Can you change SWO output to a different GPIO? I want to use the SPI that conflicts with the SWO, but still need to printf on SWO.

[Matt Roybal]

Posted on January 29, 2018 at 21:09

Hello, I am using STM32F103 and STM32F301. I need to use the SPI that shares the same pin as SWO. Is it possible to move the SWO to a different pin so I can retain the printf to console functionality for debugging?

[Tesla DeLorean]

Posted on January 29, 2018 at 21:29

Only PB3 supported. Use a USART_TX as an alternative. 

[Matt Roybal]

Posted on January 29, 2018 at 22:29

Hi Clive, thanks for the info! So I just need to chose a group of pins, such as RX1/TX1, TX2/TX2, RX3/TX3 and get a UART protocol running on those pairs?

[Andrew Neil]

Posted on January 30, 2018 at 10:47

SWO =

S

erial

W

ire

O

utput - as the name suggests, it is output (Tx) only.

http://infocenter.arm.com/help/topic/com.arm.doc.ddi0314h/Chdhgebe.html

 

So there would be no need to reserve an Rx pin for equivalent funcitonality

[T J]

Posted on January 29, 2018 at 23:58

In the cube, you can hold <cntl> and click the pin to see alternatives, for the SPI port, I mean...

[T J]

Posted on January 30, 2018 at 07:10

You use the cube software, to see the available pins for your requirements.

Did you use the cube before ?

Edit:

before the cube there is the reference material;

PM0214   STM32F3 and STM32F4 Series Cortex®-M4 programming manual.

Also, in the processor data sheet

look for PA9  in the alternate function pin map.

here you can see all the variations of all the pins.