Using SWD pins to flash code

[bhoomika_patil]

Hi,

I am using STM32H503 controller and wanted to understand if SWDIO pin can be used to flash the code.

[TDK]

Yes, the SWD connection is the typical way code is flashed using STM32CubeProgrammer and an ST-Link programmer.

[Andrew Neil · Accepted solution]

Not on its own.

The SWD interface consists of two pins:

1. SWDIO is the (bidirectional) data pin;
2. SWCLK is the clock pin.

You need both plus, of course, GND.

https://developer.arm.com/documentation/101636/0100/Debug-and-Trace/JTAG-SWD-Interface

https://learn.sparkfun.com/tutorials/arm-programming/jtag-and-swd

https://kb.segger.com/Target_Interface_SWD

Although not always strictly necessary, you should also include NRST in your debugger/programmer connection - it can get you out of some "bricked" states.

In addition, most debug/programming probes (eg, ST-Link) also want a connection to the target's VDD line.

See the documentation for your debug/programming probe.

See Application note AN5711, Getting started with STM32H5 MCU hardware development:
https://www.st.com/resource/en/application_note/an5711-getting-started-with-stm32h5-mcu-hardware-development-stmicroelectronics.pdf#page=27

[bhoomika_patil]

Thank you!

[Andrew Neil]

If that's answered your question, please mark the solution:

https://community.st.com/t5/community-guidelines/help-others-to-solve-their-issues/ta-p/575256

[Andrew Neil]

@bhoomika_patil please mark a solution in this thread.

I've moved your new question to a new thread:

https://community.st.com/t5/stm32-mcus-products/using-swd-and-usb-dfu-to-flash-code/m-p/759568#U759568