is this and example of STM32G0 core lockup during a software reset?

[Tom MacDonald]

Using a STM32G0F06

I have a bootloader/application that I am debugging. I am facing a strange problem. Often, I command the app to drop to bootloader (via a software reset). When I execute the software reset code, occasionally the core locks up.

Here is a video showing the core registers and the disassembly as I step debug through the reset code:

https://youtu.be/8SxjNWpSIss

A couple of questions:

• Is this a MCU core lockup?
  • If not, what is it?
• Does the PC go to 0x1FFF19A6 during a core lockup, or is that just random?
• How come the IWDG I have configured does not reset the MCU after it has locked up? Does it get locked up to?
• Is there some way I can programmatically recover from a core lockup:
  • MCU pulls its' own external reset pin low?

[gbm]

It's either the application was not flashed or unstable BOOT0 input - the bootloader is invoked instead of your application

[Tom MacDonald]

The problem is that I have the option bytes configured to not care about the BOOT0 input (see screenshot below). From my research it seems like this should be impossible?

[Tom MacDonald · Accepted solution]

Actually, I just figured out why this behaviour was occurring. This is from the STM32G030F6 device errata sheet:

 

I fixed it by:

• Flashing the app I wanted to debug
• disconnecting the debugger
• power cycling the pcba
• connecting the debugger (after app had already launched)
• now I can reset/reflash etc. as expected