// GPIO setup.
	LOCAL_EXP(GPIO,USB_PORT)->CFGLR = (
#ifdef BOOTLOADER_KEEP_PORT_CFG
		LOCAL_EXP(GPIO,USB_PORT)->CFGLR 
#else
		0x44444444 // reset value (all input)
#endif
		// Reset the USB Pins
		& ~( 0xF<<(4*USB_PIN_DP) | 0xF<<(4*USB_PIN_DM) 
		#if defined(USB_PIN_DPU) && (PORTID_EQUALS(USB_DPU_PORT,USB_PORT) || !defined(USB_DPU_PORT))
			| 0xF<<(4*USB_PIN_DPU)
		#endif
		// reset Bootloader Btn Pin
		#if defined(BOOTLOADER_BTN_PORT) && PORTID_EQUALS(BOOTLOADER_BTN_PORT,USB_PORT)
			| 0xF<<(4*BOOTLOADER_BTN_PIN)
		#endif
		)
	) |
	// Configure the USB Pins
#ifdef USB_PIN_DPU
		(GPIO_Speed_50MHz | GPIO_CNF_OUT_PP)<<(4*USB_PIN_DPU) |
#endif
#if defined(BOOTLOADER_BTN_PORT) && PORTID_EQUALS(BOOTLOADER_BTN_PORT,USB_PORT)
	#if defined(BOOTLOADER_BTN_PULL)
		(GPIO_Speed_In | GPIO_CNF_IN_PUPD)<<(4*BOOTLOADER_BTN_PIN) | 
	#else
		(GPIO_Speed_In | GPIO_CNF_IN_FLOATING)<<(4*BOOTLOADER_BTN_PIN) | 
	#endif
#endif
		(GPIO_Speed_In | GPIO_CNF_IN_PUPD)<<(4*USB_PIN_DP) | 
		(GPIO_Speed_In | GPIO_CNF_IN_PUPD)<<(4*USB_PIN_DM);