-                       #if defined(USB_CAN_BE_HOST) || defined(__DOXYGEN__)\r
-                       /** Indicates the current host state machine state. When in host mode, this indicates the state\r
-                        *  via one of the values of the \ref USB_Host_States_t enum values in Host.h.\r
-                        *\r
-                        *  This value may be altered by the user application to implement the \ref HOST_STATE_Addressed,\r
-                        *  \ref HOST_STATE_Configured, \ref HOST_STATE_Ready and \ref HOST_STATE_Suspended states which\r
-                        *  are not implemented by the library.\r
-                        *\r
-                        *  \note This global is only present if the user application can be a USB host.\r
-                        *\r
-                        *  \ingroup Group_Host\r
-                        */\r
-                       extern volatile uint8_t USB_HostState;\r
+                       #if defined(USB_CAN_BE_DEVICE) || defined(__DOXYGEN__)\r
+                               #if !defined(DEVICE_STATE_AS_GPIOR) || defined(__DOXYGEN__)\r
+                                       /** Indicates the current device state machine state. When in device mode, this indicates the state\r
+                                        *  via one of the values of the \ref USB_Device_States_t enum values.\r
+                                        *\r
+                                        *  This value should not be altered by the user application as it is handled automatically by the\r
+                                        *  library. The only exception to this rule is if the NO_LIMITED_CONTROLLER_CONNECT token is used\r
+                                        *  (see \ref EVENT_USB_Connect() and \ref EVENT_USB_Disconnect() events).\r
+                                        *\r
+                                        *  To reduce program size and speed up checks of this global, it can be placed into one of the AVR's\r
+                                        *  GPIOR hardware registers instead of RAM by defining the DEVICE_STATE_AS_GPIOR token to a value \r
+                                        *  between 0 and 2 in the project makefile and passing it to the compiler via the -D switch. When\r
+                                        *  defined, the corresponding GPIOR register should not be used in the user application except\r
+                                        *  implicitly via the library APIs.\r
+                                        *\r
+                                        *  \note This global is only present if the user application can be a USB device.\r
+                                        *\r
+                                        *  \note This variable should be treated as read-only in the user application, and never manually\r
+                                        *        changed in value except in the circumstances outlined above.\r
+                                        *\r
+                                        *  \see \ref USB_Device_States_t for a list of possible device states\r
+                                        *\r
+                                        *  \ingroup Group_Device\r
+                                        */\r
+                                       extern volatile uint8_t USB_DeviceState;\r
+                               #else\r
+                                       #define _GET_DEVICE_GPIOR_NAME2(y) GPIOR ## y\r
+                                       #define _GET_DEVICE_GPIOR_NAME(x)  _GET_DEVICE_GPIOR_NAME2(x)\r
+                                       #define USB_DeviceState _GET_DEVICE_GPIOR_NAME(DEVICE_STATE_AS_GPIOR)\r
+                               #endif\r