* 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
/** 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
+ * 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
/** 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; eack packet within the request transaction must be acknowedged or\r
+ * sent within 50ms or the host will abort the transfer.\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
* frame, once per millisecond, and is synchronised 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 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
+ * 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
projects / pub / USBasp.git / blobdiff