procedure interrupt; begin USB_Interrupt; // USB_MSD processing procedure end;The USB initialization procedure ("InitUsb") takes care of the enabling of the necessary interrupts.
InitUsb; // Init USB_MSD and start the enumeration process repeat until ConfiguredUsb; // wait for the completion of the USB enumerationAs you can see, the initialisation of USB_MSD and starting up of the USB enumeration procedure is done with a call to "InitUsb". This procedure does not wait for the USB enumeration process to complete.