionally rearm the countdown. Using HW Timer would be for finger time granularity (microseconds)

[david.ye]

Posted on November 15, 2017 at 11:15

Hi,

Where can I find the Systick() millisecond event function? which library I have to download?

I am really not used to control time in programmation :\

Many thanks

[Vyacheslav Azarov]

Posted on November 15, 2017 at 11:31

In different compilers, interrupt service routines are declared differently. In any case you need to describe ISR logic by himself.

//SDCC:
void YourISRname(void) __interrupt(YOUR_VECTOR)
{
// ... Your logic
}
//COSMIC:
// is need to insertion this name in the special table
@interrupt void YourISRname(void)
{
// ... Your logic
}
//IAR:
#pragma vector = YOUR_VECTOR
 __interrupt void YourISRname(void)
{
// ... Your logic
}�?�?�?�?�?�?�?�?�?�?�?�?�?�?�?�?�?�?�?

Read compiler manual, please.

[david.ye]

Posted on November 15, 2017 at 16:34

Hello,

Thank you for this answer.

I am using Raisonnance, Ride 7 IDE.

I will read their compiler manual.

Regards

[david.ye]

Posted on November 16, 2017 at 08:26

Hello Vyacheslav,

I have read the manual and found my need. The syntax is :

void MyISRName(void) interrupt MyVectorNb

{ // My algorithm }

But I still have one question about the IDE. Is generally the simulator can simulate a timer? Because when I am debugging my code, the PC never goes into the interrupt handler.

Edit:

As a reminder, this is my program in pj.

Many thanks,

David

________________ Attachments : codeTimer.PNG : https://st--c.eu10.content.force.com/sfc/dist/version/download/?oid=00Db0000000YtG6&ids=0680X000006HyIU&d=%2Fa%2F0X0000000b5h%2FCuFOQxsUME53knGN29w9obWBEq.USRBPhllBoTkYKF0&asPdf=false

[Vyacheslav Azarov]

Posted on November 16, 2017 at 09:30

I do not know as it is realized at Raisonnance. But the IAR-EW and ST-VD simulation of the periphery has not  fully implemented. Requires the definition of interrupt events manually, by writing to a special table.

[Pavel A.]

Posted on November 18, 2017 at 05:04

Systick() is a feature of ARM (STM32) libraries. STM8 libraries do not have it, roll your own.

- pa