0
\$\begingroup\$

enter image description here

Edit: better quality schematic

I'm designing a PCB that includes the STM32f103C8T6 and I want to program it via SWD (with the ST-Link v2 USB connector). I'm using the Blue Pill dev board schematic (pictured above) as a reference, but it's not clear if the SWDIO and SWDCLK pins in the SWD header are directly connected to the SWIO and SWCLK pins or not. Are they?

\$\endgroup\$
  • 1
    \$\begingroup\$ You are getting answers to the question in the title of your question. However the 2nd question at the bottom of your text ("I'm really looking for is a guide or application note on how to design hardware footprints/headers (including any necessary onboard passives like pull-ups) for the common programming methods for the STM32") is completely different. It's best not to mix 2 totally different questions in one topic like that... My answer in this question links to an STM32F1 "Getting Started" document which answers most of your 2nd question. \$\endgroup\$ – SamGibson Sep 18 at 0:07
  • \$\begingroup\$ Hi Sam, thanks for the response. I'll try to limit my question scope in future - I figured since the questions are very much related that it would be kosher to ask both. Anyway, thanks for the guide, it's exactly what I'm looking for. \$\endgroup\$ – Payton Grenich Sep 18 at 0:15
  • \$\begingroup\$ Now you've seen that document, I've edited your question to remove the 2nd question and let readers focus on the original question in the title. This way there should be no further problems due to the 2nd question not matching the title. \$\endgroup\$ – SamGibson Sep 18 at 0:26
1
\$\begingroup\$

Yes, they're connected.

This schematic uses the convention that any labelled net is connected to all other nets with the same label. For example, the two nets labelled "SWDIO" and "SWCLK" on the SWD connector are connected to the pins with matching labels on the microcontroller. Similarly, the pins on the two 20-pin connectors all match up with pins on the microcontroller -- they aren't left dangling.

(There is also an error in the schematic: the pins on the microcontroller are erroneously labelled "SWIO" and "SWCLK" instead of SWDIO and SWDCLK.)

\$\endgroup\$
  • \$\begingroup\$ Hi duskwuff, thanks for the response. The names of the nets on the microcontroller don't actually match the names of the nets on the SWD header. The SWD header has "SWDIO" and "SWDCLK" while the microcontroller has "SWIO" and SWCLK" - this is the source of my confusion. \$\endgroup\$ – Payton Grenich Sep 18 at 0:07
  • \$\begingroup\$ Aha. I think that's a drafting error in the schematic, then. SWDIO = SWIO, SWDCLK = SWCLK. \$\endgroup\$ – duskwuff Sep 18 at 0:12
0
\$\begingroup\$

If this is the only page of the schematics then the SWD signals are not connected to the MCU. But this is very suspicious...why name the signals and put in a connector if there are no actual connections? I suspect that some information is missing.

\$\endgroup\$

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.