Hello,
i found a strange behavior having 2 timers running.
My initial intention was having 4 input captures on the 32F746GDISCOVERY spread over two timers (no timer with 4 pins connected to the Arduino Header) one running as master and triggering the same start.
I always got phase drift between channels. So I stripped down everything to identify he issue in detail.
Timer 8 on APB2 (200MHz) and Timer 4 running on APB1 (100MHz) are both configured as basic timer with high presclaer. Timer 8 has two times prescaler value than Timer 4.
I would expect both timers showing always the same value (+-1 or 2) since the prescaler is 10000 / 20000 is running the timer very slow compared to the register access.
What I observe is that the timers started at the same time start to drift away from each other.
What is the reason for this difference. Is there a bug in one of the Clock multipliers?
Please find the test configuration attached.
Also a log file is attached.
If instead of TIM8 the TIM3 (on APB1) is used there is no drift compared to TIM4.
Thanks a lot,
Daniel Schramm
