I am working with a stm32l452rct6 microcontroller and when power is connected, the microcontroller is immediately in boot mode. St-link v2 also does not connect. What should I do?

[DPavl.11]

This is scheme for debug with swdHow to do active sw-dp with st-link v2 and stm32cubeProgrammer?

[waclawek.jan]

> when power is connected, the microcontroller is immediately in boot mode

How do you know it's in boot mode?

> St-link v2 also does not connect.

Try to connect under reset.

If you can connect through some of the bootloader protocols, check the option bytes.

JW

[DPavl.11]

I add second question. Gow to do active sw-dp with st-link v2 and stm32cubeProgrammer?

[YKMIN]

Check a SWCLK pin it should be Pull-down at Reset state about 10K value.

[Tesla DeLorean]

Check part orientation

Check VDDA/VSSA

Check BOOT0

Check NRST

​Check VTarget goes to pin 1 or 2 of ST-LINK

N​o magic options, should work out of the box unless something wrong with device.

[DPavl.11]

i don't connect only vdda and vssa, is it problem? do you know, how to solve this problem? Not connecting in my PCB, i need to rebuild PCB?

[Tesla DeLorean]

VDDA/VSSA power the PLLs and POR circuits, not just DAC/ADC

Without power, will clamp device in reset, you'll see NRST held low

Perhaps you can solder on some fine wires to test/check

[Amel NASRI]

Hi @DPavl.1​ ,

You can refer to AN4555 Getting started with STM32L4 Series and STM32L4+ Series hardware development for details about good setup mainly for power supply and debug management.

-Amel