after few times programming debugger can't recognize microcontroller(stm32f101vbt6)

[Dwalk.11]

hi

I'm using stm32f101vbt6 by st-linkv2 programmer.

after few times programming my micro i get this message : no target connected. so my debugger can't recognize microcontroller.

i checked every connection and it was ok I tried j-link programmer but j-link couldn't recognize micro too. so i changed micro and programmed micro few times and this problem happend again for three times.

in my pcb design i connect SWDIO from programmer to micro and between them i put 330 ohm resistor.same thing for SWCLK as the picture uploaded.

in my board when programming i'm connect my power plug on from adapter

i don't know why this happening.is it because of ESD(Electrostatic Discharge)?Is my design has any problems?

i didn't have this problem for stm32f103.

appreciate your help.

[Ozone]

> i don't know why this happening.is it because of ESD(Electrostatic Discharge)?Is my design has any problems?

Might be.

> after few times programming my micro i get this message 

But this sounds like the boards work in general, and the connection is correct.

I suppose your firmware causes trouble, perhaps a lockup or sleep mode.

Try to boot into system mode and do a mass erase.

I think the Cubeprogrammer is the recent ST application for the job.

The proper boot pin combination for your MCU should be descrided in the reference manual and/or datasheet.