One Pulse Mode and ICP with one Input Pin

[AndersonKKK]

Hi,

What I want to implement is to receive the Input Trigger (called Ch1) signal on the rising edge in One Pulse Mode and output a PWM signal through Ch2. At the same time, I want to capture an ICP interrupt on both the rising and falling edges of Ch1 to determine whether a signal is currently being received or not on Ch1.
Previously, the STM32F103 couldn't handle the One Pulse Mode Input and ICP as a single pin, so I had to split the signal between two pins in hardware.
However, the MCUs I'm currently using are the STM32H723 and STM32G071.
I found out that they can internally route channels, so I don't need to receive signals on two pins, but can receive them with a single pin. Is this actually possible on these two MCUs?

thanks in advance.

[TDK · Accepted solution]

You can assign a pin to multiple functions, for example TIM1_CH1 and TIM2_CH2, provided those choices are available for the pin. However, if you're driving the pin with a PWM output, the IC pulses will just match that PWM output that you're sending, which doesn't seem very useful. A pin can't effectively be an input and output at the same time.

Edit: This is poorly worded. You can only assign a pin to one alternate function at a time, but you can assign it to EXTI interrupts as well. So you can't have it be TIM1_CH1 and TIM2_CH2 simultaneously, but you could do, say TIM1_CH1 and EXTI.

[waclawek.jan]

If you want to have interrupts on both rising and falling edge of the signal at TIMx_CH1 pin, while using that pin simultaneously to trigger the Slave-mode controller in the timer upon only the rising edge, and simultaneously you are occupying the capture-compare channel 2 in that timer using PWM (and don't want to move it to other channel of the same timer, 3 or 4), then - as due to that PWM on CH2 you can't use the "CH1/CH2 crossover" (as set by TIMx_CCMRx.CCxS=0b10), as @TDK explained above - probably the only option is to set up an EXTI interrupt on that TIMx_CH1 pin, to be triggered by both edges.

This btw. should be possible on the 'F1, too; however, this is notoriously impossible to be clicked in CubeMX and in Cube has to be worked around.

JW