STM32H750XBH6 Unused pins = Unconnected pins. Is it ok to only leave them floating? I prefer to not to connect them to GND ?

[Tesla DeLorean]

Yes

If configured as analogue inputs the schmitt trigger digital input buffer is disconnected, so it shouldn't oscillate

[FBL]

Hi @Björn Erik Hellerstedt​,

As mentioned by @Community member​, you can find AN4899 in section 7 in that unused pins should be configured as analog input as it reduces power consumption. Also, in section 6, it is recommended to avoid floating unused pins. You should either connect them to ground or to VDD.

[Nikita91]

Hi @F.Belaid​ ,

I read the AN4899 (rev3 mar 2022), and it mentions the register GPIOx_ASCR in multiple places.

What is this register? I cant found it in RM of F1, F4, G4, H7.

It is not mentioned in the section 2.2 Register abbreviations.

[FBL]

Hello @Nikita91​, 

First, GPIOx_ASCR register is specific to some series. For example, you can find it in L4 Reference Manual section 8.5.12. This register is used to configure the analog connection of the IOs to the ADC input.

Second, AN4899 note is applicable to all ST MCUs.

[waclawek.jan · Accepted solution]

AFAIK, GPIOx_ASCR is only in the 'L47x/'L48x. so not even in all 'L4.

JW

[Nikita91]

Thanks, I learned something.

In fact, this concerns more the use of analog devices than the configuration of GPIO, and this may be why the application note does not talk about it much.

[FBL]

Indeed @Community member​. Thanks for the clarification.

Please @Björn Erik Hellerstedt​ if your question is answered, please close this topic by choosing Select as Best.