RM0316 Datasheet, PDF (623/1141 Pages) STMicroelectronics – This reference manual targets application developers

RM0316
General-purpose timers (TIM2/TIM3/TIM4)
Note:
detected (sampled at f_DTS frequency). Then write IC1F bits to 0011 in the
TIMx_CCMR1 register.
3. Select the edge of the active transition on the TI1 channel by writing the CC1P and
CC1NP and CC1NP bits to 000 in the TIMx_CCER register (rising edge in this case).
4. Program the input prescaler. In our example, we wish the capture to be performed at
each valid transition, so the prescaler is disabled (write IC1PS bits to 00 in the
TIMx_CCMR1 register).
5. Enable capture from the counter into the capture register by setting the CC1E bit in the
TIMx_CCER register.
6. If needed, enable the related interrupt request by setting the CC1IE bit in the
TIMx_DIER register, and/or the DMA request by setting the CC1DE bit in the
TIMx_DIER register.
When an input capture occurs:
• The TIMx_CCR1 register gets the value of the counter on the active transition.
• CC1IF flag is set (interrupt flag). CC1OF is also set if at least two consecutive captures
occurred whereas the flag was not cleared.
• An interrupt is generated depending on the CC1IE bit.
• A DMA request is generated depending on the CC1DE bit.
In order to handle the overcapture, it is recommended to read the data before the
overcapture flag. This is to avoid missing an overcapture which could happen after reading
the flag and before reading the data.
IC interrupt and/or DMA requests can be generated by software by setting the
corresponding CCxG bit in the TIMx_EGR register.
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