* listed here. If an event with no user-associated handler is fired within the library, it by default maps to an\r
* internal empty stub function.\r
*\r
- * Each event must only have one associated event handler, but can be raised by multiple sources.\r
+ * Each event must only have one associated event handler, but can be raised by multiple sources by calling the event\r
+ * name just like any regular C function (with any required event parameters).\r
*\r
* @{\r
*/\r
\r
/** Event for USB device attachment. This event fires when a the USB interface is in host mode, and\r
* a USB device has been connected to the USB interface. This is interrupt driven, thus fires before\r
- * the standard \ref EVENT_USB_Device_Connect event and so can be used to programmatically start the USB\r
+ * the standard \ref EVENT_USB_Device_Connect() event and so can be used to programmatically start the USB\r
* management task to reduce CPU consumption.\r
*\r
* \note This event only exists on USB AVR models which supports host mode.\r
/** Event for USB device enumeration completion. This event fires when a the USB interface is\r
* in host mode and an attached USB device has been completely enumerated and is ready to be\r
* controlled by the user application.\r
+ *\r
+ * This event is time-critical; exceeding OS-specific delays within this event handler (typically of around\r
+ * 1 second) when a transaction is waiting to be processed by the device will prevent break communications\r
+ * and cause the host to reset the USB bus.\r
*/\r
void EVENT_USB_Host_DeviceEnumerationComplete(void);\r
\r
/** Event for USB device connection. This event fires when the AVR in device mode and the device is connected\r
* to a host, beginning the enumeration process, measured by a rising level on the AVR's VBUS pin.\r
*\r
- * \note For the smaller USB AVRs (AT90USBXX2) with limited USB controllers, VBUS is not available to the USB controller.\r
+ * This event is time-critical; exceeding OS-specific delays within this event handler (typically of around\r
+ * two seconds) will prevent the device from enumerating correctly.\r
+ *\r
+ * \note For the smaller series 2 USB AVRs with limited USB controllers, VBUS is not available to the USB controller.\r
* this means that the current connection state is derived from the bus suspension and wake up events by default,\r
* which is not always accurate (host may suspend the bus while still connected). If the actual connection state\r
* needs to be determined, VBUS should be routed to an external pin, and the auto-detect behaviour turned off by\r
* passing the NO_LIMITED_CONTROLLER_CONNECT token to the compiler via the -D switch at compile time. The connection\r
* and disconnection events may be manually fired, and the \ref USB_DeviceState global changed manually.\r
*\r
+ * \note This event may fire multiple times during device enumeration on the series 2 USB AVRs with limited USB controllers\r
+ * if NO_LIMITED_CONTROLLER_CONNECT is not defined.\r
+ *\r
* \see USBTask.h for more information on the USB management task and reducing CPU usage.\r
*/\r
void EVENT_USB_Device_Connect(void);\r
/** Event for USB device disconnection. This event fires when the AVR in device mode and the device is disconnected\r
* from a host, measured by a falling level on the AVR's VBUS pin.\r
*\r
- * \note For the smaller USB AVRs (AT90USBXX2) with limited USB controllers, VBUS is not available to the USB controller.\r
+ * \note For the smaller series 2 USB AVRs with limited USB controllers, VBUS is not available to the USB controller.\r
* this means that the current connection state is derived from the bus suspension and wake up events by default,\r
* which is not always accurate (host may suspend the bus while still connected). If the actual connection state\r
* needs to be determined, VBUS should be routed to an external pin, and the auto-detect behaviour turned off by\r
* passing the NO_LIMITED_CONTROLLER_CONNECT token to the compiler via the -D switch at compile time. The connection\r
* and disconnection events may be manually fired, and the \ref USB_DeviceState global changed manually.\r
*\r
+ * \note This event may fire multiple times during device enumeration on the series 2 USB AVRs with limited USB controllers\r
+ * if NO_LIMITED_CONTROLLER_CONNECT is not defined.\r
+ *\r
* \see USBTask.h for more information on the USB management task and reducing CPU usage.\r
*/\r
void EVENT_USB_Device_Disconnect(void);\r
/** Event for unhandled control requests. This event fires when a the USB host issues a control\r
* request to the control endpoint (address 0) that the library does not handle. This may either\r
* be a standard request that the library has no handler code for, or a class specific request\r
- * issued to the device which must be handled appropriately. Due to the strict timing requirements\r
- * on control transfers, interrupts are disabled during control request processing.\r
+ * issued to the device which must be handled appropriately.\r
+ *\r
+ * This event is time-critical; each packet within the request transaction must be acknowledged or\r
+ * sent within 50ms or the host will abort the transfer.\r
+ *\r
+ * The library interally handles all standard control requests with the exceptions of SYNC FRAME,\r
+ * SET DESCRIPTOR and SET INTERFACE. These and all other non-standard control requests will be left\r
+ * for the user to process via this event if desired. If not handled in the user application, requests\r
+ * are automatically STALLed.\r
*\r
* \note This event does not exist if the USB_HOST_ONLY token is supplied to the compiler (see\r
* \ref Group_USBManagement documentation).\r
* selected configuration number while in device mode. This event should be hooked in device\r
* applications to create the endpoints and configure the device for the selected configuration.\r
*\r
+ * This event is time-critical; exceeding OS-specific delays within this event handler (typically of around\r
+ * one second) will prevent the device from enumerating correctly.\r
+ *\r
* This event fires after the value of \ref USB_ConfigurationNumber has been changed.\r
*\r
* \note This event does not exist if the USB_HOST_ONLY token is supplied to the compiler (see\r
* a the USB host requests that the device reset its interface. This event fires after the control\r
* endpoint has been automatically configured by the library.\r
*\r
+ * This event is time-critical; exceeding OS-specific delays within this event handler (typically of around\r
+ * two seconds) will prevent the device from enumerating correctly.\r
+ *\r
* \note This event does not exist if the USB_HOST_ONLY token is supplied to the compiler (see\r
* \ref Group_USBManagement documentation).\r
*/\r
void EVENT_USB_Device_Reset(void);\r
+\r
+ /** Event for USB Start Of Frame detection, when enabled. This event fires at the start of each USB\r
+ * frame, once per millisecond, and is synchronized to the USB bus. This can be used as an accurate\r
+ * millisecond timer source when the USB bus is enumerated in device mode to a USB host.\r
+ *\r
+ * This event is time-critical; it is run once per millisecond and thus long handlers will significantly\r
+ * degrade device performance. This event should only be enabled when needed to reduce device wakeups.\r
+ *\r
+ * \note This event is not normally active - it must be manually enabled and disabled via the\r
+ * \ref USB_Device_EnableSOFEvents() and \ref USB_Device_DisableSOFEvents() commands after enumeration.\r
+ *\r
+ * \note This event does not exist if the USB_HOST_ONLY token is supplied to the compiler (see\r
+ * \ref Group_USBManagement documentation).\r
+ */\r
+ void EVENT_USB_Device_StartOfFrame(void);\r
#endif\r
\r
/* Private Interface - For use in library only: */\r
void EVENT_USB_Device_Suspend(void) ATTR_WEAK ATTR_ALIAS(USB_Event_Stub);\r
void EVENT_USB_Device_WakeUp(void) ATTR_WEAK ATTR_ALIAS(USB_Event_Stub);\r
void EVENT_USB_Device_Reset(void) ATTR_WEAK ATTR_ALIAS(USB_Event_Stub);\r
+ void EVENT_USB_Device_StartOfFrame(void) ATTR_WEAK ATTR_ALIAS(USB_Event_Stub);\r
#endif\r
#endif\r
#endif\r
projects / pub / USBasp.git / blobdiff