How STM32G0Bxx PA11/PA12 pad remap to PA9/PA10 works and for what is useful for?

[yo3hcv]

Hello,

Reading the datasheet, pads PA11 and PA12 can be remapped to PA9/PA10.

I don't understand how this remapping works.

Variant A

-------------

This is a full swap, meaning that pads PA9/10 will exchange with PA11/12 ?

Variant B

-------------

Pads PA11/12 will be PA9/10.. having 2 pads for PA9 and 2 for PA10 ?

Variant C

------------

Pads PA11/12 will be PA9/10... but older PA9/PA10 will be not connected ?!?

What is this useful for?

Becoming PA9/PA10 means that just having other PAD locations at package, but functions stays the same and belongs to PA9/10.

Thanks for clarifications

[gbm]

Variant A: PA9/10 replace PA11/12

Application: see the PA9/10 and PA11/12 functions. For example, depending on the particular design you may need UART on PA9/10 or USB on PA11/12.

[waclawek.jan]

It's useful only on the pin-constrained packages, not on packages where all PA9..12 are present.

JW