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External timer trigger on STM8S003_F_?

Question asked by Philip on Nov 20, 2015
Hi!

I have to generate a PWM that must  be quite closely synced to an external signal of 50 Hz (to avoid any drifts).
From the documentation contents of STM8S008F/K of it using the TIM1 external trigger (ETR) to reset the PWM/Timer counter (and relying on the commutation event to implement some stepwise updates of the PWM) would be the optimal way to go.

Alas, as of my understanding, the STM8S003microchip does not have a TIM1 external trigger pin (TIM1_ETR) that can be selected as trigger source.

The alternative would be to rely on high priority interrupts. I would like to avoid this to interfere as little as possible on the other software components (essential decoding of a signal), although at 50Hz that might be negligible - not tested yet.

So my question ultimately being: Did I miss something and there effectively is an pin-in that I can use as trigger source for TIM1 on the chip or is there some other approach to sync the PWM that I do not see?

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