Hello,I think you are looking for the following:HAL_SYSTICK_CLKSourceConfig(SYSTICK_CLKSOURCE_HCLK_DIV8);andHAL_SYSTICK_CLKSourceConfig(SYSTICK_CLKSOURCE_HCLK);Florian

I don' see any reason why the system should crash. I'am doing pretty much the same without experiencing any issues. The current consumption is significantly lower than just using sleep mode __wfi(); alone.If you want to change the voltage scaling as ...