STM8S003F3 tim2 configuration

Question

I am using STM8S Cosmic C compiler, and I am trying to configure tim2 for 350 µs (350 µs should be the pulse width).

As per the reference manual, tim4 is a 16-bit with a prescaler factor of 32768. I will be using the internal 2 MHz clock

My calculations are as follows:

1/2000000 Hz = 0.0000005 seconds ~ 0.5 µs
If we use a 128 prescaler:
128 * 0.5 µs = 64 µs

I want each pulse to be of 350 µs, how do I calculate that? Are the calculations are wrong too?

I am trying to calculate it for 350 µs, but I am not getting actual value and need guidance!

Reduce prescaler to 1 to get a timebase of 0.5us. The ARR register has to be loaded with 350us/0.5us - 1= 700 - 1= 699. — Patrick Joseph
– Patrick Joseph, Commented Aug 11 at 3:26

Peter Mortensen · Accepted Answer · 2025-08-11 02:54:14Z

0

Use the lowest value of the prescaler.

As you mentioned, tim2 is 16 bit. So you have the span of 65535 counts. Without a prescaler (2^0), the counter can reach a value of 700 (for 350 µs).

It depends on the accuracy you want. I would not use a prescaler for these settings.

edited Aug 11 at 2:54

Peter Mortensen

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answered Jul 16, 2023 at 12:03

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