STM32H562: Immediate standby mode makes µP inaccessible

[peter7]

Hello,

 

I want to measure the power consumption of the rest of my circuit. For that, I’m putting the STM32H562 immediately to sleep. I generate a cube project and put the following in main():

int main(void)
{
    HAL_PWR_EnterSTANDBYMode();
}

 

After flashing, the current consumption suggests that it is not running, but I’m not sure. I switch the power off and on again, the current drops by 2.2mA down to 0.5mA (including the rest of the circuit).

But now, it is not possible to connect to the processor with the cube programmer. I have to do a discover first, before being able to connect to it again. MY expectation would have been that I’m directly able to flash again.

My questions are now: Why does entering the standby (or stop) mode locks the access to the device. Is this a bug or a feature? Is is documented somewhere?

 

Best regards,

Peter

 

[AScha.3]

Hi,

board ?  

st-link V..?

• look in CubeProgrammer, connect : under reset , hardware reset; + low power.
• try power down , under reset...etc.

 

 

ok then ?

 

 

[Andrew Neil]

You’ll need to connect under reset.

 

[peter7]

Hello,

 

thanks for the replies. I already tried NORMAL/HOTPLUG/UNDER RESET before without success.

But POWER DOWN is working!

 

ST-Link V2, custom board.

 

 

[Andrew Neil]

If that’s resolved the issue, please mark the solution on the post which provided the answer - not this one! 

Otherwise:

 

ST-Link V2

A real one?

 

custom board

please show schematics

[Henryjohn]

This sounds more like expected low-power/debug behavior than a hardware bug. When the STM32 enters Standby or certain Stop modes, the debug interface may become unavailable unless debug support is explicitly kept enabled. Check the STM32H562 reference manual and low-power/debug configuration in CubeMX. A reset or “connect under reset” option may also help with reflashing.