VREGEN:1 – voltage regulator enabler (Vusb), UTRDIS:0 – disable internal reciever, UPUDIS:0 – disable internal regulator, USBEN:1  (enables usb. Resets pingponbuffer PPBI, activates internal voltageregulator if VREGEN=1), FSEN:1 – full speed enable), UIE (usb interrupt enable bits), USBIE:1 – usbinterrupt enable.