The GPIO output before initialization

pass3master · ‎2024-12-26

We are developing a device using the STM32H743.
We are setting up the GPIO during initialization, but I am wondering about something.
What is the GPIO output before initialization? Is it high impedance?
Or does it change depending on the circuit connected to the STM32H743?

SofLit · ‎2024-12-26

Hello,

After reset it's analog input:

After reset the output is normally set to 0:

If you need to set it at a specific value on the initialization stage, set the value of the pin on ODR or BSRR register then configure the GPIO as output.

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pass3master · ‎2024-12-26

Thank you for your answer. I see, analog input!
Is it floating as an electric potential?

SofLit · ‎2024-12-27

Sorry I didn't understand your last question.

After reset it's set to Analog input and it's in high impedance state (from RM0433):

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