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STM32L412CB (48-pin device) - USART3 RX on PB11 not working

KGwer.1
Associate

I did set up a basic STM32_CubeIDE project with 3 USARTs.

When the PB11 Pin (USART3 RX) is connected to the communication signal, the signal is corrupted to a high signal level of 2.6V and a low signal level of 1.7V. This also happens also, when I configure the PB11 Pin as a General Input Pin.

The Tx Signal of USART3 on PB10 and UART1 and UART2 are working correctly.

In the Errata sheet STM32L412xx I found the following comment about PB11:

"On 48-pin devices with SMPS support, the non-bonded PB8 and PB11 GPIOs remain software configurable."

As far as I can see in the datasheet, there is no 48-pin device with SMPS support. But the "non-bonded" comment worries me a bit - does this mean, on this device the PB11 Pin is really not connected and so the USART3RX function is not working at all (not published in the errata)?

1 REPLY 1
KGwer.1
Associate

In the meantime, I found out, that an SMPS-Type of the 48-pin housing exists, and this type was on my board (SMT32L412CBT6P). This explains the behaviour...