USB Interface Management

USB Controller definitions for general USB controller management. More...

Modules
	USB Interface Management (AVR8)
	USB Controller definitions for the AVR8 microcontrollers.
	USB Interface Management (UC3)
	USB Controller definitions for the AVR32 UC3 microcontrollers.
	USB Interface Management (XMEGA)
	USB Controller definitions for the AVR XMEGA microcontrollers.
Functions
void	USB_USBTask (void)
Variables
volatile bool	USB_IsInitialized
USB_Request_Header_t	USB_ControlRequest
Endpoint Direction Masks
#define	ENDPOINT_DIR_MASK   0x80
#define	ENDPOINT_DIR_OUT   0x00
#define	ENDPOINT_DIR_IN   0x80
Endpoint/Pipe Type Masks
#define	EP_TYPE_MASK   0x03
#define	EP_TYPE_CONTROL   0x00
#define	EP_TYPE_ISOCHRONOUS   0x01
#define	EP_TYPE_BULK   0x02
#define	EP_TYPE_INTERRUPT   0x03

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Detailed Description

Functions, macros, variables, enums and types related to the setup and management of the USB interface.

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Define Documentation

#define ENDPOINT_DIR_IN   0x80

Endpoint address direction mask for an IN direction (Device to Host) endpoint. This may be ORed with the index of the address within a device to obtain the full endpoint address.

#define ENDPOINT_DIR_MASK   0x80

Endpoint direction mask, for masking against endpoint addresses to retrieve the endpoint's direction for comparing with the ENDPOINT_DIR_* masks.

#define ENDPOINT_DIR_OUT   0x00

Endpoint address direction mask for an OUT direction (Host to Device) endpoint. This may be ORed with the index of the address within a device to obtain the full endpoint address.

#define EP_TYPE_BULK   0x02

Mask for a BULK type endpoint or pipe.

Note:

See Endpoint Management and Pipe Management for endpoint/pipe functions.

#define EP_TYPE_CONTROL   0x00

Mask for a CONTROL type endpoint or pipe.

Note:

See Endpoint Management and Pipe Management for endpoint/pipe functions.

#define EP_TYPE_INTERRUPT   0x03

Mask for an INTERRUPT type endpoint or pipe.

Note:

See Endpoint Management and Pipe Management for endpoint/pipe functions.

#define EP_TYPE_ISOCHRONOUS   0x01

Mask for an ISOCHRONOUS type endpoint or pipe.

Note:

See Endpoint Management and Pipe Management for endpoint/pipe functions.

#define EP_TYPE_MASK   0x03

Mask for determining the type of an endpoint from an endpoint descriptor. This should then be compared with the EP_TYPE_* masks to determine the exact type of the endpoint.

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Function Documentation

void USB_USBTask

(

void

)

This is the main USB management task. The USB driver requires this task to be executed continuously when the USB system is active (device attached in host mode, or attached to a host in device mode) in order to manage USB communications. This task may be executed inside an RTOS, fast timer ISR or the main user application loop.

The USB task must be serviced within 30ms while in device mode, or within 1ms while in host mode. The task may be serviced at all times, or (for minimum CPU consumption):

• In device mode, it may be disabled at start-up, enabled on the firing of the EVENT_USB_Device_Connect() event and disabled again on the firing of the EVENT_USB_Device_Disconnect() event.

• In host mode, it may be disabled at start-up, enabled on the firing of the EVENT_USB_Host_DeviceAttached() event and disabled again on the firing of the EVENT_USB_Host_DeviceEnumerationComplete() or EVENT_USB_Host_DeviceEnumerationFailed() events.

If in device mode (only), the control endpoint can instead be managed via interrupts entirely by the library by defining the INTERRUPT_CONTROL_ENDPOINT token and passing it to the compiler via the -D switch.

See also:

USB Events for more information on the USB events.

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Variable Documentation

USB_Request_Header_t USB_ControlRequest

Structure containing the last received Control request when in Device mode (for use in user-applications inside of the EVENT_USB_Device_ControlRequest() event, or for filling up with a control request to issue when in Host mode before calling USB_Host_SendControlRequest().

Note:

The contents of this structure is automatically endian-corrected for the current CPU architecture.

volatile bool USB_IsInitialized

Indicates if the USB interface is currently initialized but not necessarily connected to a host or device (i.e. if USB_Init() has been run). If this is false, all other library globals related to the USB driver are invalid.

Note:

This variable should be treated as read-only in the user application, and never manually changed in value.