The clocks each command takes

[Arman Ilmak]

Posted on April 27, 2018 at 19:51

Hi.

I wanted to know that for example how many clocks a while loop takes.

Do you have any ideas or any articles on this matter?

Note: this post was migrated and contained many threaded conversations, some content may be missing.

[Tesla DeLorean]

Posted on April 28, 2018 at 22:44

If you set the TIM to clock at 1 MHz you can observe intervals with 1us granularity by looking at the CNT value. You can interrupt at such rates.

start = TIM->CNT;

while((TIM->CNT - start) < 100); // Wait 100us

[Arman Ilmak]

Posted on May 04, 2018 at 11:45

void delay_us(unsigned int d)

{TIM2_Cmd(ENABLE);while( ((TIM2->CNTRL)|((TIM2->CNTRL)<<8))<=d);TIM2_Cmd(DISABLE);TIM2->CNTRL=0;TIM2->CNTRH=0;}

void delay_ms(unsigned int d)

{while(d){d--;delay_us(1000);}}

I've written this code for my delay functions but they do not work.

The timer CNT counts each 1 us.

[henry.dick]

Posted on May 04, 2018 at 11:58

Run your led update function through a timer isr so it is not blocked by the 1wire routines.

[Arman Ilmak]

Posted on May 04, 2018 at 17:33

I didn't understand what you mean.

[Tesla DeLorean]

Posted on May 04, 2018 at 17:44

I'm not advocating the repeated resetting and enabling/disabling the timer. I'm saying to let it free run and delta the current and start points.

If dealing with 8-bit values is most effective on the STM8 (not using, don't plan too), then perhaps decompose the delays into 200us or 100us pieces so the code is tighter and the opportunity for jitter reduced.

[Arman Ilmak]

Posted on May 04, 2018 at 18:00

You mean with these 8-bit MCUs I cant get a 1 us delay using the timer?

[henry.dick]

Posted on May 04, 2018 at 20:29

take some classes in embedded programming.

you are going down a path that can only hurt your learning in the long run.

[Arman Ilmak]

Posted on May 04, 2018 at 21:25

If I had the possibility I would do that.But these classes will not be free and as a student, I can't afford the expenses.

[Bogdan Golab]

Posted on May 04, 2018 at 21:34

There are some classes available for free. Look at edX and similar initiatives:

https://www.edx.org/course/embedded-systems-shape-the-world-microcontroller-inputoutput

 

also books are good way of learning and verifying the knowledge in practice.

[henry.dick]

Posted on May 04, 2018 at 22:43

'

I can't afford the expenses.'

it is a tough spot to be in, unfortunately.

with that said, you may want to focus a little bit on the basics before tackling issues outside of your skill set.

slowing down now often allows you to run faster later.