Posted on May 12, 2018 at 15:32I just used RTC interrupt to measure msec timing. and I got some problem.
when i write naive code in interrupt there is no problem. timing is correct and no delay. the sample code is below
void RTC_IRQHandler(void)
{
val = RTC->CNTL ;
dif = val - ex;
msec++;
if (msec >= 1000)
{
sec++;
msec = 0;
}
ex = RTC->CNTL ;
}
but when i use a function to replace with the code the timing have delay almost half
void RTC_IRQHandler(void)
{
val = RTC->CNTL ;
dif = val - ex;
timing(); // just same with previous code.
ex = RTC->CNTL ;
}
void timing()
{
msec_++;
if (msec_ >= 1000)
{
sec_++;
msec_ = 0;
}
}
to clarify, i write the two code in same time. but change nothing
void RTC_IRQHandler(void)
{
val = RTC->CNTL ;
dif = val - ex;
msec++;
if (msec >= 1000)
{
sec++;
msec = 0;
}
timing(); // the timing is same and also has same delay
ex = RTC->CNTL ;
}
wtf? I didn't change any clock config. why this interrupt is not occur in correct timing when i use any simple function?
