+/** ISR to manage the reception of data from the serial port, placing received bytes into a circular buffer\r
+ *  for later transmission to the host.\r
+ */\r
+ISR(USART1_RX_vect, ISR_BLOCK)\r
+{\r
+       uint8_t ReceivedByte = UDR1;\r
+\r
+       if (USB_DeviceState == DEVICE_STATE_Configured)\r
+         Buffer_StoreElement(&Tx_Buffer, ReceivedByte);\r
+}\r
+\r