Hello, I am new here and I am getting stuck with STM32's USB features. I tried the VirtualCOMPort_Loopback example from USB-FS Library and successfully got it running on STM32F103C8 development board. But it seems that the MCU is not running unless the USB state is CONFIGURED. I've tried fiddling with the suspend function in usb_power.c. I could get it running without USB being in configured state on the first time it booted. But then after I plugged the USB in, got it configured, and then unplugged the USB, the MCU was not running anymore. It will only run without USB on the first time it boots. What I want to achieve is making the USB Virtual COMPort as a side-feature. I don't want it as the main program. Please help me how to do this.