![]() ![]() Enable capture from the counter into the capture register by setting the CC1E bit in the TIMx_CCER register. So the prescaler is disabled (write IC1PS bits to ‘00’ in the TIMx_CCMR1 register). ![]() In our example, we wish the capture to be performed at each valid transition, In the TIMx_CCER register (rising edge in this case). Select the edge of the active transition on the TI1 channel by writing CC1P and CC1NP bits to 0 Then write IC1F bits to 0011 in the TIMx_CCMR1 register. We can validate a transition on TI1 when 8 consecutive samples with the new level have been detected (sampled at fDTS frequency). We must program a filter duration longer than these 5 clock cycles. Let’s imagine that, when toggling, the input signal is not stable during at must 5 internal clock cycles. (by programming ICxF bits in the TIMx_CCMRx register if the input is a TIx input). Program the input filter duration you need with respect to the signal you connect to the timer TIMx_CCR1 must be linked to the TI1 input, so write the CC1S bits to 01 in the TIMx_CCMR1 register.Īs soon as CC1S becomes different from 00, the channel is configured in input and the TIMx_CCR1 register becomes read-only. The following example shows how to capture the counter value in TIMx_CCR1 when TI1 input rises. If a capture occurs while the CCxIF flag was already high, then the over-capture flag CCxOF (TIMx_SR register) is set.ĬCxIF can be cleared by software by writing it to ‘0’ or by reading the captured data stored in the TIMx_CCRx register.ĬCxOF is cleared when you write it to ‘0’. Or a DMA request can be sent if they are enabled. When a capture occurs, the corresponding CCXIF flag (TIMx_SR register) is set and an interrupt In Input capture mode, the Capture/Compare Registers (TIMx_CCRx) are used to latch the value of the counterĪfter a transition detected by the corresponding ICx signal. It is prescaled before the capture register (ICxPS). Which can be used as trigger input by the slave mode controller or as the capture command. Then, an edge detector with polarity selection generates a signal (TIxFPx) ![]() The input stage samples the corresponding TIx input to generate a filtered signal TIxF. Reference: STM32 PWM input mode settings and use DMA to receive data Input capture mode ![]()
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