what is the smallest achievable delay in microseconds for a 16-bit and a 32-bit timer?

[Berlin-raj123]

Hi, I want to generate a 1 microsecond (1 µs) timer interrupt on the STM32G0B1RCT6 microcontroller using its internal clock(16MHz). I am currently using a 16-bit timer to achieve a 5 microsecond delay, but I cannot achieve a 1 microsecond delay. My question is: what is the smallest achievable delay in microseconds for a 16-bit and a 32-bit timer?

[Andrew Neil]

You've already got a thread on this:

https://community.st.com/t5/stm32-mcus-boards-and-hardware/how-to-generate-a-1-microsecond-1-%C2%B5s-timer-interrupt-on-the/m-p/684321#M19430

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@Berlin-raj123 wrote:

Hi, I want to generate a 1 microsecond (1 µs) timer interrupt 

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In that thread, several people have already asked you why you feel the need to do that, and have explained that it's a Bad Idea.

[Tesla DeLorean · Accepted solution]

This was already explained too you. You can't interrupt at this rate, you basically saturate the processors with busy work, and nothing gets done.

What you can do is have a maximal counter, running as fast as the processor clock, so whatever quantum that factors out at.

ie TIM->PSC = 0, TIM->ARR=0xFFFF

For a TIM clock running at 48 MHz, TIM->CNT increments every 20.833 ns

uint16_t start = TIM1->CNT;

while((TIM1->CNT - start) < 48); // 1us at 48 MHZ

[SofLit]

Hello @Berlin-raj123 

Could you please tell why are you duplicating this thread from https://community.st.com/t5/stm32-mcus-boards-and-hardware/how-to-generate-a-1-microsecond-1-%C2%B5s-timer-interrupt-on-the/m-p/684321#M19430 ?

Are all these answers didn't convince you?

I agree with @Tesla DeLorean you will saturate the processor at this rate for nothing as you didn't explain the main reason for doing that!

Otherwise the thread will be closed.