Added new USB_DeviceState variable to keep track of the current Device mode USB state.

Added new Endpoint_ClearStatusStage() convenience function to assist with the status stages of control transfers.

Removed vague USB_IsConnected global - test USB_DeviceState or USB_HostState explicitly to gain previous functionality.

Removed USB_IsSuspended global - test USB_DeviceState against DEVICE_STATE_Suspended instead.

Fixed possible enumeration errors from spinloops which may fail to exit if the USB connection is severed before the exit condition becomes true.

Demos/Device/LowLevel/AudioInput/AudioInput.c

@@ -139,9 +139,7 @@ void EVENT_USB_UnhandledControlPacket(void)
 				/* Check if the host is enabling the audio interface (setting AlternateSetting to 1) */
 				StreamingAudioInterfaceSelected = ((USB_ControlRequest.wValue) != 0);
 				
-				/* Acknowledge status stage */
-				while (!(Endpoint_IsINReady()));
-				Endpoint_ClearIN();
+				Endpoint_ClearStatusStage();
 			}
 
 			break;
@@ -152,7 +150,7 @@ void EVENT_USB_UnhandledControlPacket(void)
 void USB_Audio_Task(void)
 {
 	/* Device must be connected and configured for the task to run */
-	if (!(USB_IsConnected) || !(USB_ConfigurationNumber))
+	if (USB_DeviceState != DEVICE_STATE_Configured)
 	  return;
 
 	/* Check to see if the streaming interface is selected, if not the host is not receiving audio */

Demos/Device/LowLevel/AudioOutput/AudioOutput.c

@@ -166,9 +166,7 @@ void EVENT_USB_UnhandledControlPacket(void)
 				/* Check if the host is enabling the audio interface (setting AlternateSetting to 1) */
 				StreamingAudioInterfaceSelected = ((USB_ControlRequest.wValue) != 0);
 				
-				/* Acknowledge status stage */
-				while (!(Endpoint_IsINReady()));
-				Endpoint_ClearIN();
+				Endpoint_ClearStatusStage();
 			}
 
 			break;
@@ -181,7 +179,7 @@ void EVENT_USB_UnhandledControlPacket(void)
 void USB_Audio_Task(void)
 {
 	/* Device must be connected and configured for the task to run */
-	if (!(USB_IsConnected) || !(USB_ConfigurationNumber))
+	if (USB_DeviceState != DEVICE_STATE_Configured)
 	  return;
 
 	/* Check to see if the streaming interface is selected, if not the host is not receiving audio */

Demos/Device/LowLevel/CDC/CDC.c

@@ -56,12 +56,15 @@ CDC_Line_Coding_t LineCoding = { .BaudRateBPS = 9600,
  */
 	
 static int CDC_putchar (char c, FILE *stream)
-{
-	if (!(USB_IsConnected))
-	  return -1;
-	  
+{	  
 	Endpoint_SelectEndpoint(CDC_TX_EPNUM);
-	while (!(Endpoint_IsReadWriteAllowed()));
+
+	while (!(Endpoint_IsReadWriteAllowed()))
+	{
+		if (USB_DeviceState != DEVICE_STATE_Configured)
+		  return -1;
+	}
+
 	Endpoint_Write_Byte(c);
 	Endpoint_ClearIN();
 	
@@ -76,10 +79,11 @@ static int CDC_getchar (FILE *stream)
 	
 	for (;;)
 	{
-		if (!(USB_IsConnected))
-		  return -1;
-
-		while (!(Endpoint_IsReadWriteAllowed()));
+		while (!(Endpoint_IsReadWriteAllowed()))
+		{
+			if (USB_DeviceState != DEVICE_STATE_Configured)
+			  return -1;
+		}
 	
 		if (!(Endpoint_BytesInEndpoint()))
 		{
@@ -229,9 +233,7 @@ void EVENT_USB_UnhandledControlPacket(void)
 						 CONTROL_LINE_OUT_* masks to determine the RTS and DTR line states using the following code:
 				*/
 				
-				/* Acknowledge status stage */
-				while (!(Endpoint_IsINReady()));
-				Endpoint_ClearIN();
+				Endpoint_ClearStatusStage();
 			}
 	
 			break;
@@ -244,18 +246,17 @@ void CDC_Task(void)
 	char*       ReportString    = NULL;
 	uint8_t     JoyStatus_LCL   = Joystick_GetStatus();
 	static bool ActionSent      = false;
-
-	char* JoystickStrings[] =
-		{
-			"Joystick Up\r\n",
-			"Joystick Down\r\n",
-			"Joystick Left\r\n",
-			"Joystick Right\r\n",
-			"Joystick Pressed\r\n",
-		};
+	char*       JoystickStrings[] =
+					{
+						"Joystick Up\r\n",
+						"Joystick Down\r\n",
+						"Joystick Left\r\n",
+						"Joystick Right\r\n",
+						"Joystick Pressed\r\n",
+					};
 	
 	/* Device must be connected and configured for the task to run */
-	if (!(USB_IsConnected) || !(USB_ConfigurationNumber))
+	if (USB_DeviceState != DEVICE_STATE_Configured)
 	  return;
 	  
 #if 0
@@ -319,7 +320,11 @@ void CDC_Task(void)
 		if (IsFull)
 		{
 			/* Wait until the endpoint is ready for another packet */
-			while (!(Endpoint_IsINReady()));
+			while (!(Endpoint_IsINReady()))
+			{
+				if (USB_DeviceState == DEVICE_STATE_Unattached)
+				  return;
+			}
 			
 			/* Send an empty packet to ensure that the host does not buffer data sent to it */
 			Endpoint_ClearIN();

Demos/Device/LowLevel/DualCDC/DualCDC.c

@@ -211,9 +211,7 @@ void EVENT_USB_UnhandledControlPacket(void)
 				/* Acknowledge the SETUP packet, ready for data transfer */
 				Endpoint_ClearSETUP();
 				
-				/* Acknowledge status stage */
-				while (!(Endpoint_IsINReady()));
-				Endpoint_ClearIN();
+				Endpoint_ClearStatusStage();
 			}
 	
 			break;
@@ -228,20 +226,19 @@ void CDC1_Task(void)
 	char*       ReportString    = NULL;
 	uint8_t     JoyStatus_LCL   = Joystick_GetStatus();
 	static bool ActionSent      = false;
-
+	char*       JoystickStrings[] =
+					{
+						"Joystick Up\r\n",
+						"Joystick Down\r\n",
+						"Joystick Left\r\n",
+						"Joystick Right\r\n",
+						"Joystick Pressed\r\n",
+					};
+	
 	/* Device must be connected and configured for the task to run */
-	if (!(USB_IsConnected) || !(USB_ConfigurationNumber))
+	if (USB_DeviceState != DEVICE_STATE_Configured)
 	  return;
 
-	char* JoystickStrings[] =
-		{
-			"Joystick Up\r\n",
-			"Joystick Down\r\n",
-			"Joystick Left\r\n",
-			"Joystick Right\r\n",
-			"Joystick Pressed\r\n",
-		};
-
 	/* Determine if a joystick action has occurred */
 	if (JoyStatus_LCL & JOY_UP)
 	  ReportString = JoystickStrings[0];
@@ -273,7 +270,11 @@ void CDC1_Task(void)
 		Endpoint_ClearIN();
 
 		/* Wait until the endpoint is ready for another packet */
-		while (!(Endpoint_IsINReady()));
+		while (!(Endpoint_IsINReady()))
+		{
+			if (USB_DeviceState == DEVICE_STATE_Unattached)
+			  return;
+		}
 		
 		/* Send an empty packet to ensure that the host does not buffer data sent to it */
 		Endpoint_ClearIN();
@@ -293,7 +294,7 @@ void CDC1_Task(void)
 void CDC2_Task(void)
 {
 	/* Device must be connected and configured for the task to run */
-	if (!(USB_IsConnected) || !(USB_ConfigurationNumber))
+	if (USB_DeviceState != DEVICE_STATE_Configured)
 	  return;
 
 	/* Select the Serial Rx Endpoint */
@@ -324,7 +325,11 @@ void CDC2_Task(void)
 		Endpoint_ClearIN();
 
 		/* Wait until the endpoint is ready for the next packet */
-		while (!(Endpoint_IsINReady()));
+		while (!(Endpoint_IsINReady()))
+		{
+			if (USB_DeviceState == DEVICE_STATE_Unattached)
+			  return;
+		}
 
 		/* Send an empty packet to prevent host buffering */
 		Endpoint_ClearIN();

Demos/Device/LowLevel/GenericHID/GenericHID.c

@@ -148,7 +148,11 @@ void EVENT_USB_UnhandledControlPacket(void)
 				Endpoint_ClearSETUP();
 				
 				/* Wait until the generic report has been sent by the host */
-				while (!(Endpoint_IsOUTReceived()));
+				while (!(Endpoint_IsOUTReceived()))
+				{
+					if (USB_DeviceState == DEVICE_STATE_Unattached)
+					  return;
+				}
 
 				Endpoint_Read_Control_Stream_LE(&GenericData, sizeof(GenericData));
 
@@ -158,7 +162,11 @@ void EVENT_USB_UnhandledControlPacket(void)
 				Endpoint_ClearOUT();
 
 				/* Wait until the host is ready to receive the request confirmation */
-				while (!(Endpoint_IsINReady()));
+				while (!(Endpoint_IsINReady()))
+				{
+					if (USB_DeviceState == DEVICE_STATE_Unattached)
+					  return;
+				}
 				
 				/* Handshake the request by sending an empty IN packet */
 				Endpoint_ClearIN();
@@ -203,7 +211,7 @@ void CreateGenericHIDReport(uint8_t* DataArray)
 void HID_Task(void)
 {
 	/* Device must be connected and configured for the task to run */
-	if (!(USB_IsConnected) || !(USB_ConfigurationNumber))
+	if (USB_DeviceState != DEVICE_STATE_Configured)
 	  return;
 
 	Endpoint_SelectEndpoint(GENERIC_OUT_EPNUM);

Demos/Device/LowLevel/Joystick/Joystick.c

@@ -182,7 +182,7 @@ bool GetNextReport(USB_JoystickReport_Data_t* ReportData)
 void HID_Task(void)
 {
 	/* Device must be connected and configured for the task to run */
-	if (!(USB_IsConnected) || !(USB_ConfigurationNumber))
+	if (USB_DeviceState != DEVICE_STATE_Configured)
 	  return;
   
 	/* Select the Joystick Report Endpoint */

Demos/Device/LowLevel/Keyboard/Keyboard.c

@@ -172,7 +172,11 @@ void EVENT_USB_UnhandledControlPacket(void)
 				Endpoint_ClearSETUP();
 				
 				/* Wait until the LED report has been sent by the host */
-				while (!(Endpoint_IsOUTReceived()));
+				while (!(Endpoint_IsOUTReceived()))
+				{
+					if (USB_DeviceState == DEVICE_STATE_Unattached)
+					  return;
+				}
 
 				/* Read in the LED report from the host */
 				uint8_t LEDStatus = Endpoint_Read_Byte();
@@ -183,9 +187,7 @@ void EVENT_USB_UnhandledControlPacket(void)
 				/* Clear the endpoint data */
 				Endpoint_ClearOUT();
 
-				/* Acknowledge status stage */
-				while (!(Endpoint_IsINReady()));
-				Endpoint_ClearIN();
+				Endpoint_ClearStatusStage();
 			}
 			
 			break;
@@ -200,9 +202,7 @@ void EVENT_USB_UnhandledControlPacket(void)
 				/* Send the flag to the host */
 				Endpoint_ClearIN();
 
-				/* Acknowledge status stage */
-				while (!(Endpoint_IsOUTReceived()));
-				Endpoint_ClearOUT();
+				Endpoint_ClearStatusStage();
 			}
 			
 			break;
@@ -214,9 +214,7 @@ void EVENT_USB_UnhandledControlPacket(void)
 				/* Set or clear the flag depending on what the host indicates that the current Protocol should be */
 				UsingReportProtocol = (USB_ControlRequest.wValue != 0);
 
-				/* Acknowledge status stage */
-				while (!(Endpoint_IsINReady()));
-				Endpoint_ClearIN();
+				Endpoint_ClearStatusStage();
 			}
 			
 			break;
@@ -228,9 +226,7 @@ void EVENT_USB_UnhandledControlPacket(void)
 				/* Get idle period in MSB, IdleCount must be multiplied by 4 to get number of milliseconds */
 				IdleCount = ((USB_ControlRequest.wValue & 0xFF00) >> 6);
 				
-				/* Acknowledge status stage */
-				while (!(Endpoint_IsINReady()));
-				Endpoint_ClearIN();
+				Endpoint_ClearStatusStage();
 			}
 			
 			break;
@@ -245,9 +241,7 @@ void EVENT_USB_UnhandledControlPacket(void)
 				/* Send the flag to the host */
 				Endpoint_ClearIN();
 
-				/* Acknowledge status stage */
-				while (!(Endpoint_IsOUTReceived()));
-				Endpoint_ClearOUT();
+				Endpoint_ClearStatusStage();
 			}
 
 			break;
@@ -378,7 +372,7 @@ void ReceiveNextReport(void)
 void HID_Task(void)
 {
 	/* Device must be connected and configured for the task to run */
-	if (!(USB_IsConnected) || !(USB_ConfigurationNumber))
+	if (USB_DeviceState != DEVICE_STATE_Configured)
 	  return;
 	  
 	/* Send the next keypress report to the host */

Demos/Device/LowLevel/KeyboardMouse/KeyboardMouse.c

@@ -174,7 +174,11 @@ void EVENT_USB_UnhandledControlPacket(void)
 				Endpoint_ClearSETUP();
 				
 				/* Wait until the LED report has been sent by the host */
-				while (!(Endpoint_IsOUTReceived()));
+				while (!(Endpoint_IsOUTReceived()))
+				{
+					if (USB_DeviceState == DEVICE_STATE_Unattached)
+					  return;
+				}
 
 				/* Read in the LED report from the host */
 				uint8_t LEDStatus = Endpoint_Read_Byte();
@@ -195,9 +199,7 @@ void EVENT_USB_UnhandledControlPacket(void)
 				/* Clear the endpoint data */
 				Endpoint_ClearOUT();
 
-				/* Acknowledge status stage */
-				while (!(Endpoint_IsINReady()));
-				Endpoint_ClearIN();
+				Endpoint_ClearStatusStage();
 			}
 			
 			break;
@@ -213,7 +215,7 @@ void Keyboard_HID_Task(void)
 	uint8_t JoyStatus_LCL = Joystick_GetStatus();
 
 	/* Device must be connected and configured for the task to run */
-	if (!(USB_IsConnected) || !(USB_ConfigurationNumber))
+	if (USB_DeviceState != DEVICE_STATE_Configured)
 	  return;
 
 	/* Check if board button is not pressed, if so mouse mode enabled */
@@ -284,7 +286,7 @@ void Mouse_HID_Task(void)
 	uint8_t JoyStatus_LCL = Joystick_GetStatus();
 
 	/* Device must be connected and configured for the task to run */
-	if (!(USB_IsConnected) || !(USB_ConfigurationNumber))
+	if (USB_DeviceState != DEVICE_STATE_Configured)
 	  return;
 
 	/* Check if board button is pressed, if so mouse mode enabled */

Demos/Device/LowLevel/MIDI/MIDI.c

@@ -117,7 +117,7 @@ void MIDI_Task(void)
 	static uint8_t PrevJoystickStatus;
 
 	/* Device must be connected and configured for the task to run */
-	if (!(USB_IsConnected) || !(USB_ConfigurationNumber))
+	if (USB_DeviceState != DEVICE_STATE_Configured)
 	  return;
 
 	Endpoint_SelectEndpoint(MIDI_STREAM_IN_EPNUM);

Demos/Device/LowLevel/MassStorage/Lib/DataflashManager.c

@@ -68,8 +68,12 @@ void DataflashManager_WriteBlocks(const uint32_t BlockAddress, uint16_t TotalBlo
 	Dataflash_SendAddressBytes(0, CurrDFPageByte);
 
 	/* Wait until endpoint is ready before continuing */
-	while (!(Endpoint_IsReadWriteAllowed()));
-
+	while (!(Endpoint_IsReadWriteAllowed()))
+	{
+		if (USB_DeviceState == DEVICE_STATE_Unattached)
+		  return;
+	}
+	
 	while (TotalBlocks)
 	{
 		uint8_t BytesInBlockDiv16 = 0;
@@ -84,7 +88,11 @@ void DataflashManager_WriteBlocks(const uint32_t BlockAddress, uint16_t TotalBlo
 				Endpoint_ClearOUT();
 				
 				/* Wait until the host has sent another packet */
-				while (!(Endpoint_IsReadWriteAllowed()));
+				while (!(Endpoint_IsReadWriteAllowed()))
+				{
+					if (USB_DeviceState == DEVICE_STATE_Unattached)
+					  return;
+				}
 			}
 
 			/* Check if end of dataflash page reached */
@@ -195,7 +203,11 @@ void DataflashManager_ReadBlocks(const uint32_t BlockAddress, uint16_t TotalBloc
 	Dataflash_SendByte(0x00);
 	
 	/* Wait until endpoint is ready before continuing */
-	while (!(Endpoint_IsReadWriteAllowed()));
+	while (!(Endpoint_IsReadWriteAllowed()))
+	{
+		if (USB_DeviceState == DEVICE_STATE_Unattached)
+		  return;
+	}
 	
 	while (TotalBlocks)
 	{
@@ -211,7 +223,11 @@ void DataflashManager_ReadBlocks(const uint32_t BlockAddress, uint16_t TotalBloc
 				Endpoint_ClearIN();
 				
 				/* Wait until the endpoint is ready for more data */
-				while (!(Endpoint_IsReadWriteAllowed()));
+				while (!(Endpoint_IsReadWriteAllowed()))
+				{
+					if (USB_DeviceState == DEVICE_STATE_Unattached)
+					  return;
+				}
 			}
 			
 			/* Check if end of dataflash page reached */

Demos/Device/LowLevel/MassStorage/MassStorage.c

@@ -142,9 +142,7 @@ void EVENT_USB_UnhandledControlPacket(void)
 				/* Indicate that the current transfer should be aborted */
 				IsMassStoreReset = true;			
 
-				/* Acknowledge status stage */
-				while (!(Endpoint_IsINReady()));
-				Endpoint_ClearIN();
+				Endpoint_ClearStatusStage();
 			}
 
 			break;
@@ -158,9 +156,7 @@ void EVENT_USB_UnhandledControlPacket(void)
 				
 				Endpoint_ClearIN();
 				
-				/* Acknowledge status stage */
-				while (!(Endpoint_IsOUTReceived()));
-				Endpoint_ClearOUT();
+				Endpoint_ClearStatusStage();
 			}
 			
 			break;
@@ -172,67 +168,67 @@ void EVENT_USB_UnhandledControlPacket(void)
  */
 void MassStorage_Task(void)
 {
-	/* Check if the USB System is connected to a Host */
-	if (USB_IsConnected)
+	/* Device must be connected and configured for the task to run */
+	if (USB_DeviceState != DEVICE_STATE_Configured)
+	  return;
+	  
+	/* Select the Data Out Endpoint */
+	Endpoint_SelectEndpoint(MASS_STORAGE_OUT_EPNUM);
+	
+	/* Check to see if a command from the host has been issued */
+	if (Endpoint_IsReadWriteAllowed())
 	{
-		/* Select the Data Out Endpoint */
-		Endpoint_SelectEndpoint(MASS_STORAGE_OUT_EPNUM);
-		
-		/* Check to see if a command from the host has been issued */
-		if (Endpoint_IsReadWriteAllowed())
+		/* Indicate busy */
+		LEDs_SetAllLEDs(LEDMASK_USB_BUSY);
+
+		/* Process sent command block from the host */
+		if (ReadInCommandBlock())
 		{
-			/* Indicate busy */
-			LEDs_SetAllLEDs(LEDMASK_USB_BUSY);
+			/* Check direction of command, select Data IN endpoint if data is from the device */
+			if (CommandBlock.Flags & COMMAND_DIRECTION_DATA_IN)
+			  Endpoint_SelectEndpoint(MASS_STORAGE_IN_EPNUM);
 
-			/* Process sent command block from the host */
-			if (ReadInCommandBlock())
+			/* Decode the received SCSI command */
+			SCSI_DecodeSCSICommand();
+
+			/* Load in the CBW tag into the CSW to link them together */
+			CommandStatus.Tag = CommandBlock.Tag;
+
+			/* Load in the data residue counter into the CSW */
+			CommandStatus.DataTransferResidue = CommandBlock.DataTransferLength;
+
+			/* Stall the selected data pipe if command failed (if data is still to be transferred) */
+			if ((CommandStatus.Status == Command_Fail) && (CommandStatus.DataTransferResidue))
+			  Endpoint_StallTransaction();
+
+			/* Return command status block to the host */
+			ReturnCommandStatus();
+			
+			/* Check if a Mass Storage Reset occurred */
+			if (IsMassStoreReset)
 			{
-				/* Check direction of command, select Data IN endpoint if data is from the device */
-				if (CommandBlock.Flags & COMMAND_DIRECTION_DATA_IN)
-				  Endpoint_SelectEndpoint(MASS_STORAGE_IN_EPNUM);
-
-				/* Decode the received SCSI command */
-				SCSI_DecodeSCSICommand();
-
-				/* Load in the CBW tag into the CSW to link them together */
-				CommandStatus.Tag = CommandBlock.Tag;
-
-				/* Load in the data residue counter into the CSW */
-				CommandStatus.DataTransferResidue = CommandBlock.DataTransferLength;
-
-				/* Stall the selected data pipe if command failed (if data is still to be transferred) */
-				if ((CommandStatus.Status == Command_Fail) && (CommandStatus.DataTransferResidue))
-				  Endpoint_StallTransaction();
-
-				/* Return command status block to the host */
-				ReturnCommandStatus();
+				/* Reset the data endpoint banks */
+				Endpoint_ResetFIFO(MASS_STORAGE_OUT_EPNUM);
+				Endpoint_ResetFIFO(MASS_STORAGE_IN_EPNUM);
 				
-				/* Check if a Mass Storage Reset occurred */
-				if (IsMassStoreReset)
-				{
-					/* Reset the data endpoint banks */
-					Endpoint_ResetFIFO(MASS_STORAGE_OUT_EPNUM);
-					Endpoint_ResetFIFO(MASS_STORAGE_IN_EPNUM);
-					
-					Endpoint_SelectEndpoint(MASS_STORAGE_OUT_EPNUM);
-					Endpoint_ClearStall();
-					Endpoint_SelectEndpoint(MASS_STORAGE_IN_EPNUM);
-					Endpoint_ClearStall();
-				}
+				Endpoint_SelectEndpoint(MASS_STORAGE_OUT_EPNUM);
+				Endpoint_ClearStall();
+				Endpoint_SelectEndpoint(MASS_STORAGE_IN_EPNUM);
+				Endpoint_ClearStall();
+			}
 
-				/* Indicate ready */
-				LEDs_SetAllLEDs(LEDMASK_USB_READY);
-			}
-			else
-			{
-				/* Indicate error reading in the command block from the host */
-				LEDs_SetAllLEDs(LEDMASK_USB_ERROR);
-			}
+			/* Indicate ready */
+			LEDs_SetAllLEDs(LEDMASK_USB_READY);
+		}
+		else
+		{
+			/* Indicate error reading in the command block from the host */
+			LEDs_SetAllLEDs(LEDMASK_USB_ERROR);
 		}
-
-		/* Clear the abort transfer flag */
-		IsMassStoreReset = false;
 	}
+
+	/* Clear the abort transfer flag */
+	IsMassStoreReset = false;
 }
 
 /** Function to read in a command block from the host, via the bulk data OUT endpoint. This function reads in the next command block

Demos/Device/LowLevel/Mouse/Mouse.c

@@ -172,9 +172,7 @@ void EVENT_USB_UnhandledControlPacket(void)
 				/* Send the flag to the host */
 				Endpoint_ClearIN();
 
-				/* Acknowledge status stage */
-				while (!(Endpoint_IsOUTReceived()));
-				Endpoint_ClearOUT();
+				Endpoint_ClearStatusStage();
 			}
 			
 			break;
@@ -186,9 +184,7 @@ void EVENT_USB_UnhandledControlPacket(void)
 				/* Set or clear the flag depending on what the host indicates that the current Protocol should be */
 				UsingReportProtocol = (USB_ControlRequest.wValue != 0);
 				
-				/* Acknowledge status stage */
-				while (!(Endpoint_IsINReady()));
-				Endpoint_ClearIN();
+				Endpoint_ClearStatusStage();
 			}
 			
 			break;
@@ -200,9 +196,7 @@ void EVENT_USB_UnhandledControlPacket(void)
 				/* Get idle period in MSB, must multiply by 4 to get the duration in milliseconds */
 				IdleCount = ((USB_ControlRequest.wValue & 0xFF00) >> 6);
 				
-				/* Acknowledge status stage */
-				while (!(Endpoint_IsINReady()));
-				Endpoint_ClearIN();
+				Endpoint_ClearStatusStage();
 			}
 			
 			break;
@@ -217,9 +211,7 @@ void EVENT_USB_UnhandledControlPacket(void)
 				/* Send the flag to the host */
 				Endpoint_ClearIN();
 
-				/* Acknowledge status stage */
-				while (!(Endpoint_IsOUTReceived()));
-				Endpoint_ClearOUT();
+				Endpoint_ClearStatusStage();
 			}
 
 			break;
@@ -314,7 +306,7 @@ void SendNextReport(void)
 void Mouse_Task(void)
 {
 	/* Device must be connected and configured for the task to run */
-	if (!(USB_IsConnected) || !(USB_ConfigurationNumber))
+	if (USB_DeviceState != DEVICE_STATE_Configured)
 	  return;
 	  
 	/* Send the next mouse report to the host */

Demos/Device/LowLevel/RNDISEthernet/RNDISEthernet.c

@@ -285,7 +285,7 @@ void Ethernet_Task(void)
 	   Ethernet frame at a time, so the FrameInBuffer bool is used to indicate when the buffers contain data. */
 
 	/* Device must be connected and configured for the task to run */
-	if (!(USB_IsConnected) || !(USB_ConfigurationNumber))
+	if (USB_DeviceState != DEVICE_STATE_Configured)
 	  return;
 
 	/* Check if a frame has been written to the IN frame buffer */

Demos/Device/LowLevel/USBtoSerial/USBtoSerial.c

@@ -192,9 +192,7 @@ void EVENT_USB_UnhandledControlPacket(void)
 						 CONTROL_LINE_OUT_* masks to determine the RTS and DTR line states using the following code:
 				*/
 
-				/* Acknowledge status stage */
-				while (!(Endpoint_IsINReady()));
-				Endpoint_ClearIN();
+				Endpoint_ClearStatusStage();
 			}
 	
 			break;
@@ -205,7 +203,7 @@ void EVENT_USB_UnhandledControlPacket(void)
 void CDC_Task(void)
 {
 	/* Device must be connected and configured for the task to run */
-	if (!(USB_IsConnected) || !(USB_ConfigurationNumber))
+	if (USB_DeviceState != DEVICE_STATE_Configured)
 	  return;
 	  
 #if 0
@@ -264,7 +262,11 @@ void CDC_Task(void)
 	if (Tx_Buffer.Elements)
 	{
 		/* Wait until Serial Tx Endpoint Ready for Read/Write */
-		while (!(Endpoint_IsReadWriteAllowed()));
+		while (!(Endpoint_IsReadWriteAllowed()))
+		{
+			if (USB_DeviceState == DEVICE_STATE_Unattached)
+			  return;
+		}
 		
 		/* Write the bytes from the buffer to the endpoint while space is available */
 		while (Tx_Buffer.Elements && Endpoint_IsReadWriteAllowed())
@@ -284,8 +286,12 @@ void CDC_Task(void)
 		if (IsFull && !(Tx_Buffer.Elements))
 		{
 			/* Wait until Serial Tx Endpoint Ready for Read/Write */
-			while (!(Endpoint_IsReadWriteAllowed()));
-
+			while (!(Endpoint_IsReadWriteAllowed()))
+			{
+				if (USB_DeviceState == DEVICE_STATE_Unattached)
+				  return;
+			}
+				
 			/* Send an empty packet to terminate the transfer */
 			Endpoint_ClearIN();
 		}
@@ -298,11 +304,8 @@ void CDC_Task(void)
 ISR(USART1_RX_vect, ISR_BLOCK)
 {
 	/* Only store received characters if the USB interface is connected */
-	if (USB_IsConnected)
-	{
-		/* Character received, store it into the buffer */
-		Buffer_StoreElement(&Tx_Buffer, UDR1);
-	}
+	if (USB_DeviceState != DEVICE_STATE_Configured)
+	  Buffer_StoreElement(&Tx_Buffer, UDR1);
 }
 
 /** Reconfigures the USART to match the current serial port settings issued by the host as closely as possible. */