What is "Serial Wire" for under SYS

[Carl_G]

In STM32CubeIDE in the SYS tab there is a checkbox called "Serial Wire". When I check it, it highlights the two ports used for serial wire debugging. But that's all it seems to do. Is this just a helper to let me know where the debug pins are?

[Andrew Neil]

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@Carl_G wrote:

In STM32CubeIDE in the SYS tab 

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You mean in the Device Configuration view?

Here:

What IDE version are you using, and what chip?

https://community.st.com/t5/community-guidelines/how-to-write-your-question-to-maximize-your-chances-to-find-a/ta-p/575228

[Uwe Bonnes]

If it is SWD, it is the debug access.

[Carl_G]

Yes, thats the place. I have STM32G071. It doesn't have SWV. I thought it was for that at first. My IDE is 1.16.1

[Ozone]

>  I have STM32G071. It doesn't have SWV.

Oh yes, it does.
This is the debug interface, a reduced variant of JTAG.
The respective pins have SWD functionality by default after reset, you would need to reconfigure them at startup to change that.

[Andrew Neil]

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@Carl_G wrote:

I have STM32G071. It doesn't have SWV. I thought it was for that at first. My IDE is 1.16.1

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swv = Serial Wire Viewer:

https://developer.arm.com/documentation/ddi0314/h/Serial-Wire-Viewer/About-the-Serial-Wire-Viewer 

The STM32G071 has SWD - Serial Wire Debug - as its programming & debug interface:

But, indeed, no SWO for use with the Serial Wire Viewer.

[Carl_G]

But SWD works without this setting. And it doesn't seem to change the source at all. Does this enable attach while running or something?

I don't see any SWO on this mcu so it can't have SWV right? This is Cortex M0+ I believe.

[Pavel A. · Accepted solution]

Yes basically SWD pins are marked in the Cube to let you know where are the debug pins (and avoid touching them in the program). The debugger configures them automatically.

> I don't see any SWO on this mcu so it can't have SWV right? This is Cortex M0+ I believe.

Yes. It is M0+ and it does not have SWO.