Associate II

Solved

Hi In the STM32L053R8 Datasheet, I cannot figure out the default alternative function AF0, AF1... I'm using the UART TX RX on PA10 PA9 is that the correct choice?

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Guru

AF4 is set by software.

If you used PA9/PA10 for a UART connection in your design it will be usable as such.

For the System Loader see App Note AN2606 for supported PINS and METHODS.

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ST Employee

Hello @BEKABEN ,

Correct, for UART instance 1 : PA9/PB6 -> UART1_TX and PA10/PB7 -> UART1_RX

For LPUART : PB10/PC4/PC10 -> LPUART1_TX and PC5/PC11 -> LPUART1_RX

Also, for UART instance 2 : PA2/PA14 -> UART2_TX and PA3/PA15 -> UART2_RX

Foued

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Super User

JW

Associate II

Yes

is AF4 the default setting on the stm32l053r8?

Super User

No.

Default setting of all AF is AF0 - see GPIO_AFR registers description in the GPIO chapte of Reference Manual.

JW

Associate II

If I design my schematic based on AF4 and I'm accessing the UART from PA9 PA10 is it possible to do updates in the future?

Guru

AF4 is set by software.

If you used PA9/PA10 for a UART connection in your design it will be usable as such.

For the System Loader see App Note AN2606 for supported PINS and METHODS.

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

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