Host Management
[USB - LUFA/Drivers/USB/USB.h]


Defines

#define USB_HOST_DEVICEADDRESS   1
#define USB_HOST_TIMEOUT_MS   1000
#define HOST_DEVICE_SETTLE_DELAY_MS   1500

Enumerations

enum  USB_Host_States_t {
  HOST_STATE_WaitForDevice = 0,
  HOST_STATE_Unattached = 1,
  HOST_STATE_Attached = 2,
  HOST_STATE_Attached_WaitForDeviceSettle = 3,
  HOST_STATE_Attached_WaitForConnect = 4,
  HOST_STATE_Attached_DoReset = 5,
  HOST_STATE_Powered = 6,
  HOST_STATE_Default = 7,
  HOST_STATE_Default_PostReset = 8,
  HOST_STATE_Default_PostAddressSet = 9,
  HOST_STATE_Addressed = 10,
  HOST_STATE_Configured = 11,
  HOST_STATE_Ready = 12,
  HOST_STATE_Suspended = 13
}
enum  USB_Host_ErrorCodes_t { HOST_ERROR_VBusVoltageDip = 0 }
enum  USB_Host_EnumerationErrorCodes_t {
  HOST_ENUMERROR_NoError = 0,
  HOST_ENUMERROR_WaitStage = 1,
  HOST_ENUMERROR_NoDeviceDetected = 2,
  HOST_ENUMERROR_ControlError = 3,
  HOST_ENUMERROR_PipeConfigError = 4
}

Functions

static void USB_Host_ResetBus (void)
static void USB_Host_IsBusResetComplete (void)
static void USB_Host_ResumeBus (void)
static void USB_Host_SuspendBus (void)
static bool USB_Host_IsBusSuspended (void)
static bool USB_Host_IsDeviceFullSpeed (void)
static bool USB_Host_IsRemoteWakeupSent (void)
static void USB_Host_ClearRemoteWakeupSent (void)
static void USB_Host_ResumeFromWakeupRequest (void)
static bool USB_Host_IsResumeFromWakeupRequestSent (void)

Variables

volatile uint8_t USB_HostState

Detailed Description

USB Host mode related macros and enums. This module contains macros and enums which are used when the USB controller is initialized in host mode.

Define Documentation

#define HOST_DEVICE_SETTLE_DELAY_MS   1500

Constant for the delay in milliseconds after a device is connected before the library will start the enumeration process. Some devices require a delay of up to 5 seconds after connection before the enumeration process can start or incorrect operation will occur.

This value may be overridden in the user project makefile as the value of the HOST_DEVICE_SETTLE_DELAY_MS token, and passed to the compiler using the -D switch.

#define USB_HOST_DEVICEADDRESS   1

Indicates the fixed USB device address which any attached device is enumerated to when in host mode. As only one USB device may be attached to the AVR in host mode at any one time and that the address used is not important (other than the fact that it is non-zero), a fixed value is specified by the library.

#define USB_HOST_TIMEOUT_MS   1000

Constant for the maximum software timeout period of sent USB control transactions to an attached device. If a device fails to respond to a sent control request within this period, the library will return a timeout error code.

This value may be overridden in the user project makefile as the value of the USB_HOST_TIMEOUT_MS token, and passed to the compiler using the -D switch.


Enumeration Type Documentation

Enum for the error codes for the EVENT_USB_DeviceEnumerationFailed() event.

See also:
USB Events for more information on this event.
Enumerator:
HOST_ENUMERROR_NoError  No error occurred. Used internally, this is not a valid ErrorCode parameter value for the EVENT_USB_DeviceEnumerationFailed() event.
HOST_ENUMERROR_WaitStage  One of the delays between enumeration steps failed to complete successfully, due to a timeout or other error.
HOST_ENUMERROR_NoDeviceDetected  No device was detected, despite the USB data lines indicating the attachment of a device.
HOST_ENUMERROR_ControlError  One of the enumeration control requests failed to complete successfully.
HOST_ENUMERROR_PipeConfigError  The default control pipe (address 0) failed to configure correctly.

Enum for the error codes for the EVENT_USB_HostError() event.

See also:
USB Events for more information on this event.
Enumerator:
HOST_ERROR_VBusVoltageDip  VBUS voltage dipped to an unacceptable level. This error may be the result of an attached device drawing too much current from the VBUS line, or due to the AVR's power source being unable to supply sufficient current.

Enum for the various states of the USB Host state machine. Only some states are implemented in the LUFA library - other states are left to the user to implement.

For information on each state, refer to the USB 2.0 specification. Some states have

See also:
USB_HostState, which stores the current host state machine state.
Enumerator:
HOST_STATE_WaitForDevice  Internally implemented by the library.
HOST_STATE_Unattached  Internally implemented by the library.
HOST_STATE_Attached  Internally implemented by the library.
HOST_STATE_Attached_WaitForDeviceSettle  Internally implemented by the library.
HOST_STATE_Attached_WaitForConnect  Internally implemented by the library.
HOST_STATE_Attached_DoReset  Internally implemented by the library.
HOST_STATE_Powered  Internally implemented by the library.
HOST_STATE_Default  Internally implemented by the library.
HOST_STATE_Default_PostReset  Internally implemented by the library.
HOST_STATE_Default_PostAddressSet  Internally implemented by the library.
HOST_STATE_Addressed  May be implemented by the user project.
HOST_STATE_Configured  May be implemented by the user project.
HOST_STATE_Ready  May be implemented by the user project.
HOST_STATE_Suspended  May be implemented by the user project.


Function Documentation

static void USB_Host_ClearRemoteWakeupSent ( void   )  [inline, static]

Clears the flag indicating that a Remote Wakeup request has been issued by an attached device.

static void USB_Host_IsBusResetComplete ( void   )  [inline, static]

Determines if a previously issued bus reset (via the USB_Host_ResetBus() macro) has completed.

Returns:
Boolean true if no bus reset is currently being sent, false otherwise.

static bool USB_Host_IsBusSuspended ( void   )  [inline, static]

Determines if the USB bus has been suspended via the use of the USB_Host_SuspendBus() macro, false otherwise. While suspended, no USB communications can occur until the bus is resumed, except for the Remote Wakeup event from the device if supported.

Returns:
Boolean true if the bus is currently suspended, false otherwise

static bool USB_Host_IsDeviceFullSpeed ( void   )  [inline, static]

Determines if the attached device is currently enumerated in Full Speed mode (12Mb/s), or false if the attached device is enumerated in Low Speed mode (1.5Mb/s).

Returns:
Boolean true if the attached device is enumerated in Full Speed mode, false otherwise

static bool USB_Host_IsRemoteWakeupSent ( void   )  [inline, static]

Determines if the attached device is currently issuing a Remote Wakeup request, requesting that the host resume the USB bus and wake up the device, false otherwise.

Returns:
Boolean true if the attached device has sent a Remote Wakeup request, false otherwise

static bool USB_Host_IsResumeFromWakeupRequestSent ( void   )  [inline, static]

Determines if a resume from Remote Wakeup request is currently being sent to an attached device.

Returns:
Boolean true if no resume request is currently being sent, false otherwise

static void USB_Host_ResetBus ( void   )  [inline, static]

Resets the USB bus, including the endpoints in any attached device and pipes on the AVR host. USB bus resets leave the default control pipe configured (if already configured).

If the USB bus has been suspended prior to issuing a bus reset, the attached device will be woken up automatically and the bus resumed after the reset has been correctly issued.

static void USB_Host_ResumeBus ( void   )  [inline, static]

Resumes USB communications with an attached and enumerated device, by resuming the transmission of the 1MS Start Of Frame messages to the device. When resumed, USB communications between the host and attached device may occur.

static void USB_Host_ResumeFromWakeupRequest ( void   )  [inline, static]

Accepts a Remote Wakeup request from an attached device. This must be issued in response to a device's Remote Wakeup request within 2ms for the request to be accepted and the bus to be resumed.

static void USB_Host_SuspendBus ( void   )  [inline, static]

Suspends the USB bus, preventing any communications from occurring between the host and attached device until the bus has been resumed. This stops the transmission of the 1MS Start Of Frame messages to the device.


Variable Documentation

volatile uint8_t USB_HostState

Indicates the current host state machine state. When in host mode, this indicates the state via one of the values of the USB_Host_States_t enum values in Host.h.

This value may be altered by the user application to implement the HOST_STATE_Addressed, HOST_STATE_Configured, HOST_STATE_Ready and HOST_STATE_Suspended states which are not implemented by the library.

Note:
This global is only present if the user application can be a USB host.


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