Conflict from UART and STLINK

[SGian.1]

Hi there!

i start to work at one project with STM32G031J. Soo my i have this problem one of the pin is use for reset when i download the program at the same time is configurate a single wire half duplex , and 

- i can't simulate

- and it's look like every time i send out data they reset the CPU

Some one can help me

Thank you

Sergio 

[Tesla DeLorean]

Then you're going to have to make some hard choices..

Test/Debug with a different variant of the part with more pins and dead-bug that into the circuit. 

Learn to write code where you don't have to single step it all the time to understand how it executes.

Use serial output to provide telemetry and dynamic analysis of function and flow.

Perhaps you can use a NUCLEO board as a proxy until you have 95% functionality so you aren't fighting the low pin count issue beginning to end.

[BarryWhit]

Try harder to explain your question clearly. 

[Tesla DeLorean]

I suppose there's a way to change to utilization of the NRST (Pin 4), either on-the-fly, or via the Option Bytes. Cube might not do it for you, but probably coved in the Reference Manual, etc

[BarryWhit]

Interesting issue. From the datasheet:

possibly being the most opaque and least helpful footnote imaginable. "Particular care", wtf does that mean? (sigh middle-school typos in technical writing from multi-billion $$$ multi-national. can't they afford a spell-checker?)

As DeLorean foretold, the RM documents the option bytes:

So it's not enough to assign an AF to the pin in CubeMX, you also have to set the option byte to incapacitate the nRST logic.