Dataflash_SendAddressBytes(0, CurrDFPageByte);\r
 \r
        /* Wait until endpoint is ready before continuing */\r
-       while (!(Endpoint_IsReadWriteAllowed()));\r
-\r
+       while (!(Endpoint_IsReadWriteAllowed()))\r
+       {\r
+               if (USB_DeviceState == DEVICE_STATE_Unattached)\r
+                 return;\r
+       }\r
+       \r
        while (TotalBlocks)\r
        {\r
                uint8_t BytesInBlockDiv16 = 0;\r
                                Endpoint_ClearOUT();\r
                                \r
                                /* Wait until the host has sent another packet */\r
-                               while (!(Endpoint_IsReadWriteAllowed()));\r
+                               while (!(Endpoint_IsReadWriteAllowed()))\r
+                               {\r
+                                       if (USB_DeviceState == DEVICE_STATE_Unattached)\r
+                                         return;\r
+                               }\r
                        }\r
 \r
                        /* Check if end of dataflash page reached */\r
        Dataflash_SendByte(0x00);\r
        \r
        /* Wait until endpoint is ready before continuing */\r
-       while (!(Endpoint_IsReadWriteAllowed()));\r
+       while (!(Endpoint_IsReadWriteAllowed()))\r
+       {\r
+               if (USB_DeviceState == DEVICE_STATE_Unattached)\r
+                 return;\r
+       }\r
        \r
        while (TotalBlocks)\r
        {\r
                                Endpoint_ClearIN();\r
                                \r
                                /* Wait until the endpoint is ready for more data */\r
-                               while (!(Endpoint_IsReadWriteAllowed()));\r
+                               while (!(Endpoint_IsReadWriteAllowed()))\r
+                               {\r
+                                       if (USB_DeviceState == DEVICE_STATE_Unattached)\r
+                                         return;\r
+                               }\r
                        }\r
                        \r
                        /* Check if end of dataflash page reached */\r