Boundary scan testing

Thread Starter


Joined Jul 27, 2020
Hii everyone,

I'm working on Discovery board STM32F407VG soc. I know it can do 1149.1 boundary scan test. i want to test differential signal on this soc. After googling I found that differential signal can be test by 1149.6 standard. So is it possible that 1149.6 debug circuit can be on the same soc or do I need to change soc. Or to test differential signal I need to change debug adapter which supports 1149.6 boundary scan.


Joined Mar 30, 2015
Welcome to AAC!

It would be unusual for a manufacturer to not protect access to test circuitry. I worked on a microprocessor project where project management was so concerned about someone being able to hack the processor because many people on the project knew the code to enable it. I was asked to write a program that could change the code after we made the tapeout database.

We got "caught" by the FAB because they tried to risk start metal 1 and found the programming differences. Once I explained what we had done and the measures we had taken to insure that the bit swaps wouldn't cause any manufacturing issues, they let it pass.

Of the dozen or so designs I worked on, I was only asked to do that for one project.