AN2606 Rev 69 - STM32WBA6x: USART2 vs USART3 discrepancy in bootloader section

[bugiii]

In AN2606 Rev 69, the STM32WBA6x system bootloader section describes the UART interface as USART3, but there appear to be errors:

1. Inconsistency within the same entry:

The TX pin description mixes USART2 and USART3 in the same sentence:

USART3_TX pin Output PA12 pin: USART2 in transmission mode. Kept in reset configuration until 0x7F detected on USART_RX.

While the RX pin description correctly uses USART3:

USART3_RX pin Input PA11 pin: USART3 in reception mode. Used in alternate push-pull, pull-up mode.

2. PA11/PA12 are assigned to USART2, not USART3:

According to the STM32WBA62 datasheet, PA11 and PA12 are mapped to USART2 (USART2_RX / USART2_TX), not USART3.

Question:

Does the STM32WBA6x system bootloader actually use USART2 on PA11/PA12? It seems the document should read USART2 throughout, and the current "USART3" label is an error.

Could ST please clarify and correct this in the next revision of AN2606?

Environment:
- Document: AN2606 Rev 69
- MCU: STM32WBA62CGU6
- Section: STM32WBA6x bootloader - USART

[KDJEM.1]

Hello @bugiii ;

Thank you for bringing this issue to our attention.

I reported it internally for checking.

Internal ticket number: 226865 (This is an internal tracking number and is not accessible or usable by customers).

Thank you.

Kaouthar

[KDJEM.1 · Accepted solution]

Hello @bugiii.;

You are right, it is a typo in AN2606.

The supported USART interfaces for SM32WBA6 are USART1 and USART2.

Thank you.

Kaouthar