Added new EVENT_USB_Device_StartOfFrame() event, controlled by the new USB_Device_EnableSOFEvents() and USB_Device_DisableSOFEvents() macros to give bus-synchronised millisecond interrupts when in USB device mode.

23 files changed, 83 insertions, 75 deletions

diff --git a/Demos/Device/ClassDriver/GenericHID/GenericHID.c b/Demos/Device/ClassDriver/GenericHID/GenericHID.c
index 13db6bf74..c27558b9e 100644
--- a/Demos/Device/ClassDriver/GenericHID/GenericHID.c
+++ b/Demos/Device/ClassDriver/GenericHID/GenericHID.c
@@ -94,18 +94,12 @@ void SetupHardware(void)
 	/* Hardware Initialization */

 	LEDs_Init();

 	USB_Init();

-

-	/* Millisecond timer initialization, with output compare interrupt enabled for the idle timing */

-	OCR0A  = ((F_CPU / 64) / 1000);

-	TCCR0A = (1 << WGM01);

-	TCCR0B = ((1 << CS01) | (1 << CS00));

-	TIMSK0 = (1 << OCIE0A);

 }

 

 /** Event handler for the library USB Connection event. */

 void EVENT_USB_Device_Connect(void)

 {

-	LEDs_SetAllLEDs(LEDMASK_USB_ENUMERATING);

+	LEDs_SetAllLEDs(LEDMASK_USB_ENUMERATING);	

 }

 

 /** Event handler for the library USB Disconnection event. */

@@ -121,6 +115,8 @@ void EVENT_USB_Device_ConfigurationChanged(void)
 

 	if (!(HID_Device_ConfigureEndpoints(&Generic_HID_Interface)))

 	  LEDs_SetAllLEDs(LEDMASK_USB_ERROR);

+

+	USB_Device_EnableSOFEvents();

 }

 

 /** Event handler for the library USB Unhandled Control Request event. */

@@ -129,8 +125,8 @@ void EVENT_USB_Device_UnhandledControlRequest(void)
 	HID_Device_ProcessControlRequest(&Generic_HID_Interface);

 }

 

-/** ISR to keep track of each millisecond interrupt, for determining the HID class idle period remaining when set. */

-ISR(TIMER0_COMPA_vect, ISR_BLOCK)

+/** Event handler for the USB device Start Of Frame event. */

+void EVENT_USB_Device_StartOfFrame(void)

 {

 	HID_Device_MillisecondElapsed(&Generic_HID_Interface);

 }

diff --git a/Demos/Device/ClassDriver/GenericHID/GenericHID.h b/Demos/Device/ClassDriver/GenericHID/GenericHID.h
index 8cf0afc5d..004daf54a 100644
--- a/Demos/Device/ClassDriver/GenericHID/GenericHID.h
+++ b/Demos/Device/ClassDriver/GenericHID/GenericHID.h
@@ -40,8 +40,6 @@
 		#include <avr/io.h>

 		#include <avr/wdt.h>

 		#include <avr/power.h>

-		#include <avr/interrupt.h>

-		#include <stdbool.h>

 		#include <string.h>

 		

 		#include "Descriptors.h"

@@ -71,6 +69,7 @@
 		void EVENT_USB_Device_Disconnect(void);

 		void EVENT_USB_Device_ConfigurationChanged(void);

 		void EVENT_USB_Device_UnhandledControlRequest(void);

+		void EVENT_USB_Device_StartOfFrame(void);

 

 		bool CALLBACK_HID_Device_CreateHIDReport(USB_ClassInfo_HID_Device_t* const HIDInterfaceInfo, uint8_t* const ReportID,

                                                  void* ReportData, uint16_t* ReportSize);

diff --git a/Demos/Device/ClassDriver/Joystick/Joystick.c b/Demos/Device/ClassDriver/Joystick/Joystick.c
index ea85aadde..b18b7ebc8 100644
--- a/Demos/Device/ClassDriver/Joystick/Joystick.c
+++ b/Demos/Device/ClassDriver/Joystick/Joystick.c
@@ -88,12 +88,6 @@ void SetupHardware(void)
 	LEDs_Init();

 	Buttons_Init();

 	USB_Init();

-

-	/* Millisecond timer initialization, with output compare interrupt enabled for the idle timing */

-	OCR0A  = ((F_CPU / 64) / 1000);

-	TCCR0A = (1 << WGM01);

-	TCCR0B = ((1 << CS01) | (1 << CS00));

-	TIMSK0 = (1 << OCIE0A);

 }

 

 /** Event handler for the library USB Connection event. */

@@ -115,6 +109,8 @@ void EVENT_USB_Device_ConfigurationChanged(void)
 

 	if (!(HID_Device_ConfigureEndpoints(&Joystick_HID_Interface)))

 	  LEDs_SetAllLEDs(LEDMASK_USB_ERROR);

+

+	USB_Device_EnableSOFEvents();

 }

 

 /** Event handler for the library USB Unhandled Control Request event. */

@@ -123,8 +119,8 @@ void EVENT_USB_Device_UnhandledControlRequest(void)
 	HID_Device_ProcessControlRequest(&Joystick_HID_Interface);

 }

 

-/** ISR to keep track of each millisecond interrupt, for determining the HID class idle period remaining when set. */

-ISR(TIMER0_COMPA_vect, ISR_BLOCK)

+/** Event handler for the USB device Start Of Frame event. */

+void EVENT_USB_Device_StartOfFrame(void)

 {

 	HID_Device_MillisecondElapsed(&Joystick_HID_Interface);

 }

diff --git a/Demos/Device/ClassDriver/Joystick/Joystick.h b/Demos/Device/ClassDriver/Joystick/Joystick.h
index 493dfa072..d25ccc139 100644
--- a/Demos/Device/ClassDriver/Joystick/Joystick.h
+++ b/Demos/Device/ClassDriver/Joystick/Joystick.h
@@ -82,6 +82,7 @@
 		void EVENT_USB_Device_Disconnect(void);

 		void EVENT_USB_Device_ConfigurationChanged(void);

 		void EVENT_USB_Device_UnhandledControlRequest(void);

+		void EVENT_USB_Device_StartOfFrame(void);

 

 		bool CALLBACK_HID_Device_CreateHIDReport(USB_ClassInfo_HID_Device_t* const HIDInterfaceInfo, uint8_t* const ReportID,

                                                  void* ReportData, uint16_t* ReportSize);

diff --git a/Demos/Device/ClassDriver/Keyboard/Keyboard.c b/Demos/Device/ClassDriver/Keyboard/Keyboard.c
index 6f0bd1d1a..e609d7acb 100644
--- a/Demos/Device/ClassDriver/Keyboard/Keyboard.c
+++ b/Demos/Device/ClassDriver/Keyboard/Keyboard.c
@@ -89,12 +89,6 @@ void SetupHardware()
 	LEDs_Init();

 	Buttons_Init();

 	USB_Init();

-

-	/* Millisecond timer initialization, with output compare interrupt enabled for the idle timing */

-	OCR0A  = ((F_CPU / 64) / 1000);

-	TCCR0A = (1 << WGM01);

-	TCCR0B = ((1 << CS01) | (1 << CS00));

-	TIMSK0 = (1 << OCIE0A);

 }

 

 /** Event handler for the library USB Connection event. */

@@ -116,6 +110,8 @@ void EVENT_USB_Device_ConfigurationChanged(void)
 

 	if (!(HID_Device_ConfigureEndpoints(&Keyboard_HID_Interface)))

 	  LEDs_SetAllLEDs(LEDMASK_USB_ERROR);

+

+	USB_Device_EnableSOFEvents();

 }

 

 /** Event handler for the library USB Unhandled Control Request event. */

@@ -124,8 +120,8 @@ void EVENT_USB_Device_UnhandledControlRequest(void)
 	HID_Device_ProcessControlRequest(&Keyboard_HID_Interface);

 }

 

-/** ISR to keep track of each millisecond interrupt, for determining the HID class idle period remaining when set. */

-ISR(TIMER0_COMPA_vect, ISR_BLOCK)

+/** Event handler for the USB device Start Of Frame event. */

+void EVENT_USB_Device_StartOfFrame(void)

 {

 	HID_Device_MillisecondElapsed(&Keyboard_HID_Interface);

 }

diff --git a/Demos/Device/ClassDriver/Keyboard/Keyboard.h b/Demos/Device/ClassDriver/Keyboard/Keyboard.h
index 0f7176ce0..ebd83d5c5 100644
--- a/Demos/Device/ClassDriver/Keyboard/Keyboard.h
+++ b/Demos/Device/ClassDriver/Keyboard/Keyboard.h
@@ -85,6 +85,7 @@
 		void EVENT_USB_Device_Disconnect(void);

 		void EVENT_USB_Device_ConfigurationChanged(void);

 		void EVENT_USB_Device_UnhandledControlRequest(void);

+		void EVENT_USB_Device_StartOfFrame(void);

 

 		bool CALLBACK_HID_Device_CreateHIDReport(USB_ClassInfo_HID_Device_t* const HIDInterfaceInfo, uint8_t* const ReportID,

                                                  void* ReportData, uint16_t* ReportSize);

diff --git a/Demos/Device/ClassDriver/KeyboardMouse/KeyboardMouse.c b/Demos/Device/ClassDriver/KeyboardMouse/KeyboardMouse.c
index e21999049..5ac5b8d85 100644
--- a/Demos/Device/ClassDriver/KeyboardMouse/KeyboardMouse.c
+++ b/Demos/Device/ClassDriver/KeyboardMouse/KeyboardMouse.c
@@ -112,12 +112,6 @@ void SetupHardware()
 	Joystick_Init();

 	LEDs_Init();

 	USB_Init();

-

-	/* Millisecond timer initialization, with output compare interrupt enabled for the idle timing */

-	OCR0A  = ((F_CPU / 64) / 1000);

-	TCCR0A = (1 << WGM01);

-	TCCR0B = ((1 << CS01) | (1 << CS00));

-	TIMSK0 = (1 << OCIE0A);

 }

 

 /** Event handler for the library USB Connection event. */

@@ -142,6 +136,8 @@ void EVENT_USB_Device_ConfigurationChanged(void)
 	

 	if (!(HID_Device_ConfigureEndpoints(&Mouse_HID_Interface)))

 	  LEDs_SetAllLEDs(LEDMASK_USB_ERROR);

+

+	USB_Device_EnableSOFEvents();

 }

 

 /** Event handler for the library USB Unhandled Control Request event. */

@@ -151,8 +147,8 @@ void EVENT_USB_Device_UnhandledControlRequest(void)
 	HID_Device_ProcessControlRequest(&Mouse_HID_Interface);

 }

 

-/** ISR to keep track of each millisecond interrupt, for determining the HID class idle period remaining when set. */

-ISR(TIMER0_COMPA_vect, ISR_BLOCK)

+/** Event handler for the USB device Start Of Frame event. */

+void EVENT_USB_Device_StartOfFrame(void)

 {

 	HID_Device_MillisecondElapsed(&Keyboard_HID_Interface);

 	HID_Device_MillisecondElapsed(&Mouse_HID_Interface);

diff --git a/Demos/Device/ClassDriver/KeyboardMouse/KeyboardMouse.h b/Demos/Device/ClassDriver/KeyboardMouse/KeyboardMouse.h
index 297564157..1f47c3e4b 100644
--- a/Demos/Device/ClassDriver/KeyboardMouse/KeyboardMouse.h
+++ b/Demos/Device/ClassDriver/KeyboardMouse/KeyboardMouse.h
@@ -89,6 +89,7 @@
 		void EVENT_USB_Device_Disconnect(void);

 		void EVENT_USB_Device_ConfigurationChanged(void);

 		void EVENT_USB_Device_UnhandledControlRequest(void);

+		void EVENT_USB_Device_StartOfFrame(void);

 

 		bool CALLBACK_HID_Device_CreateHIDReport(USB_ClassInfo_HID_Device_t* const HIDInterfaceInfo, uint8_t* const ReportID,

                                                  void* ReportData, uint16_t* ReportSize);

diff --git a/Demos/Device/ClassDriver/Mouse/Mouse.c b/Demos/Device/ClassDriver/Mouse/Mouse.c
index 32f8ca667..d54aecfaa 100644
--- a/Demos/Device/ClassDriver/Mouse/Mouse.c
+++ b/Demos/Device/ClassDriver/Mouse/Mouse.c
@@ -88,12 +88,6 @@ void SetupHardware(void)
 	LEDs_Init();

 	Buttons_Init();

 	USB_Init();

-

-	/* Millisecond timer initialization, with output compare interrupt enabled for the idle timing */

-	OCR0A  = ((F_CPU / 64) / 1000);

-	TCCR0A = (1 << WGM01);

-	TCCR0B = ((1 << CS01) | (1 << CS00));

-	TIMSK0 = (1 << OCIE0A);

 }

 

 /** Event handler for the library USB WakeUp event. */

@@ -115,6 +109,8 @@ void EVENT_USB_Device_ConfigurationChanged(void)
 

 	if (!(HID_Device_ConfigureEndpoints(&Mouse_HID_Interface)))

 	  LEDs_SetAllLEDs(LEDMASK_USB_ERROR);

+

+	USB_Device_EnableSOFEvents();

 }

 

 /** Event handler for the library USB Unhandled Control Request event. */

@@ -123,8 +119,8 @@ void EVENT_USB_Device_UnhandledControlRequest(void)
 	HID_Device_ProcessControlRequest(&Mouse_HID_Interface);

 }

 

-/** ISR to keep track of each millisecond interrupt, for determining the HID class idle period remaining when set. */

-ISR(TIMER0_COMPA_vect, ISR_BLOCK)

+/** Event handler for the USB device Start Of Frame event. */

+void EVENT_USB_Device_StartOfFrame(void)

 {

 	HID_Device_MillisecondElapsed(&Mouse_HID_Interface);

 }

diff --git a/Demos/Device/ClassDriver/Mouse/Mouse.h b/Demos/Device/ClassDriver/Mouse/Mouse.h
index 05b73c078..325bfc502 100644
--- a/Demos/Device/ClassDriver/Mouse/Mouse.h
+++ b/Demos/Device/ClassDriver/Mouse/Mouse.h
@@ -84,6 +84,7 @@
 		void EVENT_USB_Device_Disconnect(void);

 		void EVENT_USB_Device_ConfigurationChanged(void);

 		void EVENT_USB_Device_UnhandledControlRequest(void);

+		void EVENT_USB_Device_StartOfFrame(void);

 

 		bool CALLBACK_HID_Device_CreateHIDReport(USB_ClassInfo_HID_Device_t* const HIDInterfaceInfo, uint8_t* const ReportID,

                                                  void* ReportData, uint16_t* ReportSize);

diff --git a/Demos/Device/LowLevel/GenericHID/GenericHID.h b/Demos/Device/LowLevel/GenericHID/GenericHID.h
index c03651773..da3d4ac60 100644
--- a/Demos/Device/LowLevel/GenericHID/GenericHID.h
+++ b/Demos/Device/LowLevel/GenericHID/GenericHID.h
@@ -40,7 +40,6 @@
 		#include <avr/io.h>

 		#include <avr/wdt.h>

 		#include <avr/power.h>

-		#include <avr/interrupt.h>

 		#include <stdbool.h>

 		#include <string.h>

 		

@@ -77,6 +76,7 @@
 		void EVENT_USB_Device_Disconnect(void);

 		void EVENT_USB_Device_ConfigurationChanged(void);

 		void EVENT_USB_Device_UnhandledControlRequest(void);

+		void EVENT_USB_Device_StartOfFrame(void);

 

 		void ProcessGenericHIDReport(uint8_t* DataArray);

 		void CreateGenericHIDReport(uint8_t* DataArray);

diff --git a/Demos/Device/LowLevel/Keyboard/Keyboard.c b/Demos/Device/LowLevel/Keyboard/Keyboard.c
index f8310abb4..02f61a528 100644
--- a/Demos/Device/LowLevel/Keyboard/Keyboard.c
+++ b/Demos/Device/LowLevel/Keyboard/Keyboard.c
@@ -85,12 +85,6 @@ void SetupHardware(void)
 	Joystick_Init();

 	LEDs_Init();

 	USB_Init();

-	

-	/* Millisecond timer initialization, with output compare interrupt enabled for the idle timing */

-	OCR0A  = 0x7D;

-	TCCR0A = (1 << WGM01);

-	TCCR0B = ((1 << CS01) | (1 << CS00));

-	TIMSK0 = (1 << OCIE0A);

 }

 

 /** Event handler for the USB_Connect event. This indicates that the device is enumerating via the status LEDs and

@@ -137,6 +131,8 @@ void EVENT_USB_Device_ConfigurationChanged(void)
 	{

 		LEDs_SetAllLEDs(LEDMASK_USB_ERROR);

 	}

+	

+	USB_Device_EnableSOFEvents();

 }

 

 /** Event handler for the USB_UnhandledControlRequest event. This is used to catch standard and class specific

@@ -248,10 +244,8 @@ void EVENT_USB_Device_UnhandledControlRequest(void)
 	}

 }

 

-/** ISR for the timer 0 compare vector. This ISR fires once each millisecond, and increments the

- *  scheduler elapsed idle period counter when the host has set an idle period.

- */

-ISR(TIMER0_COMPA_vect, ISR_BLOCK)

+/** Event handler for the USB device Start Of Frame event. */

+void EVENT_USB_Device_StartOfFrame(void)

 {

 	/* One millisecond has elapsed, decrement the idle time remaining counter if it has not already elapsed */

 	if (IdleMSRemaining)

diff --git a/Demos/Device/LowLevel/Keyboard/Keyboard.h b/Demos/Device/LowLevel/Keyboard/Keyboard.h
index bc478f317..f319ab73b 100644
--- a/Demos/Device/LowLevel/Keyboard/Keyboard.h
+++ b/Demos/Device/LowLevel/Keyboard/Keyboard.h
@@ -40,7 +40,6 @@
 	/* Includes: */

 		#include <avr/io.h>

 		#include <avr/wdt.h>

-		#include <avr/interrupt.h>

 		#include <avr/power.h>

 		#include <stdbool.h>

 		#include <string.h>

@@ -105,6 +104,7 @@
 		void EVENT_USB_Device_Disconnect(void);

 		void EVENT_USB_Device_ConfigurationChanged(void);

 		void EVENT_USB_Device_UnhandledControlRequest(void);

+		void EVENT_USB_Device_StartOfFrame(void);

 

 		void CreateKeyboardReport(USB_KeyboardReport_Data_t* ReportData);

 		void ProcessLEDReport(uint8_t LEDReport);

diff --git a/Demos/Device/LowLevel/KeyboardMouse/KeyboardMouse.h b/Demos/Device/LowLevel/KeyboardMouse/KeyboardMouse.h
index 37cb7f651..57e152b9a 100644
--- a/Demos/Device/LowLevel/KeyboardMouse/KeyboardMouse.h
+++ b/Demos/Device/LowLevel/KeyboardMouse/KeyboardMouse.h
@@ -102,5 +102,6 @@
 		void EVENT_USB_Device_Disconnect(void);

 		void EVENT_USB_Device_ConfigurationChanged(void);

 		void EVENT_USB_Device_UnhandledControlRequest(void);

+		void EVENT_USB_Device_StartOfFrame(void);

 		

 #endif

diff --git a/Demos/Device/LowLevel/Mouse/Mouse.c b/Demos/Device/LowLevel/Mouse/Mouse.c
index 48f04612b..aa95e9c0c 100644
--- a/Demos/Device/LowLevel/Mouse/Mouse.c
+++ b/Demos/Device/LowLevel/Mouse/Mouse.c
@@ -85,12 +85,6 @@ void SetupHardware(void)
 	LEDs_Init();

 	Buttons_Init();

 	USB_Init();

-	

-	/* Millisecond timer initialization, with output compare interrupt enabled for the idle timing */

-	OCR0A  = 0x7D;

-	TCCR0A = (1 << WGM01);

-	TCCR0B = ((1 << CS01) | (1 << CS00));

-	TIMSK0 = (1 << OCIE0A);

 }

 

 /** Event handler for the USB_Connect event. This indicates that the device is enumerating via the status LEDs and

@@ -129,6 +123,8 @@ void EVENT_USB_Device_ConfigurationChanged(void)
 	{

 		LEDs_SetAllLEDs(LEDMASK_USB_ERROR);

 	}

+

+	USB_Device_EnableSOFEvents();

 }

 

 /** Event handler for the USB_UnhandledControlRequest event. This is used to catch standard and class specific

@@ -218,10 +214,8 @@ void EVENT_USB_Device_UnhandledControlRequest(void)
 	}

 }

 

-/** ISR for the timer 0 compare vector. This ISR fires once each millisecond, and increments the

- *  scheduler elapsed idle period counter when the host has set an idle period.

- */

-ISR(TIMER0_COMPA_vect, ISR_BLOCK)

+/** Event handler for the USB device Start Of Frame event. */

+void EVENT_USB_Device_StartOfFrame(void)

 {

 	/* One millisecond has elapsed, decrement the idle time remaining counter if it has not already elapsed */

 	if (IdleMSRemaining)

diff --git a/Demos/Device/LowLevel/Mouse/Mouse.h b/Demos/Device/LowLevel/Mouse/Mouse.h
index b244ffa58..698fe478a 100644
--- a/Demos/Device/LowLevel/Mouse/Mouse.h
+++ b/Demos/Device/LowLevel/Mouse/Mouse.h
@@ -39,7 +39,6 @@
 	/* Includes: */

 		#include <avr/io.h>

 		#include <avr/wdt.h>

-		#include <avr/interrupt.h>

 		#include <avr/power.h>

 		#include <stdbool.h>

 		#include <string.h>

@@ -105,6 +104,7 @@
 		void EVENT_USB_Device_Disconnect(void);

 		void EVENT_USB_Device_ConfigurationChanged(void);

 		void EVENT_USB_Device_UnhandledControlRequest(void);

+		void EVENT_USB_Device_StartOfFrame(void);

 

 		void CreateMouseReport(USB_MouseReport_Data_t* ReportData);

 

diff --git a/LUFA/Drivers/USB/Class/Device/HID.h b/LUFA/Drivers/USB/Class/Device/HID.h
index 0c141e62c..d995c09aa 100644
--- a/LUFA/Drivers/USB/Class/Device/HID.h
+++ b/LUFA/Drivers/USB/Class/Device/HID.h
@@ -119,7 +119,9 @@
 			void HID_Device_USBTask(USB_ClassInfo_HID_Device_t* HIDInterfaceInfo);

 			

 			/** Indicates that a millisecond of idle time has elapsed on the given HID interface, and the interface's idle count should be

-			 *  decremented. This should be called once per millisecond so that hardware key-repeats function correctly.

+			 *  decremented. This should be called once per millisecond so that hardware key-repeats function correctly. It is recommended

+			 *  that this be called by the \ref EVENT_USB_Device_StartOfFrame() event, once SOF events have been enabled via

+			 *  \ref USB_Device_EnableSOFEvents();.

 			 *

 			 *  \param[in,out] HIDInterfaceInfo  Pointer to a structure containing a HID Class configuration and state.

 			 */

diff --git a/LUFA/Drivers/USB/HighLevel/Events.h b/LUFA/Drivers/USB/HighLevel/Events.h
index 1e638314c..4ed6537b7 100644
--- a/LUFA/Drivers/USB/HighLevel/Events.h
+++ b/LUFA/Drivers/USB/HighLevel/Events.h
@@ -234,6 +234,18 @@
 			 *        \ref Group_USBManagement documentation).

 			 */

 			void EVENT_USB_Device_Reset(void);

+

+			/** Event for USB Start Of Frame detection, when enabled. This event fires at the start of each USB

+			 *  frame, once per millisecond, and is synchronised to the USB bus. This can be used as an accurate

+			 *  millisecond timer source when the USB bus is enumerated in device mode to a USB host.

+			 *

+			 *  This event is not normally active - it must be manually enabled and disabled via the

+			 *  \ref USB_Device_EnableSOFEvents() and \ref USB_Device_DisableSOFEvents() commands after enumeration.

+			 *

+			 *  \note This event does not exist if the USB_HOST_ONLY token is supplied to the compiler (see

+			 *        \ref Group_USBManagement documentation).

+			 */

+			void EVENT_USB_Device_StartOfFrame(void);

 		#endif

 		

 	/* Private Interface - For use in library only: */

@@ -264,6 +276,7 @@
 					void EVENT_USB_Device_Suspend(void) ATTR_WEAK ATTR_ALIAS(USB_Event_Stub);

 					void EVENT_USB_Device_WakeUp(void) ATTR_WEAK ATTR_ALIAS(USB_Event_Stub);

 					void EVENT_USB_Device_Reset(void) ATTR_WEAK ATTR_ALIAS(USB_Event_Stub);

+					void EVENT_USB_Device_StartOfFrame(void) ATTR_WEAK ATTR_ALIAS(USB_Event_Stub);

 				#endif

 			#endif

 	#endif

diff --git a/LUFA/Drivers/USB/HighLevel/USBInterrupt.c b/LUFA/Drivers/USB/HighLevel/USBInterrupt.c
index 00fe7d1dc..a8083c92a 100644
--- a/LUFA/Drivers/USB/HighLevel/USBInterrupt.c
+++ b/LUFA/Drivers/USB/HighLevel/USBInterrupt.c
@@ -153,6 +153,13 @@ ISR(USB_GEN_vect, ISR_BLOCK)
 

 		EVENT_USB_Device_Reset();

 	}

+	

+	if (USB_INT_HasOccurred(USB_INT_SOFI) && USB_INT_IsEnabled(USB_INT_SOFI))

+	{

+		USB_INT_Clear(USB_INT_SOFI);

+		

+		EVENT_USB_Device_StartOfFrame();

+	}

 	#endif

 	

 	#if defined(USB_CAN_BE_HOST)

diff --git a/LUFA/Drivers/USB/LowLevel/Device.h b/LUFA/Drivers/USB/LowLevel/Device.h
index d66def438..f107407bf 100644
--- a/LUFA/Drivers/USB/LowLevel/Device.h
+++ b/LUFA/Drivers/USB/LowLevel/Device.h
@@ -111,12 +111,27 @@
 				 *  \return Boolean true if the USB communications have been suspended by the host, false otherwise.

 				 */

 				static inline bool USB_Device_IsUSBSuspended(void);

+				

+				/** Enables the device mode Start Of Frame events. When enabled, this causes the

+				 *  \ref EVENT_USB_Device_StartOfFrame() event to fire once per millisecond, synchronised to the USB bus,

+				 *  at the start of each USB frame when enumerated in device mode.

+				 */

+				static inline bool USB_Device_EnableSOFEvents(void);

+				

+				/** Disables the device mode Start Of Frame events. When disabled, this stop the firing of the

+				 *  \ref EVENT_USB_Device_StartOfFrame() event when enumerated in device mode.

+				 */

+				static inline bool USB_Device_DisableSOFEvents(void);

 			#else

 				#define USB_Device_SendRemoteWakeup()   MACROS{ UDCON |= (1 << RMWKUP); }MACROE

 

 				#define USB_Device_IsRemoteWakeupSent()       ((UDCON &  (1 << RMWKUP)) ? false : true)

 

 				#define USB_Device_IsUSBSuspended()           ((UDINT &  (1 << SUSPI)) ? true : false)

+				

+				#define USB_Device_EnableSOFEvents()    MACROS{ USB_INT_Enable(USB_INT_SOFI); }MACROE

+

+				#define USB_Device_DisableSOFEvents()   MACROS{ USB_INT_Disable(USB_INT_SOFI); }MACROE

 			#endif

 			

 		/* Type Defines: */

diff --git a/LUFA/ManPages/ChangeLog.txt b/LUFA/ManPages/ChangeLog.txt
index fd652217a..de2fa810c 100644
--- a/LUFA/ManPages/ChangeLog.txt
+++ b/LUFA/ManPages/ChangeLog.txt
@@ -11,6 +11,8 @@
   *  <b>New:</b>

   *  - Added new host class drivers and matching demos to the library for rapid application development

   *  - Added flag to the HID report parser to indicate if a device has multiple reports

+  *  - Added new EVENT_USB_Device_StartOfFrame() event, controlled by the new USB_Device_EnableSOFEvents() and

+  *    USB_Device_DisableSOFEvents() macros to give bus-synchronised millisecond interrupts when in USB device mode

   *  

   *  <b>Changed:</b>

   *  - SetIdle requests to the HID device driver with a 0 idle period (send changes only) now only affect the requested

diff --git a/Projects/Magstripe/Magstripe.c b/Projects/Magstripe/Magstripe.c
index 5be34492a..3ea505296 100644
--- a/Projects/Magstripe/Magstripe.c
+++ b/Projects/Magstripe/Magstripe.c
@@ -99,12 +99,6 @@ void SetupHardware(void)
 	/* Hardware Initialization */

 	Magstripe_Init();

 	USB_Init();

-

-	/* Millisecond timer initialization, with output compare interrupt enabled for the idle timing */

-	OCR0A  = ((F_CPU / 64) / 1000);

-	TCCR0A = (1 << WGM01);

-	TCCR0B = ((1 << CS01) | (1 << CS00));

-	TIMSK0 = (1 << OCIE0A);

 }

 

 /** Determines if a card has been inserted, and if so reads in each track's contents into the bit buffers

@@ -148,6 +142,8 @@ void ReadMagstripeData(void)
 void EVENT_USB_Device_ConfigurationChanged(void)

 {

 	HID_Device_ConfigureEndpoints(&Keyboard_HID_Interface);

+	

+	USB_Device_EnableSOFEvents();

 }

 

 /** Event handler for the library USB Unhandled Control Packet event. */

@@ -156,8 +152,8 @@ void EVENT_USB_Device_UnhandledControlRequest(void)
 	HID_Device_ProcessControlRequest(&Keyboard_HID_Interface);

 }

 

-/** Timer 0 CTC ISR, firing once each millisecond to keep track of elapsed idle time in the HID interface. */

-ISR(TIMER0_COMPA_vect, ISR_BLOCK)

+/** Event handler for the USB device Start Of Frame event. */

+void EVENT_USB_Device_StartOfFrame(void)

 {

 	HID_Device_MillisecondElapsed(&Keyboard_HID_Interface);

 }

diff --git a/Projects/Magstripe/Magstripe.h b/Projects/Magstripe/Magstripe.h
index 7cbda8302..aabf6ac91 100644
--- a/Projects/Magstripe/Magstripe.h
+++ b/Projects/Magstripe/Magstripe.h
@@ -84,6 +84,7 @@
 		

 		void EVENT_USB_Device_ConfigurationChanged(void);

 		void EVENT_USB_Device_UnhandledControlRequest(void);

+		void EVENT_USB_Device_StartOfFrame(void);

 

 		bool CALLBACK_HID_Device_CreateHIDReport(USB_ClassInfo_HID_Device_t* const HIDInterfaceInfo, uint8_t* const ReportID,

                                                  void* ReportData, uint16_t* ReportSize);