STM32 Systick Timer

/* Auszüge aus meiner main.c: */

void TimingDelay_Decrement(void);

uint8_t systick_delay_var=0;

int main()

{

    SystemInit();

    /* Setup SysTick Timer for 1 msec interrupts  */

    if (SysTick_Config((72000000 / 1000)))

    { 

        /* Capture error */ 

        while (1);

    }

    while(1)

    {

        systick_delay_var=100;

        /* Tue etwas... */

        /* Warte */

        while(systick_delay_var!=0);

    }

}

void TimingDelay_Decrement(void)

{

  if (systick_delay_var != 0)

  { 

    systick_delay_var--;

  }

}

/* Auszüge aus meiner stm32f10x_it.c: */

extern void TimingDelay_Decrement(void);

void SysTick_Handler(void)

{

    TimingDelay_Decrement();

}