STM32F4: What is the max speed (but working) of encoder interface mode?

[yonatan]

Posted on June 16, 2016 at 08:09

Hi all.

In our system we use one of the general purpose timers in ''Encoder interface mode'', that means, the encoder clocks the timer counter to count the pulses. I found this in the documentation:

''Encoder interface mode acts simply as an external clock with direction selection''

So my question is - what is the max frequency of incoming PWM (from the encoder) That the timer counter would still work? Does that means that the timer internal clock (sourced by sysclk) does not affect this mode?? Thank all for replying... #timer #encoder

[waclawek.jan]

Posted on June 16, 2016 at 09:15

The STM32 timers are fully synchronous, including sampling their inputs, so the clock coming from RCC as you mentioned still limits the maximum input frequency. In encoder mode, the edges must always be at least one clock apart.

JW