USB Events
[USB - LUFA/Drivers/USB/USB.h]


Functions

void EVENT_USB_VBUSChange (void)
void EVENT_USB_VBUSConnect (void)
void EVENT_USB_VBUSDisconnect (void)
void EVENT_USB_Connect (void)
void EVENT_USB_Disconnect (void)
void EVENT_USB_InitFailure (const uint8_t ErrorCode)
void EVENT_USB_UIDChange (void)
void EVENT_USB_HostError (const uint8_t ErrorCode)
void EVENT_USB_DeviceAttached (void)
void EVENT_USB_DeviceUnattached (void)
void EVENT_USB_DeviceEnumerationFailed (const uint8_t ErrorCode, const uint8_t SubErrorCode)
void EVENT_USB_DeviceEnumerationComplete (void)
void EVENT_USB_UnhandledControlPacket (void)
void EVENT_USB_ConfigurationChanged (void)
void EVENT_USB_Suspend (void)
void EVENT_USB_WakeUp (void)
void EVENT_USB_Reset (void)

Detailed Description

This module contains macros and functions relating to the management of library events, which are small pieces of code similar to ISRs which are run when a given condition is met. Each event can be fired from multiple places in the user or library code, which may or may not be inside an ISR, thus each handler should be written to be as small and fast as possible to prevent possible problems.

Events can be hooked by the user application by declaring a handler function with the same name and parameters listed here. If an event with no user-associated handler is fired within the library, it by default maps to an internal empty stub function.

Each event must only have one associated event handler, but can be raised by multiple sources.


Function Documentation

void EVENT_USB_ConfigurationChanged ( void   ) 

Event for USB configuration number changed. This event fires when a the USB host changes the selected configuration number while in device mode. This event should be hooked in device applications to create the endpoints and configure the device for the selected configuration.

This event fires after the value of USB_ConfigurationNumber has been changed.

Note:
This event does not exist if the USB_HOST_ONLY token is supplied to the compiler (see USB Interface Management documentation).

void EVENT_USB_Connect ( void   ) 

Event for USB device connection. This event fires when the AVR is in USB host mode and a device has been attached (but not yet fully enumerated), or when in device mode and the device is connected to a host, beginning the enumeration process.

When in device mode, this can be used to programmatically start the USB management task to reduce CPU usage.

Note:
For the smaller USB AVRs (AT90USBXX2) with limited USB controllers, VBUS is not available to the USB controller. this means that the current connection state is derived from the bus suspension and wake up events by default, which is not always accurate (host may suspend the bus while still connected). If the actual connection state needs to be determined, VBUS should be routed to an external pin, and the auto-detect behaviour turned off by passing the NO_LIMITED_CONTROLLER_CONNECT token to the compiler via the -D switch at compile time. The connection and disconnection events may be manually fired, and the USB_IsConnected global changed manually.
See also:
USBTask.h for more information on the USB management task and reducing CPU usage.

void EVENT_USB_DeviceAttached ( void   ) 

Event for USB device attachment. This event fires when a the USB interface is in host mode, and a USB device has been connected to the USB interface. This is interrupt driven, thus fires before the standard EVENT_USB_Connect event and so can be used to programmatically start the USB management task to reduce CPU consumption.

Note:
This event only exists on USB AVR models which supports host mode.

This event does not exist if the USB_DEVICE_ONLY token is supplied to the compiler (see USB Interface Management documentation).

See also:
TASK(USB_USBTask) for more information on the USB management task and reducing CPU usage.

void EVENT_USB_DeviceEnumerationComplete ( void   ) 

Event for USB device enumeration completion. This event fires when a the USB interface is in host mode and an attached USB device has been completely enumerated and is ready to be controlled by the user application, or when the library is in device mode, and the Host has finished enumerating the device.

void EVENT_USB_DeviceEnumerationFailed ( const uint8_t  ErrorCode,
const uint8_t  SubErrorCode 
)

Event for USB device enumeration failure. This event fires when a the USB interface is in host mode, and an attached USB device has failed to enumerate completely.

Parameters:
ErrorCode Error code indicating the failure reason, a value in USB_Host_EnumerationErrorCodes_t
SubErrorCode Sub error code indicating the reason for failure - for example, if the ErrorCode parameter indicates a control error, this will give the error code returned by the USB_Host_SendControlRequest() function.
Note:
This event only exists on USB AVR models which supports host mode.

This event does not exist if the USB_DEVICE_ONLY token is supplied to the compiler (see USB Interface Management documentation).

void EVENT_USB_DeviceUnattached ( void   ) 

Event for USB device removal. This event fires when a the USB interface is in host mode, and a USB device has been removed the USB interface whether or not it has been enumerated. This can be used to programmatically stop the USB management task to reduce CPU consumption.

Note:
This event only exists on USB AVR models which supports host mode.

This event does not exist if the USB_DEVICE_ONLY token is supplied to the compiler (see USB Interface Management documentation).

See also:
TASK(USB_USBTask) for more information on the USB management task and reducing CPU usage.

void EVENT_USB_Disconnect ( void   ) 

Event for USB device disconnection. This event fires when the AVR is in USB host mode and an attached and enumerated device has been disconnected, or when in device mode and the device is disconnected from the host.

When in device mode, this can be used to programmatically stop the USB management task to reduce CPU usage.

Note:
For the smaller USB AVRs (AT90USBXX2) with limited USB controllers, VBUS is not available to the USB controller. this means that the current connection state is derived from the bus suspension and wake up events by default, which is not always accurate (host may suspend the bus while still connected). If the actual connection state needs to be determined, VBUS should be routed to an external pin, and the auto-detect behaviour turned off by passing the NO_LIMITED_CONTROLLER_CONNECT token to the compiler via the -D switch at compile time. The connection and disconnection events may be manually fired, and the USB_IsConnected global changed manually.
See also:
USBTask.h for more information on the USB management task and reducing CPU usage.

void EVENT_USB_HostError ( const uint8_t  ErrorCode  ) 

Event for USB host error. This event fires when a hardware fault has occurred whilst the USB interface is in host mode.

Parameters:
ErrorCode Error code indicating the failure reason, a value in USB_Host_ErrorCodes_t
Note:
This event only exists on USB AVR models which supports host mode.

This event does not exist if the USB_DEVICE_ONLY token is supplied to the compiler (see USB Interface Management documentation).

void EVENT_USB_InitFailure ( const uint8_t  ErrorCode  ) 

Event for USB initialization failure. This event fires when the USB interface fails to initialize correctly due to a hardware or software fault.

Note:
This event only exists on USB AVR models which support dual role modes.
Parameters:
ErrorCode Error code indicating the failure reason, a value in USB_InitErrorCodes_t

void EVENT_USB_Reset ( void   ) 

Event for USB interface reset. This event fires when the USB interface is in device mode, and a the USB host requests that the device reset its interface. This event fires after the control endpoint has been automatically configured by the library.

Note:
This event does not exist if the USB_HOST_ONLY token is supplied to the compiler (see USB Interface Management documentation).

void EVENT_USB_Suspend ( void   ) 

Event for USB suspend. This event fires when a the USB host suspends the device by halting its transmission of Start Of Frame pulses to the device. This is generally hooked in order to move the device over to a low power state until the host wakes up the device. If the USB interface is enumerated with the USB_OPT_AUTO_PLL option set, the library will automatically suspend the USB PLL before the event is fired to save power.

Note:
This event does not exist if the USB_HOST_ONLY token is supplied to the compiler (see USB Interface Management documentation).
See also:
EVENT_USB_WakeUp() event for accompanying Wake Up event.

void EVENT_USB_UIDChange ( void   ) 

Event for USB mode pin level change. This event fires when the USB interface is set to dual role mode, and the UID pin level has changed to indicate a new mode (device or host). This event fires before the mode is switched to the newly indicated mode but after the EVENT_USB_Disconnect event has fired (if connected before the role change).

Note:
This event only exists on USB AVR models which support dual role modes.

This event does not exist if the USB_DEVICE_ONLY or USB_HOST_ONLY tokens have been supplied to the compiler (see USB Interface Management documentation).

void EVENT_USB_UnhandledControlPacket ( void   ) 

Event for unhandled control requests. This event fires when a the USB host issues a control request to the control endpoint (address 0) that the library does not handle. This may either be a standard request that the library has no handler code for, or a class specific request issued to the device which must be handled appropriately. Due to the strict timing requirements on control transfers, interrupts are disabled during control request processing.

Note:
This event does not exist if the USB_HOST_ONLY token is supplied to the compiler (see USB Interface Management documentation).

Requests should be handled in the same manner as described in the USB 2.0 Specification, or appropriate class specification. In all instances, the library has already read the request SETUP parameters into the USB_ControlRequest structure which should then be used by the application to determine how to handle the issued request.

void EVENT_USB_VBUSChange ( void   ) 

Event for VBUS level change. This event fires when the VBUS line of the USB AVR changes from high to low or vice-versa, before the new VBUS level is sampled and the appropriate action taken.

Note:
This event is only available on USB AVR models which support VBUS notification interrupts.

void EVENT_USB_VBUSConnect ( void   ) 

Event for VBUS attachment. On the AVR models with a dedicated VBUS pin, this event fires when the VBUS line of the USB AVR changes from low to high (after the VBUS events have been handled), signalling the attachment of the USB device to a host, before the enumeration process has begun.

Note:
This event is only available on USB AVR models which support VBUS notification interrupts.

void EVENT_USB_VBUSDisconnect ( void   ) 

Event for VBUS attachment. On the AVR models with a dedicated VBUS pin, this event fires when the VBUS line of the USB AVR changes from high to low (after the VBUS events have been handled), signalling the detatchment of the USB device from a host, regardless of its enumeration state.

Note:
This event is only available on USB AVR models which support VBUS notification interrupts.

void EVENT_USB_WakeUp ( void   ) 

Event for USB wake up. This event fires when a the USB interface is suspended while in device mode, and the host wakes up the device by supplying Start Of Frame pulses. This is generally hooked to pull the user application out of a lowe power state and back into normal operating mode. If the USB interface is enumerated with the USB_OPT_AUTO_PLL option set, the library will automatically restart the USB PLL before the event is fired.

Note:
This event does not exist if the USB_HOST_ONLY token is supplied to the compiler (see USB Interface Management documentation).
See also:
EVENT_USB_Suspend() event for accompanying Suspend event.


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