USART receive break and reset mcu

[tvill.1]

Hello,

I use STM32G0 and USART2 in IT mode or DMA mode.

When the mcu receive a break command on uart line, he reset after entering on the IRQ handler.

Have you an idea ?

Regards

[tvill.1]

I add the report from cube MX and caal stack after the reset in irq handler.

[waclawek.jan]

How do you know it's BREAK which makes the mcu to reset?

Normal data Rx works OK?

If you run code which does not handle UART (e.g. a simple LED blinky), does it reset upon receiving BREAK? (this is aimed at possible hardware problem)

Try to find where BREAK is handled in the HAL handler and place a breakpoint there.

Read out and check/compare-to-working/post UART registers content.

JW

[tvill.1]

Hi @Community member​ , i have tested yout proposition with simple led blinky and i have the reset on my STM32G0B0 (with uart2 disable).

The break is handle nowhere, it's my problem and the origin of my idea about design mistake.

[tvill.1]

Other thing, my STM32G0B0 is recognized as G0B1 (mcu sourced directly from ST) on the stlink tool.

I have soldered this mcu on nucleo32-G031K8 for my prototype and already integrated on my final design.

[waclawek.jan]

OK so is it a hardware problem? If yes, is it related to the Nucleo itself, or your "integration"?

Which pin are we talking about exactly?

JW

[tvill.1]

it's directly the mcu design.

I use de default USART2 pin (PA2-PA3)

I have tested with USART4 and all works fine.

I think we have a real problem with this mcu G0B0 and USART2

[waclawek.jan]

@tvill.1​ ,

And what do you have connected to PA3? How exactly are you generating the BREAK? At what baudrate?

On the Nucleo boards, PA2/PA3 is connected to the on-board STLink, through solder bridges - did you disconnect these solder bridges?

JW

[Andrew Neil]

Maybe the ST-Link could be mis-handling the break, and causing a reset ... ?

(the St-Link has control of the reset line)

[tvill.1]

i have not stlink on my custom designe pcb and i have still the reset.