Differential signal test via boundary scan test

[Rsrma.1]

I want to test differential signal on STM32F407VG discovery board using boundary scan testing. I know that this soc supports boundary scan testing but is it possible to test/measure differential signal also via same way?

[Peter BENSCH]

Please don't be confused by the fact that there are JTAG pins like TMS or TCK, which are combined pins for JTAG debugging or SWD debugging only. So no, your impression is wrong, as none of the STM32 is supporting boundary scan.

Good luck!

/Peter

[Rsrma.1]

In one of the earlier question related to boundary scan a community member answered that STM32F4 is supporting boundary scan.

Please go through below link to see the whole Q&A

https://community.st.com/s/question/0D50X00009XkiFfSAJ/does-the-stm32f4-support-11491-boundary-scan-test

I also believe that they can be used for boundary scan because they have BSDL file for STM32F4, if they don't support boundary scan then why there will be a BSDL file?

[Peter BENSCH]

Sorry, my answer before was wrong, as BSDL files are available at our website and can be found by searching for BSDL.

Back to your initial question: it depends on your usage of the BSDL file, as it could be used to read the digital status of the pins or write digital data to them. So it shouldn't be possible to measure differential data, as it is usually an analog value.

Regards

/Peter

[Rsrma.1]

Yeah, In 1149.6 define that we can read differential and analog signal. So can you please tell me whether STM32F407VG support 1149.6 standard or not. Please check all the necessary documents:face_with_tears_of_joy:. and also for every standard we need to change our debugger or same debugger we can use for every standard.

[Peter BENSCH]

OK, you got me. :beaming_face_with_smiling_eyes:

But this one is correct - like all STM32 so far the STM32F407 supports 1149.1. only, as you can find in its BSDL file:

use STD_1149_1_2001.all;

attribute COMPONENT_CONFORMANCE of CortexMx: entity is "STD_1149_1_2001";

Does it answer your question? 

Regards

/Peter

[Tesla DeLorean]

What does differential mean in this context? Two GPIO inputs with opposite polarity signals applied?

Which pins?

[Rsrma.1]

Thanks peter, what I understood from your answer is that STM32F407 can't support 1149.6 standard. Please correct me if I'm wrong and suggest any controller which can support 1149.6 standard.

What does differential mean in this context? Two GPIO inputs with opposite polarity signals applied?

I'm talking about USB signals here.

[Peter BENSCH · Accepted solution]

Correct, the STM32F407 supports 1149.1 only, 1149.6 is not supported.

Until now none of the STM32 supports 1149.6 , as you can find in the BSDL files (yesterday I was double-checking all of them).

Regards

/Peter

[Rsrma.1]

Thanks for the answer Peter