SWD disabling after upload code to STM32F407VET6

Posted on February 25, 2018 at 00:21

Hi.

I wrote LED blinking code for STM32F407VET6.

When I'm using Std_Periph_driver everything is fine. But when I write just CMSIS only led blinking code, after upload hex code to 

STM32F407VET6

 code working, st-link is disconnecting and I can't upload the code again till setting boot 0 mode to ON.

What I should add to code to fix this issue?