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LUFA Library
120219
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LUFA Library
120219
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USB Controller definitions for the AVR8 microcontrollers. More...
Defines | |
| #define | USB_STREAM_TIMEOUT_MS 100 |
Enumerations | |
| enum | USB_Modes_t { USB_MODE_None = 0, USB_MODE_Device = 1, USB_MODE_Host = 2, USB_MODE_UID = 3, USB_MODE_None = 0, USB_MODE_Device = 1, USB_MODE_Host = 2, USB_MODE_UID = 3, USB_MODE_None = 0, USB_MODE_Device = 1 } |
Functions | |
| static bool | USB_VBUS_GetStatus (void) ATTR_WARN_UNUSED_RESULT ATTR_ALWAYS_INLINE |
| static void | USB_Detach (void) ATTR_ALWAYS_INLINE |
| static void | USB_Attach (void) ATTR_ALWAYS_INLINE |
| void | USB_Init (const uint8_t Mode, const uint8_t Options) |
| void | USB_Disable (void) |
| void | USB_ResetInterface (void) |
Variables | |
| volatile uint8_t | USB_CurrentMode |
| volatile uint8_t | USB_Options |
USB Controller Option Masks | |
| #define | USB_OPT_REG_DISABLED (1 << 1) |
| #define | USB_OPT_REG_ENABLED (0 << 1) |
| #define | USB_OPT_MANUAL_PLL (1 << 2) |
| #define | USB_OPT_AUTO_PLL (0 << 2) |
Functions, macros, variables, enums and types related to the setup and management of the USB interface.
| #define USB_OPT_AUTO_PLL (0 << 2) |
Automatic PLL control option mask for USB_Init(). This indicates to the library that the library should take full responsibility for controlling the AVR's PLL (used to generate the high frequency clock that the USB controller requires) and ensuring that it is locked at the correct frequency for USB operations.
| #define USB_OPT_MANUAL_PLL (1 << 2) |
Manual PLL control option mask for USB_Init(). This indicates to the library that the user application will take full responsibility for controlling the AVR's PLL (used to generate the high frequency clock that the USB controller requires) and ensuring that it is locked at the correct frequency for USB operations.
| #define USB_OPT_REG_DISABLED (1 << 1) |
Regulator disable option mask for USB_Init(). This indicates that the internal 3.3V USB data pad regulator should be disabled and the AVR's VCC level used for the data pads.
| #define USB_OPT_REG_ENABLED (0 << 1) |
Regulator enable option mask for USB_Init(). This indicates that the internal 3.3V USB data pad regulator should be enabled to regulate the data pin voltages from the VBUS level down to a level within the range allowable by the USB standard.
| #define USB_STREAM_TIMEOUT_MS 100 |
Constant for the maximum software timeout period of the USB data stream transfer functions (both control and standard) when in either device or host mode. If the next packet of a stream is not received or acknowledged within this time period, the stream function will fail.
This value may be overridden in the user project makefile as the value of the USB_STREAM_TIMEOUT_MS token, and passed to the compiler using the -D switch.
| enum USB_Modes_t |
Enum for the possible USB controller modes, for initialization via USB_Init() and indication back to the user application via USB_CurrentMode.
| static void USB_Attach | ( | void | ) | [inline, static] |
Attaches the device to the USB bus. This announces the device's presence to any attached USB host, starting the enumeration process. If no host is present, attaching the device will allow for enumeration once a host is connected to the device.
This is inexplicably also required for proper operation while in host mode, to enable the attachment of a device to the host. This is despite the bit being located in the device-mode register and despite the datasheet making no mention of its requirement in host mode.
| static void USB_Detach | ( | void | ) | [inline, static] |
Detaches the device from the USB bus. This has the effect of removing the device from any attached host, ceasing USB communications. If no host is present, this prevents any host from enumerating the device once attached until USB_Attach() is called.
| void USB_Disable | ( | void | ) |
Shuts down the USB interface. This turns off the USB interface after deallocating all USB FIFO memory, endpoints and pipes. When turned off, no USB functionality can be used until the interface is restarted with the USB_Init() function.
| void USB_Init | ( | const uint8_t | Mode, |
| const uint8_t | Options | ||
| ) |
Main function to initialize and start the USB interface. Once active, the USB interface will allow for device connection to a host when in device mode, or for device enumeration while in host mode.
As the USB library relies on interrupts for the device and host mode enumeration processes, the user must enable global interrupts before or shortly after this function is called. In device mode, interrupts must be enabled within 500ms of this function being called to ensure that the host does not time out whilst enumerating the device. In host mode, interrupts may be enabled at the application's leisure however enumeration will not begin of an attached device until after this has occurred.
Calling this function when the USB interface is already initialized will cause a complete USB interface reset and re-enumeration.
| [in] | Mode | This is a mask indicating what mode the USB interface is to be initialized to, a value from the USB_Modes_t enum. |
| [in] | Options | Mask indicating the options which should be used when initializing the USB interface to control the USB interface's behaviour. This should be comprised of a USB_OPT_REG_* mask to control the regulator, a USB_OPT_*_PLL mask to control the PLL, and a USB_DEVICE_OPT_* mask (when the device mode is enabled) to set the device mode speed. |
USB_DEVICE_ONLY (for device mode) or USB_HOST_ONLY (for host mode), passing the token to the compiler via the -D switch. If the mode is statically set, this parameter does not exist in the function prototype. USE_STATIC_OPTIONS token, defined to the appropriate options masks. When the options are statically set, this parameter does not exist in the function prototype. USB_DEVICE_OPT_* masks. | void USB_ResetInterface | ( | void | ) |
Resets the interface, when already initialized. This will re-enumerate the device if already connected to a host, or re-enumerate an already attached device when in host mode.
| static bool USB_VBUS_GetStatus | ( | void | ) | [inline, static] |
Determines if the VBUS line is currently high (i.e. the USB host is supplying power).
true if the VBUS line is currently detecting power from a host, false otherwise. | volatile uint8_t USB_CurrentMode |
Indicates the mode that the USB interface is currently initialized to, a value from the USB_Modes_t enum.
USB_DEVICE_ONLY or USB_HOST_ONLY compile time options, or a limitation of the USB controller in the chosen device model) this will evaluate to a constant of the appropriate value and will never evaluate to USB_MODE_None even when the USB interface is not initialized. | volatile uint8_t USB_Options |
Indicates the current USB options that the USB interface was initialized with when USB_Init() was called. This value will be one of the USB_MODE_* masks defined elsewhere in this module.