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STM32 GPIOS mode.

Muzahir Hussain
Associate III
Posted on February 03, 2018 at 18:07

In STM32 there are two modes to configure GPIOS, input and output.

In input mode we have, 

  • Analog mode
  • Floating Input
  • Input with pull-up/pull-down

In output mode,

  • General purpose output push-pull
  • General purpose output Open-drain
  • Alternate function output push-pull
  • Alternate function output Open-drain.

Can any one explain each of these configurations in detail?

Thanks!

#gpio #stm-32 #input #output
1 ACCEPTED SOLUTION

Accepted Solutions
Posted on February 04, 2018 at 01:02

These are pretty standard concepts, what's challenging your understanding here?

The 'Alternate Function' in ST's nomenclature is attached to the Peripheral's IO logic rather than a user driven GPIO

The 'Analogue Input' turns off the digital sections Schmitt Trigger input, reduces the noise

https://en.wikipedia.org/wiki/Schmitt_trigger

 

Push-Pull, a pair of transistors either drive the output high/low to the supply rails.

Open-Drain (like Open-Collector), a single transistor than can drive to ground, the high state is left floating, and can be pulled up internally or externally.

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View solution in original post

2 REPLIES 2
Posted on February 04, 2018 at 01:02

These are pretty standard concepts, what's challenging your understanding here?

The 'Alternate Function' in ST's nomenclature is attached to the Peripheral's IO logic rather than a user driven GPIO

The 'Analogue Input' turns off the digital sections Schmitt Trigger input, reduces the noise

https://en.wikipedia.org/wiki/Schmitt_trigger

 

Push-Pull, a pair of transistors either drive the output high/low to the supply rails.

Open-Drain (like Open-Collector), a single transistor than can drive to ground, the high state is left floating, and can be pulled up internally or externally.

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