STLINK V3 RX/TX direction?

[Martin294]

On the STDC connector, Pin 13/14 are virtual com port signals T_VCP_RX and _TX.

Which one is input and output? They have cryptic comments like "Output for STLINK-V3SET" (for _RX) - Is RX an output and connects to the RX pin on the STM32? Or is it an input and connects to a STM32 TX output?

[Uwe Bonnes]

Have a look at https://github.com/RadioOperator/CMSIS-DAP_for_STLINK-V3MINI/blob/master/STLINK-V3MINI/Adaptor/STLINK-V3MINI_GPIOs_v4.JPG

[Tesla DeLorean]

My recollection is the "TX" on the V3 (MB1440B) side is the input, from the Target Board's USARTx_TX pin of choice.

[Martin294]

Thanks a lot! Not intuitive though. They really should make the documentation clearer (or is it just me?)!

- Martin

[Tesla DeLorean]

It's not you, the documentation is not helpful. Would help if it said T_VCP_TX (INBOUND) or something similar every time it is mentioned.

I've grown into the habit of drawing ASCII diagrams at the top-end of my main.c code illustrating connection points on board and debugger so I can remember exactly how I had it wired up when I come back to things months/years later, or I share with others.

[Piranha]

Some philosophy on connector and signal line naming. To me it seems that the most clear way is to name them so that the names answer the question "what it is on this device", not the "where the developer thinks it should be connected".