STLink emulator with Stop mode condition

[davide_mp]

Hi everyone,
I have a problem, let's see if someone can help me...
I have a board that works with an STM32L053xxxx, my application, at a certain point, enters stop mode. Here comes the problem, the emulator disconnects.
Is there any technique or emulator that allows me to continue the emulation even in stop mode?

 

[Andrew Neil]

See section 33.9.1 in the Reference Manual:

Also, if you're using STM32CubeIDE, enable debug in low-power:

 

And make sure that your application doesn't disable the SWD pins during sleep ...

[davide_mp]

HI,
Thanks for your reply, now I know it's somehow possible.
I could still use your help, please.
I use Keil uVision 5 and an STM32L053C8T6.
It's not like you know how to set up the debugger, at the moment I use a simple ST-Link Debugger V.1.
I don't understand if it is possible to program this to work or I have to use other debuggers.

Greetings,

David

[Andrew Neil]

I can't even visualise what an ST-Link V1 looked like!

How old is it?

The features mentioned in section 33.9.1 of the Reference Manual are internal to the chip - so shouldn't be restricted by what debug probe you use ...

You'd have to ask Keil what is their equivalent of the  STM32CubeIDE's "enable debug in low-power" feature:

https://community.arm.com/support-forums/f/keil-forum

 

[Andrew Neil]

On higher Cortex-Ms, there's a bit you can directly test to see if a debugger is active.

That's not available on Cortex-M0/M0+, but you can still infer it from the DBGMCU Clock Enable:

	 // Look at the DBGMCU Clock Enable:
	 // This is 1 if a debug session is active, 0 if not.
	 // (It *is* still 0 when a debugger is physically connected,
	 // but not in a debug session)
	 if( RCC->APB2ENR & RCC_APB2ENR_DBGMCUEN )
	 {
		 fprintf( stderr, "Debugger Connected\n" );

		 // Allow debug in STOP
		 DBGMCU->CR |= DBGMCU_CR_DBG_STOP;
	 }
	 else
	 {
		 // No debugger connected.
		 :
		 :
	 }