GPIO after reset value

[User16400061767647298503]

Hi everyone,

First of all thanks for your answers and sorry for my english level.

I checked the reference manual of my MCU (RM0468) and I realized that the after reset value of the most GPIO is high impedance.

I need to stablish a new after reset value in some of GPIOs because I am controlling some mosfets and sometimes they switch with the MCU reset. I have tried to configure the pull-down resistor of the GPIOs but my problem is still happening because my code takes some time to execute.

My question is: How can I stablish a new after reset value of a GPIO? I have read that there are a locking system but I dont understand how it works. Any Idea?

Thank you very much

[Andrei Chichak]

External pull-up/pull-down resistors.

The GPIO pins reset to inputs and there is always a time between power up and programming the GPIO pins as outputs in a particular state. You'll have to use external resistors to bridge this startup time.

[User16400061767647298503]

It doesnt work.

GPIOs sometimes start with 3V3 and sometimes with 0V. High impedance is unpredictable. The pull-up and pull-down external resistors doesnt work because I can use, for example, a pull-down resistor, but the GPIO start with 3V3 and my mosfet switch after reset.

[Piranha]

You are misunderstanding the basics of electronics. High impedance doesn't push or pull any significant current and therefore will not force the pin to any specific level.

[S.Ma]

Some specifc pins have permanent pull up/down such as JTAG pins, here might be handy....