-                       /** Mask for the Options parameter of the \ref USB_Init() function. This indicates that the
-                        *  USB interface should be initialized in full speed (12Mb/s) mode.
-                        */
-                       #define USB_DEVICE_OPT_FULLSPEED       (0 << 0)
+                       #if (F_USB > 6000000)
+                               /** Mask for the Options parameter of the \ref USB_Init() function. This indicates that the
+                                *  USB interface should be initialized in full speed (12Mb/s) mode.
+                                */
+                               #define USB_DEVICE_OPT_FULLSPEED   (0 << 0)
+                       #endif