cancel
Showing results for 
Search instead for 
Did you mean: 

Where can I find documentation on the I/Os that are not floating during and after reset?

TAcha.1
Associate

I am using STM32H745ZI for a personal project. Page 60 of the attached datasheet from ST says there are I/Os that are floating unless otherwise specified. I want to use an I/O that I can guarantee will be in either low or high state on a reset or if the processor stops working.

My goal is to find an I/O that I can be certain will be in a particular state (high or low) at reset or if the processor is not working but has power.

Any help is appreciated.

1 ACCEPTED SOLUTION

Accepted Solutions

The Reference Manual would show the initial state of the GPIO registers.

NRST has a pull-up, clamped to zero if POR for VDDA below threshold

Tips, Buy me a coffee, or three.. PayPal Venmo
Up vote any posts that you find helpful, it shows what's working..

View solution in original post

3 REPLIES 3

The Reference Manual would show the initial state of the GPIO registers.

NRST has a pull-up, clamped to zero if POR for VDDA below threshold

Tips, Buy me a coffee, or three.. PayPal Venmo
Up vote any posts that you find helpful, it shows what's working..
TAcha.1
Associate

Thanks for replying Tesla.

I have perused through the reference Manual but the notes section has no information on the initial state of the GPIO's that are non floating.

Hi @TAcha.1​ ,

Look to the reset values of GPIO registers in the reference manual (RM0399) to get the exact answer. Here an example:0693W000008wWopQAE.png 

Pins used for debug purpose are the ones where there is an exception:

0693W000008wWnDQAU.png-Amel

To give better visibility on the answered topics, please click on Accept as Solution on the reply which solved your issue or answered your question.