I am using stm32l071cbt6

I research and find out NVIC_CoreReset function but ı guess M0 cortex does not support this property.

I want to reset system but only software. I dont want to reset hardware. For instance B9 pin must be set always. But when ı use NVIV_SystemReset function, B9 pin goes low 200 ms even if ı set it in MX_GPIO_Init() function.

Check 3.3 volt that come to microprocessor.

Hımove your project file to orijinal workspace folder