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jvavra
Associate III
February 2, 2023
Solved

SWD Conflict w/ USART2 or System Wake-Up on STM32L0?

  • February 2, 2023
  • 1 reply
  • 1787 views

Using CubeMX to create a new project on the STM32L0X0 series. I need two UARTS, which this part offers. However, in CubeMX, when I try to enable the SWD, it creates a conflict is the SYS tab for "System Wake-Up 3". When I roll over this, it says it conflicts with "USART2: Asynchronous Mode" . I'm not sure what System Wake-Up 3 is; I don't see any reference to multiple instances of wake-ups in the reference manual. I also don't see a GPIO conflict; the SWD interface only uses PA13 and PA14 which nothing else needs. What am I missing?

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Best answer by Jaroslav JANOS

Hi @Community member​,

the conflict in the CubeMX is caused by placing USART2_TX signal on the same pin where SYS_WKUP3 is located. So you cannot enable it because the pin is already "occupied". If you don't need this wake-up pin (I suppose you only need SWD), you can ignore it, there is no conflict with SWD and nothing should be stopping you from generating the code.

BR,

Jaroslav

1 reply

Jaroslav JANOS
Jaroslav JANOSBest answer
ST Employee
February 3, 2023

Hi @Community member​,

the conflict in the CubeMX is caused by placing USART2_TX signal on the same pin where SYS_WKUP3 is located. So you cannot enable it because the pin is already "occupied". If you don't need this wake-up pin (I suppose you only need SWD), you can ignore it, there is no conflict with SWD and nothing should be stopping you from generating the code.

BR,

Jaroslav