I want to use ST-Link as a debugger and seri port reader. Any one know about it? Please help me.

[Tesla DeLorean]

The question here is really poorly framed. Some context?

The stand-alone ST-LINK/V2 doesn't have a serial port (VCP)

The on-board ST-LINK/V2-1 and assorted ST-LINK/V3 do have a serial port.

The boot loader protocol and usage for STM32 are covered in app notes AN3155 and AN2606 as I recall.

Perhaps review these, and provide some more details about what it is you're trying to do, and what you've tried or experimented with so far.

[AElma.1]

Actually, I just want to make my own programmer circuit for STM32G474RET6 MCU.

Problem: I do not want to just programming and debugging like ST-Link. I want to read data from serial port too. But ST-link doesn't have any RX/TX pins for that.

Any idea for this programming circuit? Really apriciated.

[AElma.1]

I mean programming STM32G474 from programming circuits. Programming circuit could be has a STM32F103.

[Tesla DeLorean]

>>Problem: I do not want to just programming and debugging like ST-Link.

So which is it?

Do you, or don't you want to use SWD/JTAG methods?

Do you want to use the System Boot Loader, per AN3155, ie serial protocol?

You want to just use a serial connection? So a SiLabs or FTDI USB to CMOS Serial chip would suffice? Or implement a VCP/CDC USB Device on an STM32

You want some other chip to program? Here's an example of an ATMEL/MICROCHIP MCU programming an STM32L0 in a Murata LoRa module, using the methods outlined in AN3155

https://github.com/arduino-libraries/MKRWAN/blob/master/examples/MKRWANFWUpdate_standalone/MKRWANFWUpdate_standalone.ino

[KnarfB]

STLINK-V3MODS and STLINK-V3MINI do have a VCP, see UM2502 User manual - STMicroelectronics

hth

KnarfB

[AElma.1]

Thank you so much for advice I will work on it.